9 8 Intake Design (HIS)

9 Sylvan WayParsippany, New Jersey07054-3802 www.pumps.org

AN

SI/H

I9.

8-19

98

ANSI/HI 9.8-1998

American National Standard for

Pump Intake Design

http://www.pumps.org

Copyright © 2000 By Hydraulic Institute, All Rights Reserved.

This page intentionally blank.


ANSI/HI 9.8-1998

American National Standard for

Pump Intake Design

Sponsor

Hydraulic Institute

www.pumps.org

Approved November 17, 1998

American National Standards Institute, Inc.

Recycledpaper



Approval of an American National Standard requires verification by ANSI that therequirements for due process, consensus and other criteria for approval have been metby the standards developer.

Consensus is established when, in the judgement of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materially affectedinterests. Substantial agreement means much more than a simple majority, but not nec-essarily unanimity. Consensus requires that all views and objections be considered,and that a concerted effort be made toward their resolution.

The use of American National Standards is completely voluntary; their existence doesnot in any respect preclude anyone, whether he has approved the standards or not,from manufacturing, marketing, purchasing, or using products, processes, or proce-dures not conforming to the standards.

The American National Standards Institute does not develop standards and will in nocircumstances give an interpretation of any American National Standard. Moreover, noperson shall have the right or authority to issue an interpretation of an AmericanNational Standard in the name of the American National Standards Institute. Requestsfor interpretations should be addressed to the secretariat or sponsor whose nameappears on the title page of this standard.

CAUTION NOTICE: This American National Standard may be revised or withdrawn atany time. The procedures of the American National Standards Institute require thataction be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers ofAmerican National Standards may receive current information on all standards by call-ing or writing the American National Standards Institute.

Published By

Hydraulic Institute9 Sylvan Way, Parsippany, NJ 07054-3802

www.pumps.org

Copyright © 1998 Hydraulic InstituteAll rights reserved.

No part of this publication may be reproduced in any form,in an electronic retrieval system or otherwise, without priorwritten permission of the publisher.

Printed in the United States of America

ISBN 1-880952-26-2

AmericanNationalStandard



iii

ContentsPage

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Pump Intake Design

9.8 Pump intake design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

9.8.1 Design objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

9.8.2 Intake structures for clear liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

9.8.3 Intake structures for solids-bearing liquids . . . . . . . . . . . . . . . . . . . . . . 15

9.8.4 Pump suction piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

9.8.5 Model tests of intake structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

9.8.6 Inlet bell design diameter (D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

9.8.7 Required submergence for minimizing surface vortices . . . . . . . . . . . . 29

9.8.8 Glossary and nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Appendix A Remedial Measures for Problem Intakes . . . . . . . . . . . . . . . . . . . 42

A-1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

A-2 Approach flow patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

A-2.1 Open vs. partitioned structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

A-3 Controlling cross-flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

A-4 Expanding concentrated flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

A-4.1 Free-surface approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

A-4.2 Closed conduit approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

A-5 Pump inlet disturbances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

A-5.1 Free-surface vortices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

A-5.2 Sub-surface vortices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

A-5.3 Pre-swirl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

A-5.4 Velocities in pump bell throat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

A-6 Tanks — suction inlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Appendix B Sump Volume. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

B-1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

B-2 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

B-3 Minimum sump volume sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

B-4 Decreasing sump volume by pump alternation. . . . . . . . . . . . . . . . . . . . . 57

Appendix C Intake Basin Entrance Conditions . . . . . . . . . . . . . . . . . . . . . . . . 58

C-1 Variable speed pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

C-2 Constant speed pumping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58


iv

C-2.1 Inlet pipe, trench-type wet wells. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

C-2.2 Storage in approach pipe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

C-3 Transition manhole, sewer to approach pipe . . . . . . . . . . . . . . . . . . . . . . 59

C-4 Sluice gate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

C-5 Lining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

C-6 Design examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Appendix D Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Appendix E Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figures

9.8.1 — Recommended intake structure layout . . . . . . . . . . . . . . . . . . . . . . . . . . 3

9.8.2 — Filler wall details for proper bay width . . . . . . . . . . . . . . . . . . . . . . . . . . 3

9.8.3 — Type 10 formed suction intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

9.8.4A — Wet pit duplex sump with pumps offset . . . . . . . . . . . . . . . . . . . . . . . . 7

9.8.4B — Wet pit duplex sump with pumps centerline. . . . . . . . . . . . . . . . . . . . . 7

9.8.4C — Dry pit/wet pit duplex sump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

9.8.5A — Wet pit triplex sump, pumps in line . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

9.8.5B — Wet pit triplex sump, compact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

9.8.5C — Dry pit/wet pit triplex sump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

9.8.6 — Trench-type wet well . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

9.8.7 — Trench-type wet well with formed suction inlet . . . . . . . . . . . . . . . . . . . . 9

9.8.8 — Datum for calculation of submergence. . . . . . . . . . . . . . . . . . . . . . . . . 10

9.8.9 — Definitions of V and D for calculation of submergence. . . . . . . . . . . . . 11

9.8.10 — Open bottom can intakes (pumps less than 315 l/s [5000 gpm]) . . . . 12

9.8.11 — Closed bottom can . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

9.8.12 — Submersible vertical turbine pump . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

9.8.13 — Open trench-type wet well . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

9.8.14 — Open trench-type wet well for pumps sensitive to loss of prime. . . . . 16

9.8.15 — Circular wet pit with sloping walls and minimized horizontalfloor area (submersible pumps shown for illustration) . . . . . . . . . . . . . . . . . . . . 18

9.8.16 — Circular wet pit with sloping walls and minimized horizontalfloor area (dry pit pumps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

9.8.17 — Confined wet wall design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

9.8.18 — Common intakes for suction piping showing submergencedatum references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

9.8.19 — Recommended suction piping near pump, all pump types(D = pipe diameter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

9.8.20 — Examples of suction pipe fittings near pump that requireapproval of the pump manufacturer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22


v

9.8.21 — Recommended suction piping for double suction pumpswith the elbow in the same plane as the impeller shaft . . . . . . . . . . . . . . . . . . . 22

9.8.22 — Suction header design options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9.8.23 — Classification of free surface and sub-surface vortices . . . . . . . . . . . 26

9.8.24 — Typical swirl meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

9.8.25A — Recommended inlet bell design diameter (OD) . . . . . . . . . . . . . . . . 30

9.8.25B — Recommended inlet bell design diameter (OD) (US units) . . . . . . . 31

9.8.26A — Recommended minimum submergence to minimize freesurface vortices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

9.8.26B — Recommended minimum submergence to minimize freesurface vortices (US units) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

A.1 — Examples of approach flow conditions at intake structures andthe resulting effect on velocity, all pumps operating . . . . . . . . . . . . . . . . . . . . . 43

A.2 — Examples of pump approach flow patterns for variouscombinations of operating pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

A.3 — Comparison of flow patterns in open and partitioned sumps . . . . . . . . . 45

A.4 — Effect of trash rack design and location on velocity distributionentering pump bay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

A.5 — Flow-guiding devices at entrance to individual pump bays . . . . . . . . . . . 46

A.6 — Concentrated influent configuration, with and without flowdistribution devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

A.7 — Baffling to improve flow pattern downstream from dual flow screen . . . . 47

A.8 — Typical flow pattern through a dual flow screen . . . . . . . . . . . . . . . . . . . 48

A.9 — Improvements to approach flow without diverging sump walls . . . . . . . . 49

A.10 — Elevation view of a curtain wall for minimizing surface vortices . . . . . . 49

A.11 — Methods to reduce sub-surface vortices (examples A–I) . . . . . . . . . . . 51

A.12 — Anti-vortex devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

B.1 — Operational sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

B.2 — Pump and system head curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Tables

Table 9.8.1 — Recommended dimensions for Figures 9.8.1 and 9.8.2. . . . . . . . 4

Table 9.8.2 — Design sequence, rectangular intake structures . . . . . . . . . . . . . 5

Table 9.8.3 — Acceptable velocity ranges for inlet bell diameter “D”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table C.1 — Maximum flow in approach pipes with hydraulic jump—metric units,slope = 2%, Manning’s n = 0.010. Sequent depth = 60% pipe diameter. Afterwheeler (1995). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table C.2 — Maximum flow in approach pipes with hydraulic jump—US customaryunits, slope = 2%, Manning’s n = 0.010. Sequent depth = 60% pipe diameter. AfterWheeler (1995). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60




vii

Foreword (Not part of Standard)

Purpose and aims of the Hydraulic Institute

The purpose and aims of the Institute are to promote the continued growth andwell-being of pump manufacturers and further the interests of the public in suchmatters as are involved in manufacturing, engineering, distribution, safety, trans-portation and other problems of the industry, and to this end, among other things:

a) To develop and publish standards for pumps;

b) To collect and disseminate information of value to its members and to thepublic;

c) To appear for its members before governmental departments and agenciesand other bodies in regard to matters affecting the industry;

d) To increase the amount and to improve the quality of pump service to the public;

e) To support educational and research activities;

f) To promote the business interests of its members but not to engage in busi-ness of the kind ordinarily carried on for profit or to perform particular servicesfor its members or individual persons as distinguished from activities toimprove the business conditions and lawful interests of all of its members.

Purpose of Standards

1) Hydraulic Institute Standards are adopted in the public interest and aredesigned to help eliminate misunderstandings between the manufacturer,the purchaser and/or the user and to assist the purchaser in selecting andobtaining the proper product for a particular need.

2) Use of Hydraulic Institute Standards is completely voluntary. Existence ofHydraulic Institute Standards does not in any respect preclude a memberfrom manufacturing or selling products not conforming to the Standards.

Definition of a Standard of the Hydraulic Institute

Quoting from Article XV, Standards, of the By-Laws of the Institute, Section B:

“An Institute Standard defines the product, material, process or procedure withreference to one or more of the following: nomenclature, composition, construc-tion, dimensions, tolerances, safety, operating characteristics, performance, qual-ity, rating, testing and service for which designed.”

Comments from users

Comments from users of this Standard will be appreciated, to help the HydraulicInstitute prepare even more useful future editions. Questions arising from the con-tent of this Standard may be directed to the Hydraulic Institute. It will direct allsuch questions to the appropriate technical committee for provision of a suitableanswer.

If a dispute arises regarding contents of an Institute publication or an answer pro-vided by the Institute to a question such as indicated above, the point in questionshall be referred to the Executive Committee of the Hydraulic Institute, which thenshall act as a Board of Appeals.


viii

Revisions

The Standards of the Hydraulic Institute are subject to constant review, and revi-sions are undertaken whenever it is found necessary because of new develop-ments and progress in the art. If no revisions are made for five years, thestandards are reaffirmed using the ANSI canvas procedure.

Over the past several decades, long-term performance results for many differentcentrifugal and axial flow pumping facilities have become available. Based onsome less than satisfactory results, the industry has recognized a need for updat-ing the standard approaches to designing pump intake structures and suction pip-ing. In response to this evolving need, the Hydraulic Institute has improved andexpanded its recommendations for designing intake structures for centrifugal, ver-tical turbine, mixed-flow, and axial-flow pumps and added intake designs for solids-bearing liquids.

This standard is a result of the combined efforts of a balanced committee that wasformed to reflect the perspectives of sump designers, hydraulic researchers, pumpmanufacturers, and end users. It replaces ANSI/HI 1.1-1.5-1994 Section 1.3.3.6and ANSI/HI 2.1-2.5-1994 Section 2.3.5.

The intent of this current edition of the pump intake design standard is to providedesigners, owners and users of pumping facilities a foundation upon which todevelop functional and economical pumping facility designs. The material hasbeen prepared with the deliberate goals of both increasing understanding of thesubject and establishing firm design requirements.

Scope

This standard provides intake design recommendations for both suction pipes andall types of wet pits. While specific intake design is beyond the scope of the pumpmanufacturer’s responsibility, their comments may be helpful to the intakedesigner.

Units of Measurement

Metric units of measurement are used; and corresponding US units appear inbrackets. Charts, graphs and sample calculations are also shown in both metricand US units.

Since values given in metric units are not exact equivalents to values given in USunits, it is important that the selected units of measure to be applied be stated inreference to this standard. If no such statement is provided, metric units shall govern.

Consensus

Consensus for this standard was achieved by use of the canvas method. The fol-lowing organizations, recognized as having interest in the pump intake designswere contacted prior to the approval of this revision of the standard. Inclusion inthis list does not necessarily imply that the organization concurred with the sub-mittal of the proposed standard to ANSI.

Ahlstrom Pumps, LLCAlden Research Laboratory, Inc.Bechtel CorporationBlack & VeatchBrown & CaldwellCamp Dresser & McKee

CH2M HillChas S. Lewis & Co., Inc.Crane Pump & SystemsDavid Brown Union Pump CompanyDeWante & StowellDow Chemical


ix

Electric Power Research InstituteENSR Consulting & EngineeringEquistar L.P.Essco PumpFairbanks Morse PumpFlorida Power CorporationFloway PumpsFlowserve CorporationIngersoll-Dresser PumpITT A-C PumpITT Fluid TechnologyITT Goulds PumpIwaki Walchem CorpJ.P. Messina Pump and Hydraulics

ConsultantJohn Crane, Inc.Johnston Pump CompanyLawrence Pumps, Inc.M. W. KelloggMalcolm Pirnie, Inc.Marine Machinery AssociationMontana State University

Montgomery WatsonMWINational Pump CompanyPACO PumpsPatterson Pump CompanyPrice PumpRaytheon Engineers & ConstructorsRobert Bein, William Frost & Assoc.Sewage & Water Board of New OrleansSkidmoreSolutia, Inc.South Florida Water Management

DistrictSouthern Company Services, Inc.Sta-Rite IndustriesStone and WebsterSulzer Binhham Pumps, Inc.Summers Engineering, Inc.Systecon, Inc.Tennessee Valley AuthorityUS Bureau of Reclamation

Committee List

Although this standard was processed and approved for submittal to ANSI by thecanvas method, a working committee met many times to facilitate the develop-ment of this standard. At the time it was approved, the committee had the follow-ing members:

NAME COMPANY CATEGORYJack Claxton, Chairman Patterson Pump Company ProducerStefan Abelin, Vice Chair. ITT Flygt Corp. ProducerWilliam Beekman Floway Pumps ProducerThomas Demlow ENSR Consulting & Engineering General InterestThomas Duncan Southern Company Services, Inc. UserPeter Garvin Bechtel Corporation General InterestHerman Greutink Johnston Pump Company ProducerJames Healy Stone and Webster General InterestGeorge E. Hecker Alden Research Laboratory Inc. General InterestJoseph Jackson Yeomans Chicago Corp. ProducerGarr Jones Brown & Caldwell General InterestZan Kugler South Florida Water Management

DistrictUser

James Leech US Army Corps of Engineers UserFrederick Locher Bechtel Corporation General InterestWilbur Norwood (Alternate) Yeomans Chicago Corp. ProducerRobert Sanks Montana State University General InterestGerald Schohl Tennesse Valley Authority UserArnold Sdano Fairbanks Morse Pump ProducerG. Joseph Sullivan Sewerage & Water Board of New

OrleansUser

Zbigniew Czarnota(Alternate)

ITT Flygt Corp. Producer


x

Major Revisions

Past Hydraulic Institute intake design standards have been based on the ratedflow rate of the pump, while several other pump intake guidelines are based ondimensions determined from multiples of the inlet bell diameter.

Recognizing that a balance between these concepts may optimize the intakedesign, this edition is based upon:

• the pump intake bell outside diameter called “design diameter” or simply “D”

• an acceptable average velocity range across D (see Table 9.8.3)

• verification that the approach velocity does not exceed specified limits

• submergence “S” of pump intakes as a function of Froude number “FD” and D

This edition consists of the “standard,” Section 9.8, Intake Design Standards, andseveral appendices. These appendices are included as educational informationand are not part of the standard. Illustrations of “Not Recommended” designshave been eliminated, as they are too numerous to document properly.

Other major changes introduced by this standard are given below under each sub-ject heading.

Rectangular Intakes

The dimensioning for rectangular plan intakes has been changed from a flow-based design to one based on D, as determined by the inlet bell velocity. A parti-tioned intake design is recommended over an open intake design.

Reference sections (9.8.2.1 and 9.8.3.4)

Formed Suction Intakes

This standard introduces recommendations for the formed suction inlet.

Reference sections (9.8.2.2)

Circular Intakes

This standard introduces recommendations for the appropriate use of circular wetwells for both clear and solids-bearing liquids, and it suggests specific configurations.


Trench-Type Intakes

This standard introduces geometry for trench-type wet wells for both clear and solids-bearing liquids.


Suction Tanks

Guidelines are provided for suction tank applications.

Reference section (9.8.2.5)


xi

Barrel or Can and Submersible Vertical Turbine Intakes

Recommendations for barrel or can-type intakes and submersible vertical turbineintakes designs are introduced.


Unconfined Intakes

Guidelines are provided for unconfined intake applications.


Solids-Bearing Liquids Applications

In past editions of this standard, discussions of solids-bearing liquids were limitedto advising designers to obtain specific recommendations from pump manufactur-ers. This standard provides recommendations for pump sump designs intendedfor solids-bearing liquids. It addresses the special considerations of keeping wetwells clean and maintaining minimum velocities. Specific recommendations forwet well geometries are provided.

Reference section (9.8.3)

Pump Suction Piping

The section on suction piping has been rewritten and condensed. It provides infor-mation and specific recommendations for suction piping design, suction headers,and design recommendations for solids-bearing liquids.


Model Testing

The discussion of sump model testing has been expanded to include:

• factors for determining when a model test is necessary

• scaling criteria for determining adequate model size and proper flow rates

• recommended instrumentation and testing methods

• acceptance criteria for wet well and suction piping hydraulic performance


Inlet Bell Diameter

When the bell diameter “D” has not been established, the standard uses a“Design Bell Diameter” based on an acceptable velocity range for determination ofsump geometry.


Submergence

The submergence “S” of pump intakes is determined as a function of inlet bellFroude number “FD” and D.


xii

Submergence requirements for the bell or pipe intake, as calculated with this stan-dard, are generally less than the values specified by the 13th edition, but morethan those required by the 14th edition of the Hydraulic Institute standards.


Appendix

These appendices are not part of this standard, but are presented to helpthe user in considering factors beyond the standard sump design.

Appendices have been added to include:

a) Remedial Measures for Problem Intakes

b) Sump Volume (calculations with considerations given for cyclical operation ofconstant speed pumps)

c) Intake Basin Entrance Conditions

d) Bibliography

Disclaimers

This document presents accepted best practices based upon information avail-able to the Hydraulic Institute as of the date of publication. Nothing presentedherein is to be construed as a warranty of successful performance under any con-ditions for any application.


xiii

Flow Chart For Use Of Standard

NOTE: This flow chart is intended as a guide to the use of this standard andcan be used to locate the appropriate sections in this standard. The chart is nota substitute for the understanding of the complete standard.

START

IS THERE AFREE LIQUIDSURFACE ?

CAN PUMPS(SECTION

9.8.2.6)

SUCTION PIPING(SECTION

9.8.4)

CLOSEDBOTTOM

(SECTION9.8.2.6.5)

OPENBOTTOM

(SECTION9.8.2.6.4)

INLET BELL DESIGN DIAMETER (SECTION 9.8.6)

SUBMERGENCE(SECTION 9.8.7)

CLEARLIQUID ?

TRENCH TYPEINTAKE

(SECTION9.8.3.2)

RECTANGULARINTAKE

(SECTION9.8.3.4)

CIRCULARINTAKE

(SECTION9.8.3.3)

RECTANGULARINTAKE

(SECTION 9.8.2.1)

CIRCULARINTAKE

(SECTION 9.8.2.3)

TRENCHTYPE

INTAKE(SECTION

9.8.2.4)

UNCONFINEDINTAKE

(SECTION 9.8.2.7)

FORMEDSUCTIONINTAKE

(SECTION9.8.2.2)

SUCTIONTANKS

(SECTION9.8.2.5)

YES

FLOW > 100,000 GPM PERSTATION OR >40,000 GPM

PER PUMP ?

NO

YES

NO

END

NO

FLOW PERPUMP

> 5000 GPM ?

END

NO

MODEL TESTREQUIRED

(SECTION 9.8.5)

YES

YES

END




HI Pump Intake Design — 1998

1

Pump Intake Design

9.8 Pump intake design

Metric units of measurement are used; and corre-sponding US units appear in brackets. Charts, graphsand sample calculations are also shown in both metricand US units.

Since values given in metric units are not exact equiv-alents to values given in US units, it is important thatthe selected units of measure be stated in reference tothis standard. If no such statement is provided, metricunits shall govern. See Section 9.8.8 for Glossary andNomenclature.

In the application of this standard, the pump rated flowshall be used as the design flow for the basis of theintake design.

9.8.1 Design objectives

Specific hydraulic phenomena have been identifiedthat can adversely affect the performance of pumps.Phenomena that must not be present to an excessivedegree are:

• Submerged vortices

• Free-surface vortices

• Excessive pre-swirl of flow entering the pump

• Non-uniform spatial distribution of velocity at theimpeller eye

• Excessive variations in velocity and swirl with time

• Entrained air or gas bubbles

The negative impact of each of these phenomena onpump performance depends on pump specific speedand size, as well as other design features of the pumpthat are specific to a given pump manufacturer. In gen-eral, large pumps and axial flow pumps (high specificspeed) are more sensitive to adverse flow phenomenathan small pumps or radial flow pumps (low specificspeed). A more quantitative assessment of whichpump types may be expected to withstand a givenlevel of adverse phenomena with no ill effects has notbeen performed. Typical symptoms of adverse hydrau-lic conditions are reduced flow rate, head, effects onpower, and increased vibration and noise.

The intake structure should be designed to allow thepumps to achieve their optimum hydraulic perfor-mance for all operating conditions. A good designensures that the adverse flow phenomena describedabove are within the limits outlined in Section 9.8.5.6.

If an intake is designed to a geometry other thanthat presented in this standard, and this design isshown by prototype or model tests, performed inaccordance with Section 9.8.5, to meet the accep-tance criteria in Section 9.8.5.6, then this alterna-tive design shall be deemed to comply with thisstandard.

9.8.2 Intake structures for clear liquids

9.8.2.1 Rectangular intakes

This section is applicable to wet pit pumps. This sec-tion also applies to the intakes for dry pit pumps withless than five diameters of suction piping immediatelyupstream from the pump (see Section 9.8.4).

9.8.2.1.1 Approach flow patterns

The characteristics of the flow approaching an intakestructure is one of the most critical considerations forthe designer. When determining direction and distribu-tion of flow at the entrance to a pump intake structure,the following must be considered:

• The orientation of the structure relative to the bodyof supply liquid

• Whether the structure is recessed from, flush with,or protrudes beyond the boundaries of the body ofsupply liquid

• Strength of currents in the body of supply liquidperpendicular to the direction of approach to thepumps

• The number of pumps required and their antici-pated operating combinations

The ideal conditions, and the assumptions upon whichthe geometry and dimensions recommended for rec-tangular intake structures are based, are that thestructure draws flow so that there are no cross-flows inthe vicinity of the intake structure that create asymmet-ric flow patterns approaching any of the pumps, and



2

the structure is oriented so that the supply boundary issymmetrical with respect to the centerline of the struc-ture. As a general guide, cross-flow velocities are sig-nificant if they exceed 50% of the pump bay entrancevelocity. Section 9.8.5 provides recommendations foranalyzing departures from this ideal condition basedupon a physical hydraulic model study.

9.8.2.1.2 Open vs. partitioned structures

If multiple pumps are installed in a single intake struc-ture, dividing walls placed between the pumps result inmore favorable flow conditions than found in opensumps. Adverse flow patterns can frequently occur ifdividing walls are not used. For pumps with designflows greater than 315 l/s (5,000 gpm) dividing wallsbetween pumps are required.

9.8.2.1.3 Trash racks and screens

Partially clogged trash racks or screens can createseverely skewed flow patterns. If the application issuch that screens or trash racks are susceptible toclogging, they must be inspected and cleaned as fre-quently as necessary to prevent adverse effects onflow patterns.

Any screen-support structure that disrupts flow, suchas dual-flow traveling screens, otherwise known asdouble-entry single-exit screens, can create a high-velocity jet and severe instability near the pumps. Aphysical hydraulic model study must be performed inevery such case. The screen exit should be placed aminimum distance of six bell diameters, 6D, (see Sec-tion 9.8.6) from the pumps. However, this distanceshould be used only as a general guideline for initiallayouts of structures, with final design developed withthe aid of a physical model study.

The recommendations in this standard should be fol-lowed if suction bell strainers are used.

9.8.2.1.4 Recommendations for dimensioning rectangular intake structures

The basic design requirements for satisfactory hydrau-lic performance of rectangular intake structuresinclude:

• Adequate depth of flow to limit velocities in thepump bays and reduce the potential for formula-tion of surface vortices

• Adequate pump bay width, in conjunction with thedepth, to limit the maximum pump approach

velocities to 0.5 m/s (1.5 ft/s), but narrow and longenough to channel flow uniformly toward the pumps

The minimum submergence, S, required to preventstrong air core vortices is based in part on a dimension-less flow parameter, the Froude number, defined as:

FD = V/(gD)0.5 (9.8.2.1-1)

Where:

FD = Froude number (dimensionless)

V = Velocity at suction inlet = Flow/Area,based on D

D = Outside diameter of bell or pipe inlet

g = gravitational acceleration

Consistent units must be used for V, D and g so thatFD is dimensionless. The minimum submergence, S,shall be calculated from (Hecker, G.E., 1987),

S = D(1+2.3FD) (9.8.2.1-2)

where the units of S are those used for D. Section9.8.7 provides further information on the backgroundand development of this relationship.

It is appropriate to specify sump dimensions in multi-ples of pump bell diameters “D” (see Section 9.8.6).Basing dimensions on “D” ensures geometric similarityof hydraulic boundaries and dynamic similarity of flowpatterns. There is some variation in bell velocityamong pump types and manufacturers. However, vari-ations in bell inlet velocity are of secondary impor-tance to maintaining acceleration of the flow andconverging streamlines into the pump bell.

The basic recommended layout for rectangular sumps,dimensioned in units of pump bell diameter “D,” isshown in Figure 9.8.1. The dimension variables andtheir recommended values are defined in Table 9.8.1.

Through-flow traveling screens generally do not clog tothe point where flow disturbances occur. Therefore,they may be located such that Y is 4.0D or more indimension. For non-selfcleaning trash racks or station-ary screens, the dimension Y shall be increased to aminimum of 5.0D. Care must be taken to ensure thatclogging does not occur to the extent that large non-uniformities in the pump approach flow will be generated.



3

The effectiveness of the recommended pump baydimensions depends upon the characteristics of theflow approaching the structure, and upon the geome-try of hydraulic boundaries in the immediate vicinityof the structure. Section 9.8.2.1.1 provides a discus-sion of the requirements for satisfactory approachflow conditions.

Negative values of β (the angle of wall divergence)require flow distribution or straightening devices, andshould be developed with the aid of a physical hydrau-lic model study.

Occasionally, it is necessary to increase the bay widthto greater than 2D to prevent velocities at the entranceto the pump bays from exceeding 0.5 m/s (1.5 ft/s).Greater bay widths may also result due to the arrange-ment of mechanical equipment. In these cases, thebay width in the immediate vicinity of the pumps mustbe decreased to 2D. The dimension of the fillerrequired to achieve the reduction in bay width is asshown in Figure 9.8.2.

For pumps with design flows of 315 l/s (5,000 gpm) orless, no partition walls between pumps are required,and the minimum pump spacing shall be 2D.

Table 9.8.2 provides a sequence of steps to follow indetermining the general layout and internal geometryof a rectangular intake structure.

9.8.2.2 Formed suction intakes

9.8.2.2.1 General

This standard applies to formed suction intakes. Thestandard utilizes the “TYPE 10” design developed bythe US Army Corps of Engineers (ETL No. 110-2-327).The formed suction intake (FSI) may eliminate theneed for the design of sumps with approach channelsand appurtenances to provide satisfactory flow to apump. The FSI design is relatively insensitive to thedirection of approach flow and skewed velocity distri-bution at its entrance. In applying the FSI design, con-sideration should be given to the head loss in the FSIwhich will affect to some extent the system curve cal-culations, and the net positive suction head (NPSH)available to the pump impeller, typically located nearthe FSI exit.

9.8.2.2.2 Dimensions

The FSI design dimensions are indicated in Figure9.8.3. The wall shown in Figure 9.8.3 above the FSI

0 < < 10

CROSS-FLOWVELOCITY, V

PUMP BAY VELOCITY,

0.5 m/s (1.5 ft/s) MAX

OPTIONAL TRAVELING

S

0.3D < C < 0.5D

A > 5D

Z > 5D1

C

VX

B = 0.75D

Y > 4D

Z > 5D2

-10 < < 10

W = 2D

X > 5D

D

H

THROUGH FLOW SCREEN

MIN LIQUID LEVEL

Figure 9.8.1 — Recommended intake structure layout

Figure 9.8.2 — Filler wall details for proper bay width



4

opening reduces the tendency for surface vorticeswhen the FSIs are installed in individual bays. Thewall is not necessary for unrestricted approach flowconditions.

9.8.2.2.3 Application standards

Minimum submergence (see Section 9.8.7) is calcu-lated as follows:

S/D = 1.0 + 2.3 FD

Where:

S is the distance from the minimum recom-mended liquid level to the centerline of theFSI opening in the elevation view

Table 9.8.1 — Recommended dimensions for Figures 9.8.1 and 9.8.2

DimensionVariable Description Recommended Value

A Distance from the pump inlet bell centerline tothe intake structure entrance

A = 5D minimum, assuming no significantcross-flowa at the entrance to the intakestructure

a Cross-flow is considered significant when VC > 0.5 VX average

a Length of constricted bay section near the pumpinlet

a = 2.5D minimum

B Distance from the back wall to the pump inletbell centerline

B = 0.75D

C Distance between the inlet bell and floor C = 0.3D to 0.5D

D Inlet bell design outside diameter See Section 9.8.6

H Minimum liquid depth H = S + C

h Minimum height of constricted bay section nearthe pump inlet bell

h = (greater of H or 2.5D)

S Minimum pump inlet bell submergence S = D(1.0 + 2.3 FD)(see Section 9.8.7 for detailed discussionon determining minimum submergence)

W Pump inlet bay entrance width W = 2D minimum

w Constricted bay width near the pump inlet bell w = 2D

X Pump inlet bay length X = 5D minimum, assuming no significantcross-flow at the entrance to the intakestructure

Y Distance from pump inlet bell centerline to thethrough-flow traveling screen

Y = 4D minimum. Dual-flow screens require amodel study

Z1 Distance from pump inlet bell centerline todiverging walls

Z1 = 5D minimum, assuming no significantcross-flowa at the entrance to the intakestructure

Z2 Distance from inlet bell centerline to slopingfloor

Z2 = 5D minimum

α Angle of floor slope α = –10 to +10 degrees

β Angle of wall convergence β = 0 to +10 degrees(Negative values of β, if used, require flowdistribution devices developed through aphysical model study)

φ Angle of convergence from constricted area tobay walls

φ = 10 degrees maximum



5

D is the diameter of a circle having an areaequivalent to the rectangular FSI opening,D = [(4/π)WHf]

0.5

V used in FD, is the average velocity throughthe FSI opening

9.8.2.3 Circular pump stations (clear liquids)

9.8.2.3.1 General

A circular design is suitable for many types and sizesof pump stations. It can be used with most types ofpumps and for most types of liquids. A circular designmay offer a more compact layout that often results inreduced construction costs.

The circular geometry results in a smaller circumfer-ence, and hence minimizes excavation and construc-tion materials for a given sump volume. The circulargeometry lends itself to the use of the caisson con-struction technique. The availability of prefabricatedcircular construction elements has made this designthe most popular for smaller pump stations. Fullyequipped prefabricated pump stations often have a cir-cular design for the above reasons.

The recommended designs of circular stations are cat-egorized in two groups: duplex and triplex. Stationswith four or more pumps are not addressed in thestandard because of complex flow patterns; suchdesigns require a model study. Circular pump sumpsfor flows exceeding 315 l/s (5000 gpm) per pumprequire a model test.

Table 9.8.2 — Design sequence, rectangular intake structures

DesignStep Description

1 Consider the flow patterns and boundary geometry of the body of liquid from which the pump stationis to receive flow. Compare with the approach flow condition described in Section 9.8.2.1.1 anddetermine from Section 9.8.5.1 if a hydraulic model study is required.

2 Determine the number and size of pumps required to satisfy the range of operating conditions likely tobe encountered.

3 Identify pump inlet bell diameter. If final bell diameter is not available, use the relationship inFigure 9.8.25 to obtain the inlet bell design diameter

4 Determine the bell-floor clearance, see Figure 9.8.1. A good preliminary design number is 0.5D.

5 Determine the required bell submergence, using the relationship in Section 9.8.7.

6 Determine the minimum allowable liquid depth in the intake structure from the sum of the floor clear-ance and the required bell submergence.

7 Check bottom elevation near the entrance to the structure and determine if it is necessary to slope thefloor upstream of the bay entrance.

8 Check the pump bay velocity for the maximum single-pump flow and minimum liquid depth with thebay width set to 2D. If bay velocity exceeds 0.5 m/s (1.5 ft/s), then increase the bay width to reduceto a maximum flow velocity of 0.5 m/s (1.5 ft/s).

9 If it is necessary to increase the pump bay width to greater than 2D, then decrease bay width in thevicinity of the pumps according to Figure 9.8.2.

10 Compare cross-flow velocity (at maximum system flow) to average pump bay velocity. If cross-flowvalue exceeds 50% of the bay velocity, a hydraulic model study is necessary.

11 Determine the length of the structure and dividing walls, giving consideration to minimum allowabledistances to a sloping floor, screening equipment, and length of dividing walls. If dual flow travelingscreens or drum screens are to be used, a hydraulic model study is required (see Section 9.8.5.1,Need for Model Study).

12 If the final selected pump bell diameter and inlet velocity is within the range given in Section 9.8.6, thesump dimensions (developed based on the inlet bell design diameter) need not be changed andwill comply with these standards.



6

9.8.2.3.2 Recommendations for dimensioning circular pump stations

9.8.2.3.2.1 Nomenclature

Cf = Floor clearance

Cw = Wall clearance

Cb = Inlet bell or volute clearance (asapplicable)

Ds = Sump diameter

Db = Inlet bell or volute diameter (as applicable)

S = Submergence, the vertical distance fromminimum sump liquid level to pump inlet,usually pump inlet bell (see Section 9.8.7for details).

9.8.2.3.2.2 Floor clearance Cf

The floor clearance should not be greater than neces-sary, because excessive floor clearance increases theoccurrence of stagnant zones as well as the sumpdepth at a given submergence. The conditions thatdetermine the minimum floor clearance (Cf) are therisk of increasing inlet head loss and flow separation atthe bell. Submerged vortices are also sensitive to floorclearance. Recommended floor clearance is between0.3D and 0.5D.

9.8.2.3.2.3 Wall clearance Cw

The minimum clearance between an inlet bell or apump volute and a sump wall is 0.25D or at least100 mm (4 inches).

Figure 9.8.3 — Type 10 formed suction intake



7

9.8.2.3.2.4 Inlet bell clearance Cb

The minimum clearance between adjacent inlet bellsor volutes (as applicable) is 0.25D or at least 100 mm(4 inches).

9.8.2.3.2.5 Sump diameter Ds

Minimum sump diameter shall be as indicated for eachtype of pump sump as shown in Figures 9.8.4Athrough 9.8.5C.

9.8.2.3.2.6 Inlet bell or volute diameter Db

This parameter is given by the proposed pump typeand model.

For submersible and other pumps with a volute in thewet pit, use the volute diameter.

For pumps without a volute in the wet pit, use the inletbell diameter.

9.8.2.3.2.7 Inflow pipe

The inflow pipe shall not be placed at an elevationhigher than that shown in the figures. This placement

minimizes air entrainment for liquid cascading downinto the sump from an elevated inflow pipe. It is impor-tant to position the inflow pipe(s) radially and normal tothe pumps, as shown in the figures, to minimize rota-tional flow patterns. For the last five pipe diametersbefore entering the sump, the inflow pipe(s) shall bestraight and have no valves or fittings.

9.8.2.4 Trench-type intakes (clear liquids)

This section establishes criteria for design of trench-type wet wells using both formed suction and bell-typepump inlets for clear liquid applications.

9.8.2.4.1 General

Trench-type wet wells differ from rectangular intakestructures (see Section 9.8.2.1) by the geometry usedto form a transition between the dimensions of theinfluent conduit or channel and the wet well itself. Asillustrated in Figures 9.8.6 and 9.8.7, an abrupt transi-tion is used to create a confined trench for the locationof the pump inlets.

While only limited modeling work has been conductedon trench-type wet wells, successful applications withindividual pump capacities as great as 4730 l/s

D

D

C

D

C

C

C

C /2

C /2D

C

s sD

f fCfC

Ds

w

Cw

b

b

b

w wC

b

b

b

bb C /2b

bC

bD

< D /2

S S

S

D = 2.5 D + 2 C + Cbwbs min minsD bb w= 2 D + 2 C + C

D by pit designs

Figure 9.8.4A — Wet pit duplex sump with pumps offset

Figure 9.8.4B — Wet pit duplex sump with pumps centerline

Figure 9.8.4C — Dry pit/wet pit duplex sump



8

(75,000 gpm) and installation capacities of 14,200 l/s(225,000 gpm) have been constructed for centrifugalpumps. Axial and mixed flow applications of thetrench-type wet well include individual pump capaci-ties of 2900 l/s (46,000 gpm) and total installationcapacities of up to 12,000 l/s (190,000 gpm). Most

applications of the trench-type design have been withthe incoming flow directed along the wet well's longaxis (coaxial). Model studies shall be conducted forany installation with individual pump capacitiesexceeding 2520 l/s (40,000 gpm) or stations withcapacities greater than 6310 l/s (100,000 gpm).

D

C

Ds

fC

sD

Cf

sD

wCCf

Cw

b

b

Cw

Cw

D b

D b

Cb

bCbC /2

SSS

D = 3 D + 2 C + Cbwbs min minsD bb w= 2 (D + 2 C + C ) D by pit designs

Figure 9.8.5A — Wet pit triplex sump, pumps in line

Figure 9.8.5B — Wet pit triplex sump, compact

Figure 9.8.5C — Dry pit/wet pit triplex sump

Figure 9.8.6 — Trench-type wet well



9

9.8.2.4.2 Objectives

The purpose of the trench-type wet well is to shield thepump intakes from the influence of the concentratedinflow. The shielding is accomplished by locating theinlets well below the invert elevation of the influentchannel or conduit.

9.8.2.4.3 Orientation

It is preferable to align the long axis of the wet well withthe centerline of the upstream conduit or channel. Off-set centerlines are not recommended. The approachconduit can be normal to the axis of the trench as longas careful attention is given to the approach velocity.The approach velocity is limited for each orientation.See Section 9.8.2.4.4.

9.8.2.4.4 Approach velocity

The velocity in the approach channel or conduit,upstream from the wet well, shall be no greater than1.2 m/s (4.0 ft/s) with the axis of the channel or conduitcoaxial with the axis of the wet well. If the axis of thechannel or conduit is normal to the axis of thetrench, a maximum velocity of 0.6 m/s (2.0 ft/s) isrecommended.

9.8.2.4.5 Width

The recommended width of the bottom of the trenchfor trench-type wet wells is twice the diameter of thepump intake bell. The width of the sump above thetrench must be expanded to produce an average limit-ing velocity in the trapezoidal area above the trench of0.3 m/s (1.0 ft/s). See Figure 9.8.6.

9.8.2.4.6 Intake submergence

See Submergence, Section 9.8.7

9.8.2.4.7 End wall clearance

Clearance between the centerline of the intake belland the end walls of the trench should be 0.75D.

9.8.2.4.8 Floor clearance

Clearance between the floor of the trench and the rimof the inlet bell shall be 0.3D to 0.5D. Floor cones arerecommended under each of the pump inlet bells. SeeParagraph 9.8.3.2.3.2 for solids-bearing liquids.

9.8.2.4.9 Centerline spacing

Centerline spacing of adjacent intake bells shall be noless than 2.5D.

9.8.2.4.10 Inlet conduit elevation

The elevation of the incoming conduit shall beadjusted so that a cascade is avoided at the minimumliquid level.

9.8.2.5 Suction tanks

9.8.2.5.1 General

This standard applies to partly filled tanks, pressurizedor non-pressurized, handling non-solids bearing liquidswhere the outflow occurs with or without simultaneousinflow. The following design features are considered:

Tank GeometryVertical CylindricalHorizontal CylindricalRectangular

Outlet Orientation and LocationVertical, DownwardsHorizontal, SideHorizontal, BottomVertical, Upwards

Formed suction inlet (FSI)SECTION See 9.8.2.2 for FSI dimensions

Formed suction

trench = 0.3 m/s

Max velocity inchannel above

or conduitInfluent pipe

Min liquid level

Cross-sectional area

entrance areaEqual to FSI

PLAN

Liquid surfacevariation

W

1.5 W

H

HS

H /2

f

ff

inlet, typ.

(1 ft/s)

Figure 9.8.7 — Trench-type wet well with formed suction inlet



10

Outlet ConfigurationFlush With Tank Interior SurfaceProtruding Through Tank Interior Surface

Outlet FittingStraightConeBell


The purpose of this standard is to recommend fea-tures of tank connections to minimize air or gasentrainment during the pumping process. It isassumed that the pump is far enough downstreamof the tank outlet, such that flow irregularities aredissipated.

9.8.2.5.3 Discussion

Due to the formation of vortices inside the tank, air orgas entrainment can occur in pump suction tanks,even when the tank outlet is totally submerged. Severecases of air entrainment can cause erratic or noisypump operation or reduction in pump performance. Apump is affected by entrained air that can collect, andin severe cases, block the impeller eye and cause lossof prime.

The extent of air entrainment, caused by vortex forma-tion in a suction tank, depends on the vortex strength,submergence of the tank outlet, and the fluid velocityin the tank outlet. Vortices may occur in tanks undervacuum or pressure, whether or not the level is varyingor steady due to inflow.

9.8.2.5.4 Principles

See Figure 9.8.8, examples 1 through 4. The recom-mended minimum submergence S of the outlet fittingbelow the free surface of the liquid within the tank toprevent air core vortices, given tank outlet diameter D,may be obtained from the relationship

S/D = 1.0 + 2.3 FD

Where:

FD = Froude number = V/ (gD)0.5

D = outlet fitting diameter

V = outlet fitting velocity

g = acceleration of gravity

For further discussion of submergence, see Section 9.8.7

9.8.2.5.5 Application options

Whereas Figure 9.8.8, examples 1 through 4 showhow the calculated submergence value is to beapplied, Figure 9.8.9, examples 5 through 8 showwhere values of V and D are obtained for the threetypes of outlet fitting designs: straight, cone-shaped,and bell-shaped. If the desired minimum submergenceis less than that calculated by the above relationship,the outlet size, and therefore fluid velocity, may beadjusted to reduce the required minimum submer-gence. It may be desirable to use a bell-shaped orcone-shaped fitting to reduce the head loss in the fit-ting. In such cases, shown in Figure 9.8.9, examples 5through 8, the largest diameter of the fitting is used inthe above equations to calculate velocity, V. Owing tothe uncertain approach conditions typically encoun-tered in a closed tank or vessel, outlet vortex breakersas illustrated in Appendix A, Figure A.12, should beconsidered.

Figure 9.8.8 — Datum for calculation of submergence



11

9.8.2.5.6 NPSH considerations

All the head losses incurred from the free liquid sur-face to the pump inlet must be considered when calcu-lating the NPSH available for the pump.

9.8.2.5.7 Simultaneous inflow and outflow

In general, tanks should not have the inlet pipe closeto the tank outlet when inflow and outflow occur simul-taneously. Suitable baffling or other flow distributiondevices may be required to isolate the outlet or reducethe inlet effects on flow patterns. Special attentionshould also be given to the design to avoid air entrain-ment with a non-submerged inlet pipe.

9.8.2.5.8 Multiple Inlets or Outlets

The design of tanks with multiple inlets and/or outletsshould be such that unsatisfactory flow interactiondoes not occur. Baffling or other flow distributiondevices may be required to eliminate such effects.

9.8.2.6 Can and submersible vertical turbine pump intakes (clear liquids)

9.8.2.6.1 General

A can pump is a pump that has a barrel around thepumping unit.

The purpose of this section is to establish criteria forthe design of clear liquid intakes for open bottom andclosed bottom can vertical turbine pumps as well as forsubmersible (well motor driven) vertical turbinepumps. It is necessary to avoid designs to simply fitinto a piping arrangement without considering flowpatterns to the can inlet or in the barrel itself. For sub-mersible vertical turbine pumps, the cooling of theimmersed motor must also be considered.

The intake design information provided is for verticalturbine type pumps less than 5000 specific speed (USunits). Higher specific speed vertical mixed flow andpropeller pumps may perform in a barrel; however;they are more sensitive to hydraulic suction design.Refer to the pump manufacturer for specific can intakedesigns for these pumps.

9.8.2.6.2 Objective

The following provides guidelines to avoid unfavorableflow conditions for both open bottom and closed bot-tom vertical turbine can pump intakes.

9.8.2.6.3 Design considerations

It is necessary to design the can intake such that thefirst stage impeller suction bell inflow velocity profile isuniform. An asymmetrical velocity profile may result inhydraulic disturbances, such as swirling, submergedvortices and cavitation, that may result in performancedegradation and accelerated pump wear.

It is recommended that the vertical pump be allowed tohang freely suspended and without restraining attach-ments to its vertical pump can (riser). However, if it isnecessary to install restraining attachments betweenthe pump and barrel, such as for seismic compliance,binding of the pump must be avoided.

The pump manufacturer should be consulted regard-ing the design of any component that affects the pumphydraulic intake performance. These include thesuction barrel, 90° turning vane elbow and vortexsuppressor.

Direction ofTank Outlet

5) Vertically Downwards (Bottom) Outlet

6) Horizontal, (Side) Outlet

7) Horizontal, (Bottom) Outlet

8) Vertically Upwards

a) Straight

V

D

V

D

V

DV

DV

D

VD

V

D

V

D

b) Cone c) Bell

Type of Outlet Fitting(Straight, Cone, or Bell)

V

D

V

D

V D

V D

V D

V

D

V

D

V

D

V

D

EccentricReducer

Figure 9.8.9 — Definitions of V and D for calculation of submergence



12

9.8.2.6.4 Open bottom can intakes (Figure 9.8.10)

The minimum liquid level is considered a minimumoperational level. When the pump is started, the mini-mum liquid level will reduce momentarily until thepump flow velocity is achieved. The intake piping mustbe large enough to limit draw down below the recom-mended minimum suction level to a period of less than3 seconds during start-up.

Open bottom can intakes with flows greater than 315 l/s(5000 gpm) per pump require a model test.

Example 1 - This pump intake configuration is particu-larly effective when liquid elevations (pump submer-gence) is limited. Flows through a horizontal suctionheader with velocities up to 2.4 m/s (8.0 ft/s) can beeffectively directed into a vertical turbine pump by useof a 90° vaned elbow. Intake model tests for pumpflows above 315 l/s (5000 gpm) are recommended.

The 90° turning vane inlet diameter (D) shall be sizedto limit the inflow velocity to 1.5 m/s (5.0 ft/s). Attach-ment of a 90° vaned elbow to the horizontal header isrecommended to provide hydraulic thrust restraint.Caution is necessary when using this intake configura-tion in liquids containing trash or crustaceans thatattach to the turning vanes.

Example 2 - The vortex suppressor and pump are anintegral assembly which can be removed for repair,cleaning and inspection. A vortex suppressor is neces-sary to break up abnormal flow patterns ahead of thepump suction bell. For vertical turbine pumps withrated flows less than 315 l/s (5000 gpm) the maximumhorizontal header velocity is 1.8 m/s (6.0 ft/s) and themaximum riser velocity is 1.5 m/s (5.0 ft/s). The instal-lation must allow the pump to hang centered in the ver-tical riser pipe.

V (Header) < 2.4 m/s

MIN. LIQUID LEVELD 1

11.0 D

C 1st. IMPELLERL

90 TURNINGVANE ELBOW

VERTICAL CAN(RISER)

HORIZONTAL HEADER

EXAMPLE-1 EXAMPLE-2

HORIZONTAL HEADER

V (Header) < 1.8 m/s (6 ft/s)

1DMIN. LIQUID LEVEL

C 1st. IMPELLERL

11.0 D

(RISER)VERTICAL CAN

3.0 D1MIN.

VORTEXSUPPRESOR

DMIN. LIQUID LEVEL

EXAMPLE-3

1

1.0 D

VANE ELBOW90 TURNING

(RISER)VERTICAL CAN

C 1st. IMPELLERL

1

TURBINE PUMPBOWL ASSEMBLY

TO RESTRAIN 90THRUST BLOCK

ELBOW MAY BENECESSARY

FLEXIBLE CONNECTORWITH HARNESED TIE

DRY PIT APPLICATION"O"RING OR GASKET

EXAMPLE-4

D

90 LONG RADIUSELBOW

OPTIONAL STRAIGHTENINGVANES ALLOWS VELOCITYINCREASE TO 1.5 m/s (5 ft/s)

(2 ft/s)

JOINTS TO PREVENTLEAKAGE.

TURBINE PUMPBOWL ASSEMBLY

BOLTS.

BOWL ASSEMBLYTURBINE PUMP

BOWL ASSEMBLYTURBINE PUMP

SUCTION HEADER END DRY PIT5D MINIMUM

STRAIGHT PIPE

V (Turning Vane) < 1.5 m/s (5 ft/s)

V (Riser) < 1.5 m/s (5 ft/s)

V < 0.6 m/s

(8 ft/s)

V (Turning Vane) < 1.5 m/s (5 ft/s)

Figure 9.8.10 — Open bottom can intakes (pumps less than 315 l/s [5000 gpm])



13

Example 3 - When the vertical riser is located at theend of a suction header, a 90° vaned elbow must beused to direct flow into the pumps suction. This intakeconfiguration is effective when liquid elevation (pumpsubmergence) is limited. The 90° turning vane inletdiameter (D) shall be sized to limit the inflow velocity to1.5 m/s (5.0 ft/s).

Example 4 - A 90° long radius elbow may be used atthe end of a suction header to direct flow into thepump suction when velocities are less than 0.6 m/s(2.0 ft/s). Installing vanes in the elbow (although diffi-cult) promotes a uniform velocity flow profile. Velocitiesup to 1.5 m/s (5.0 ft/s) are acceptable when the elbowis fully vaned.

A flexible joint between the pump suction and theelbow is recommended to isolate the pump from pipingloads. Because this is a dry pit application, the jointsthroughout the pump should be sealed against leak-age by the use of “O” rings, gaskets, etc.

9.8.2.6.5 Closed bottom can

The most typical can pump configurations are closedbottom. See Figure 9.8.11 for design recommenda-tions with various inlet pipe positions relative to thebell.

Centering of the pump in relation to the can to avoidrotational flow being generated by non-uniform flowaround a non-concentric pump is of particular impor-tance. Care must be taken during installation of the

Figure 9.8.11 — Closed bottom can



14

barrel to assure concentricity of pump to barrel. Flowstraightening vanes are suggested for all can intakesand shall be provided for pump capacities greater than189 l/s (3000 gpm). A pair of vanes should be cen-tered on the inlet to the barrel and extended to abovethe normal liquid level or to the top of the barrel, asapplicable. The vanes should protrude as far as practi-cal into the barrel. A set of vanes in the form of a crossshould be provided under the pump bell. In someapplications, the pump manufacturer may wish to useother methods to prevent swirling.

Because of the limited volume provided by a can typeintake, surging of the liquid level within the barrel maybe a problem when operating with a partially filled can.

The intake piping must be large enough to limit drawdown below the recommended minimum liquid level toa period of less than 3 seconds during start-up.

9.8.2.6.6 Submersible pumps (well motor type)

Design criteria is provided for both wet pit type andclosed bottom can below grade suction intakes.Proper placement of this type of submersible pump ina well is beyond the scope of this standard.

A submersible well type motor normally requires aminimum flow of liquid around the immersed motor to

provide for adequate motor cooling. For many applica-tions a shroud is required to assure proper coolingflow around the motor. Sizing of the cooling shroud forinternal flow velocities must be referred to the pumpmanufacturer. The top of the shroud must include acover to restrict downward flow of liquid, while allowingfor venting of air from the shroud.

The intake piping must be large enough to limit drawdown below the recommended minimum liquid level toa period of less than 3 seconds during start-up.

The first stage impeller is located above both thestrainer and motor. A suction case is located below thefirst stage impeller. The confined flow pathway pro-vided by the motor cooling shroud is very desirable indeveloping a uniform flow to the first stage impeller.Therefore, placement of the wet pit type submersibleper Section 9.8.2.1 is only necessary for flow ratesabove 315 l/s (5000 gpm).

9.8.2.7 Unconfined intakes

9.8.2.7.1 Scope

Unconfined intakes involve pumps installed on plat-forms or other structures where the intake lacks guidewalls, walls of a sump or other flow guiding structures.Typical installations include intakes on rivers, canals or

Figure 9.8.12 — Submersible vertical turbine pump



15

channels, intakes on lakes and pumps located on plat-forms for seawater systems.

9.8.2.7.2 Cross-flow velocities and pump location

Pumps with unconfined intakes are often locatedwhere a unidirectional cross-flow occurs, or on plat-forms where tidal variations may cause highly complexcurrent conditions around the pump inlet bell. Theminimum recommended distance from an obstructionto the pump suction in the direction of any current thatcould cause wake effects is five times the maximumcross-sectional dimension of the obstruction.

Cross-flow velocities shall be less than 25% of the bellvelocity, but the designer may have little control overthis variable. Installations with higher cross-flow veloc-ities require special flow correction devices which arebeyond this design standard (see Appendix A for refer-ence information). For higher cross-flow velocities,supplemental lateral support of the pump may berequired.

If debris or bottom sediments are not a problem, theinlet bell shall be located 0.3 to 0.5 D above the bottomto minimize submerged vortices. For applicationswhere suspension of bottom debris may be a problem,a 5D minimum clearance is suggested.

For installations on platforms along the seashore, sus-pension of sand during storms is unavoidable due towave action. In some cases, a bed of armor stonearound the intake has proved useful in minimizing sus-pension of sediments. The design of such armor lay-ers should be performed with the assistance of anengineer with experience in sediment transport anddesign of riprap protection, as the proper design ofarmor stone protection requires specialized techniques.

9.8.2.7.3 Debris and screens

Debris is of particular concern for unconfined intakes.Light debris loading may be accommodated byscreens attached to the pump bell. Special designconsiderations are required to accommodate heavydebris loading.

Large floating debris and ice which could damage thepump is also of concern. A barrier may be required toprotect the pump. These barriers should not introducewake disturbances into the pump.

9.8.2.7.4 Submergence

S/D = 1.0 + 2.3 FD

Where:

FD = Froude number = V/(gD)0.5

D = outlet fitting diameter

V = outlet fitting velocity

For further discussion of submergence, see Section 9.8.7.

9.8.3 Intake structures for solids-bearing liquids

9.8.3.1 General

Wet wells for solids-bearing liquids require specialconsiderations to allow for the removal of floating andsettling solids. These considerations include wet wellgeometry and provisions for cleaning of the structureto remove material that would otherwise be trappedand result in undesirable conditions.

9.8.3.1.1 Scope

This standard applies specifically to installationswhere the pumped liquid contains solids that may floator settle in the wet well. Fluids such as wastewater,industrial discharges, storm or canal drainage, com-bined wastewater, and some raw water supplies areincluded in this category.


The objective of this standard is to introduce specialdesign features recommended for wet wells used insolids-bearing liquid applications. These features areintended to eliminate or minimize accumulations ofsolids, thereby reducing maintenance. Organic solidsaccumulations not removed may become septic, caus-ing odors, increasing corrosion, and releasing hazard-ous gases.

9.8.3.1.3 Principles

The main principle is to minimize horizontal surfaces inthe wet well anywhere but directly within the influenceof the pump inlets, thereby directing all solids to alocation where they may be removed by the pumpingequipment. Vertical or steeply sloped sides shall beprovided for the transition from upstream conduits orchannels to pump inlets. Trench-type wet wells (seeSection 9.8.2.4) and circular plan wet wells (see Sec-tion 9.8.2.3), with some modifications as presented inthis section, have been found to be suitable for thispurpose.



16

9.8.3.1.4 Vertical transitions

Transitions between levels in wet wells for solids-bearing liquids shall be at steep angles (60° minimumfor concrete, 45° minimum for smooth-surfaced materi-als such as plastic and coated concrete—all anglesrelative to horizontal) to prevent solids accumulationsand promote movement of the material to a locationwithin the influence of the currents entering the pumpintakes. Horizontal surfaces should be eliminatedwhere possible except near the pump inlet. See Fig-ures 9.8.13 and 9.8.14.

9.8.3.1.5 Confined inlet

The horizontal surface immediately in front (for formedsuction inlets) or below (for bell inlets) should be lim-ited to a small, confined space directly in front of orbelow the inlet itself. To make cleaning more effective,the walls and floor forming the space must be confinedso that currents can sweep floating and settled solidsto the pump inlet. See Figure 9.8.17.

Transition from circular to rectangularrecommended, see Section 9.8.3.2.1

Anti-rotation baffle (protudeas far as practical)

0.3 m/s (1.0 ft/s) maxvelocity above trench

2D min

ε

D

2D

SECTION A-A

≥ 2.33 head on sluice gate (2D min)ε ≥ 45° for smooth surface (plastic lining)ε ≥ 60° for concreteS ≥ (1 + 2.3FD)D

LONGITUDINAL SECTION

Hydro cone

D/4D/2

A

Vane

S

0.5to

1.0

Min level

Sluice gate4 ft/s max

A

PLAND

0.75 D

2.5 Dmin.

Figure 9.8.13 — Open trench-type wet well

SECTION A-AA

A

D/42 D

MIN LEVEL

Figure 9.8.14 — Open trench-type wet well for pumps sensitive to loss of prime



17

9.8.3.1.6 Cleaning procedures

Removal of solids from wet wells, designed in accor-dance with these principles, can be achieved by oper-ating the pumps selectively to lower the level in the wetwell until the pumps lose prime. Both settled and float-ing solids are removed by the pumping equipment anddischarged to the force main (or discharge conduit).This cleaning procedure momentarily subjects thepumps to vibration, dry running, and other severe con-ditions. Consult the pump manufacturer before select-ing the pumping equipment. The frequency of cleaningcycles is dependent on local conditions, and thereforeshould be determined by experience at the site.

Alternatively, liquid jets or mixers positioned to createhorizontal and vertical currents, can be used intermit-tently or continuously to maintain suspension anddirect floating and settled solids toward the pumpintakes. The solids are swept into the pump intake forremoval. Caution should be exercised, when using jetsor mixers, to avoid inducing continuous currents nearpump inlets that could result in damage to the pump-ing equipment.

9.8.3.1.7 Wet well volume

Wet wells for variable speed pumping stationsdesigned to match outflow with inflow need not bedesigned for storage, but rather only to accommodatethe inlets and the geometry required for velocity limita-tions and cleaning.

Wet wells for constant speed pumps should be con-structed to minimize size for economy and to facilitatecleaning. One approach is to provide storage for pumpregulation in the upstream conduit or channel, as wellas in the wet well itself. Refer to Appendix B for guid-ance on sump volume for constant speed pumps andAppendix C for storage in the upstream conduit.

9.8.3.2 Trench-type wet wells for solids-bearing liquids

9.8.3.2.1 General

The purpose of this section is to establish criteria fordesign of trench-type wet wells for solids-bearing liq-uids such as stormwater, wastewater, and canal-typepumping stations.


Trench-type wet wells have been successfullydesigned to provide for cleaning with the periodic

operation of the pumping equipment using a specialprocedure. This standard provides guidance on thegeometry necessary to induce scouring velocities dur-ing the cleaning procedure. Experience has shownthat trench-type wet wells with an ogee transitionbetween the entrance conduit and the trench floorprovides optimum geometry for efficient cleaningoperations.

Refer to Sections 9.8.3.2.3 to 9.8.3.2.5 and Figure9.8.13 for recommendations for trench-type wet wells.Trench-type wet wells can be used with both constantspeed and variable speed pumping equipment.

There is no difference between wet wells for variableas compared with constant speed pumps, but there isa difference between inlet conduits for the two kinds ofpumping stations. With variable speed pumps, there isno need for storage, because pump discharge equalsinflow. Consequently, the water level in the wet wellcan be made to match the water level in the upstreamconduit.

When constant speed pumps are used, the water levelmust fluctuate — rising when pumps are off and fallingwhen they are running. There must be sufficient activestorage to prevent excessive frequency of motorstarts. As trench-type wet wells are inherently smalland not easily adapted to contain large volumes ofactive storage, it is desirable to dedicate a portion ofthe upstream conduit to storage. The dedicated por-tion is called an “approach pipe.” It is usually 75 to 150mm (3 to 6 inches) larger than the conduit upstream ofthe dedicated portion, and it is laid at a compromisegradient of 2% (although other gradients could beused.) At low water level, the velocity in the approachpipe is supercritical, thus leaving a large part of thecross section empty for storage as the water levelrises. The design of approach pipes is not a part ofthese standards, but the essentials of design are givenin Appendix C.

9.8.3.2.3 Open trench design

See Figure 9.8.13 for the arrangement of an opentrench wet well.

9.8.3.2.3.1 Inlet transition

The ogee spillway transition at the inlet to the wet welltrench is designed to convert potential energy in theinfluent liquid to kinetic energy during the wet wellcleaning cycle. The curvature at the top of the spillwayshould follow the trajectory of a free, horizontal jetissuing from under the sluice gate and discharging



18

approximately 75% of the flow rate of the last pump.The radius of the curvature, r, shall be at least 2.3times the pressure head upstream of the sluice gateduring cleaning. The radius of curvature at the bottomof the ogee need be large enough only for a smoothtransition to horizontal flow; 0.5 r to 1.0 r is sufficient.

To produce smooth flow down the ogee ramp andavoid standing waves, the discharge under the sluicegate should be uniform in depth across the 2D width ofthe trench. Either (1) a short transition from a circularto a rectangular section, as shown in Figure 9.8.13 or(2) a short rectangular recess in front of the sluice gateis recommended.

9.8.3.2.3.2 Inlet floor clearance

All bell-type pump inlets, except that farthest from thewet well inlet, shall be located D/2 above the floor ofthe wet well trench. The inlet for the last pump (far-thest from the wet well inlet) shall be located D/4above the floor of the trench. See Figure 9.8.13.

For pumps that may be sensitive to loss of prime (dueto entrainment of air from surface vortices), the lastpump inlet can be lowered by D/4 provided the floornear the intake is lowered by the same amount. SeeFigure 9.8.14 for this arrangement. All other dimen-sions and velocities for this arrangement shall complywith those given in Figure 9.8.13.

9.8.3.2.3.3 Inlet splitters and cones

Fin-type floor splitters aligned with the axis of thetrench are recommended. They must be centeredunder the suction bells for all but the pump inlet far-thest from the wet well entrance. A floor cone shouldbe installed under the pump inlet farthest from the wetwell inlet conduit or pipe as shown in Figure 9.8.13.

9.8.3.2.3.4 Anti-rotation baffle

An anti-rotation baffle at the last pump inlet, shown inFigure 9.8.13, is needed to ensure satisfactory perfor-mance during the cleaning cycle. The anti-rotation baf-fle should protrude towards the pump as far aspracticable.

9.8.3.2.3.5 Cleaning procedure

Trench-type wet wells for solids-bearing liquids can becleaned readily by stopping all pumps to store enoughliquid for the cleaning process in the upstream conduit.When sufficient liquid is available, flow into the wetwell should be limited to approximately 75 percent of

the flow rate of the last pump in the trench by adjustingthe sluice gate. The pumps are operated to lower theliquid level to a minimum as rapidly as possible suchthat the stored liquid volume is sufficient to completethe cleaning cycle. As the liquid level in the wet wellfalls, the liquid attains supercritical velocity as it flowsdown the ogee spillway, and a hydraulic jump isformed at the toe. As the hydraulic jump moves alongthe bottom of the trench, the jump and the swift cur-rents suspend the settled solids, causing them to bepumped from the trench. As the hydraulic jump passesunder each pump intake, the pump loses prime andshould be stopped.

9.8.3.3 Circular plan wet pit for solids-bearing liquids

9.8.3.3.1 Wet pit design

The design of the wet pit should adhere to the generalrecommendations given in Section 9.8.2.3. Addition-ally, the bottom of the wet pit shall have sloped sur-faces around the inlet bells or pumps, as shown inFigures 9.8.15 and 9.8.16.

9.8.3.3.2 Accessories

The use of pump and sump accessories that causecollection or entrapment of solids should be limited toa practical minimum.

Figure 9.8.15 — Circular wet pit with sloping walls and minimized horizontal floor area (submersible

pumps shown for illustration)



19

9.8.3.3.3 Cleaning procedure

The frequency of cleaning cycles is dependent onlocal conditions, and therefore should be determinedby experience at the site. Removal of settled solids iseffected each time a pump is activated, but removal offloating solids can only be accomplished when the liq-uid surface area is at a minimum and the pump intakesubmergence is low enough (0.5 to 1.0 D) to create astrong surface vortex (number 4 to number 6 in Figure9.8.23). Such a submergence level is lower than thatrecommended in Section 9.8.7. Pumping under thesesevere conditions will cause noise, vibration, and highloads on the impeller and hence should be limited tobrief, infrequent periods (refer to pump manufacturer’srecommendation). The pumps should be stopped assoon as they lose prime, or as soon as the sump isfree of floating debris.

9.8.3.4 Rectangular wet wells for solids-bearing liquids

9.8.3.4.1 General

The geometry of rectangular wet wells is not particu-larly suited for use with solids-bearing liquids, but withspecial provisions for frequent cleaning, such wetwells may be acceptable.


The objective of this section is to describe severalmeans for minimizing or eliminating accumulations ofsolids before they interfere with the operation of thepumps or before they become septic and generateexcessive odors that must be treated.

9.8.3.4.3 Control of sediments

Several means for controlling the accumulation of sed-iments are possible, such as:

• Designing the wet well to provide currents swiftenough (e.g., 1.0 m/s [3.0 ft/s] or more) to carrysettleable solids to the pump intakes. Such ameans should be thoroughly investigated before adesign is begun.

• Violent mixing to suspend sediments while themixture is being removed by the main pumps.These methods include:

1) Use of submerged mixers.

2) Bypassing part of the pump discharge backinto the wet well.

3) Connecting the force main to a valve and thento the wet well. About half of the pump dis-charge is allowed to recirculate back into thewet well.

• Dewatering the wet well and sweeping solids tothe pumps with a high-pressure hose.

• Vacuuming both floating and settled solids out ofthe wet well, usually by an external pump andhose.

• Dewatering one side of the wet well (if possible)and removing the solids.

9.8.3.4.4 Confined wet well design

In this arrangement each suction inlet bell is located ina confined pocket to isolate the pump from any flowdisturbances that might be generated by adjacentpumps, to restrict the area in which solids can settle,and to maintain higher velocities at the suction inlet inorder to minimize the amount of solids settling out ofthe flow.

See Figure 9.8.17 for the arrangement of a confinedwet well.

Figure 9.8.16 — Circular wet pit with sloping walls and minimized horizontal floor area (dry

pit pumps)



20

9.8.3.4.4.1 Suction inlet clearance

All suction inlets shall be located D/4 above the floor ofthe wet well. The side walls of the individual cellshould be 1.5 to 2.0 D in dimension. The depth of theindividual cell must be a minimum of 2.0 D square. Acone shall be installed under each suction inlet.

9.8.3.4.4.2 Anti-rotation baffle

Anti-rotation baffles are required for individual flows inexcess of 189 l/s (3000 gpm).

9.8.3.4.4.3 Cleaning procedure

Removal of settled solids from wet wells, designed inaccordance with the Figure 9.8.17, can be achieved byoperating the pumps one at a time at full speed for aduration of about two minutes. Typically, only onepump should be operated at a time to avoid excessivedraw down of the liquid level in the sump.

The majority of floating solids are removed from thesump by operating the pumps one at a time at fullspeed while restricting the flow into the wet well to 80to 60 percent of the flow rate of the pump at full speed.Adjusting the sluice gate is the normal method of flow

restriction. As the liquid level in the wet well falls, swiftcurrents will suspend most of the floating debris, caus-ing them to be pumped from the trench. The pumpwill eventually lose prime and must be stoppedimmediately.

Both settled and floating solids are removed by thepumping equipment and discharged to the force main(or discharge conduit). This cleaning proceduremomentarily subjects the pumps to vibration, dry run-ning, and other severe conditions. The frequency ofcleaning cycles is dependent on local conditions, andtherefore should be determined by experience at thesite. Generally, the cleaning operation will take lessthan 5 minutes to perform and the duration betweencleaning cycles would typically be 1 to 2 weeks.

9.8.4 Pump suction piping

9.8.4.1 General

This section provides information and design recom-mendations for suction piping, required for all pumpingapplications, except where the pump inlet is immersedin the liquid. Proper design of suction piping is criticalin that it determines the uniformity of flow delivered tothe pump. Disturbed inflow causes deterioration ofpump performance and may shorten pump life due tovibration and cavitation. Discharge piping has virtuallyno effect on pump performance other than the headloss that it creates. In this section, the term “pipe fit-tings” refers to all types of plumbing fittings, such asbends, reducers, tee and wye connections, and alltypes of valves.

This standard is intended to provide design recom-mendations such that the pump will receive inflow ofsufficient uniformity to perform its intended duty. Otherpiping considerations, such as head loss, materialselection, costs, and space requirements also need tobe considered and are not covered here.

9.8.4.2 Principles

The ideal flow entering the pump inlet should be of auniform velocity distribution without rotation and stableover time. This ideal flow is often referred to as undis-turbed flow, and it can be achieved by controlling pipelengths and the type and location of fittings in the suc-tion piping system. The suction piping should bedesigned such that it is simple with gentle transitions ifchanging pipe sizes. Transitions resulting in flow decel-eration at the pump shall not used.

Section

45 Min.

PLAN

Pump inlet located in a confinedpocket at least 1.5 bell diametersbut no more than 2 bell diametersin plan in any direction

D/4

Vertical or steep slopesto pump inlet pipecovered with PVC

Cone

Greater of

>2D

1.5-2.0 D

D

1.5-2.0 D

(2.0 ft/s max)

4D or S

0.6 m/s max

Anti-Rotation Baffle

Figure 9.8.17 — Confined wet wall design



21

The velocities recommended in Section 9.8.4.3 shallbe adhered to while keeping in mind that higher veloc-ities increase head loss and thus decrease the NPSHavailable at the pump inlet.

The effect of disturbed flow conditions at the inlet bell,i.e., at the beginning of the suction piping, tend todiminish with distance. Short suction piping is lesseffective in moderating disturbances before the flowreaches the pump. Good inflow conditions at the inletbell exists if the intake is designed following recom-mendations in other parts of this standard. See Figure9.8.18. The recommended inlet bell velocity is speci-fied in Table 9.8.3.

Part of the suction piping system can be subjected topressures below atmospheric. It is, therefore, impor-tant to ensure that all fitting joints are tight, because airentrainment on the suction side may cause a reductionin pump performance and can be difficult to detect.Manifolds and suction headers are covered in Section9.8.4.3.1.

9.8.4.3 Recommendations

The maximum recommended velocity in the suctionpiping is 2.4 m/s (8.0 ft/s). Velocities may be increasedat the pump suction flange by the use of a gradualreducer. Higher velocities are acceptable providing thepiping design delivers a smooth inlet flow to the pumpsuction as required in Section 9.8.5.6. The velocity inthe suction piping should be constant or increasing asthe flow approaches the pump.

For many common solids-bearing liquids, a velocity ofabout 1.0 m/s (3.0 ft/s) is required to prevent sedimen-tation in horizontal piping. A velocity as low as 0.6 m/s(2.0 ft/s) is generally sufficient for organic solids.

There shall be no flow disturbing fittings (such as par-tially open valves, tees, short radius elbows, etc.)closer than five suction pipe diameters from the pump.Fully open, non-flow disturbing valves, vaned elbows,long radius elbows and reducers are not consideredflow disturbing fittings (refer to Figures 9.8.19 and9.8.20).

Figure 9.8.18 — Common intakes for suction piping showing submergence datum references

Table 9.8.3 — Acceptable velocity ranges for inlet bell diameter “D”

NOTE: See Figure 9.8.25A for corresponding inlet diame-ters (OD), calculated according to D = [Q/(785V)]0.5

NOTE: See Figure 9.8.25B for corresponding inlet diame-ters (OD), calculated according to D = (0.409Q/V)0.5

PumpFlow

Range Q,l/s

RecommendedInlet Bell Design

Velocity,m/s

AcceptableVelocity Range,

m/s

< 315 V = 1.7 0.6 ≤ V ≤ 2.7

≥ 315< 1260

V = 1.7 0.9 ≤ V ≤ 2.4

≥ 1260 V = 1.7 1.2 ≤ V ≤ 2.1

PumpFlow

Range Q,gpm

RecommendedInlet Bell Design

Velocity,ft/s

AcceptableVelocity Range,

ft/s

< 5,000 V = 5.5 2 ≤ V ≤ 9

≥ 5,000< 20,000

V = 5.5 3 ≤ V ≤ 8

≥ 20,000 V = 5.5 4 ≤ V ≤ 7



22

The suction pipe size is usually a larger diameter thanthe suction fitting on the pump. In such cases, a con-centric or eccentric reducer is fitted to accommodatethe difference in pipe size. For horizontal suction pip-ing, the flat side of an eccentric reducer shall belocated on the top. For vertical piping without bendsnear the pump, a concentric reducer isrecommended.

9.8.4.3.1 Suction headers

A suction header, also called a suction manifold, isrequired when two or more pumps are fed from onecommon suction intake. Take-offs directly oppositeeach other are not allowed. The maximum velocityallowed in the suction header is 2.4 m/s (8.0 ft/s). If theratio of the take-off diameter to the header diameter isequal to or greater than 0.3, then the minimum spac-ing between take-offs is 2 header diameters. If thatsame ratio is less than 0.3, the minimum spacingbetween take-offs is 3 take-off diameters. See Figure9.8.22.

9.8.4.3.2 Submergence

For submergence of the suction header intake bell,see Section 9.8.7 and Figure 9.8.18 for calculationmethods and datum references for S and D.

9.8.5 Model tests of intake structures

9.8.5.1 Need for model study

A properly conducted physical model study is a reli-able method to identify unacceptable flow patterns atthe pump suction for given sump or piping designs andto derive acceptable intake sump or piping designs.Considering the cost for a model study, an evaluation

Figure 9.8.19 — Recommended suction piping near pump, all pump types (D = pipe diameter)

FlowDisturbingFitting

Short RadiusElbow

5D Min 5D Min

5DMin

5DMin

Long RadiusElbow

Long RadiusElbow

Figure 9.8.20 — Examples of suction pipe fittings near pump that require approval of the pump manufacturer

Figure 9.8.21 — Recommended suction piping for double suction pumps with the elbow in the same plane as the impeller shaft



23

is needed to determine if a model study is required. Aphysical hydraulic model study shall be conducted forpump intakes with one or more of the following features:

• Sump or piping geometry (bay width, bell clear-ances, side wall angles, bottom slopes, distancefrom obstructions, the bell diameter or pipingchanges, etc.) that deviates from this designstandard.

• Non-uniform or non-symmetric approach flow tothe pump sump exists (e.g., intake from a signifi-cant cross-flow, use of dual flow or drum screens,or a short radius pipe bend near the pump suction,etc.).

• The pumps have flows greater than 2520 l/s(40,000 gpm) per pump or the total station flowwith all pumps running would be greater than6310 l/s (100,000 gpm).

• The pumps of an open bottom barrel or riserarrangement have flows greater than 315 l/s (5000gpm) per pump (see Section 9.8.2.6).

• Proper pump operation is critical and pump repair,remediation of a poor design, and the impacts ofinadequate performance or pump failure alltogether would cost more than ten times the costof a model study.

When evaluating the indirect impacts of inadequateperformance or pump failures, the probability of failure

may be considered, such as by comparing the pro-posed intake design to other intakes of essentiallyidentical design and approach flow which operate suc-cessfully. The model study shall be conducted by ahydraulic laboratory using personnel that have experi-ence in modeling pump intakes.

9.8.5.2 Model objectives

Adverse hydraulic conditions that can affect pump per-formance include: free and sub-surface vortices, swirlapproaching the pump impeller, flow separation at thepump bell, and a non-uniform axial velocity distributionat the suction.

Free-surface vortices are detrimental when their coreis strong enough to cause a (localized) low pressure atthe impeller and because a vortex core implies a rotat-ing rather than a radial flow pattern. Sub-surface vorti-ces also have low core pressures and are closer to theimpeller. Strong vortex cores may induce fluctuatingforces on the impeller and cavitation. Sub-surface vor-tices with a dry-pit suction inlet are not of concern ifthe vortex core and the associated swirling flow dissi-pate well before reaching the pump suction flange.

Pre-swirl in the flow entering the pump exists if a tan-gential component of velocity is present in addition tothe axial component. Swirl alters the inlet velocity vec-tor at the impeller vanes, resulting in undesiredchanges in pump performance characteristics, includ-ing potential vibration.

D1

D2

L1 1L L1

FLOW DISTURBINGFITTING(IF USED)

L 2

2D

D2

2D

PUMP FLANGE

PUMP FLANGE

2L

Figure 9.8.22 — Suction header design options

D2/D1 L1 L2

> 0.3 > 2D1 > 5D2

< 0.3 > 3D2 > 5D2



24

A reasonably uniform axial velocity distribution in thesuction flow (approaching the impeller) is assumed inthe pump design, and non-uniformity of the axialvelocity may cause uneven loading of the impeller andbearings.

A properly conducted physical model study can beused to derive remedial measures, if necessary, toalleviate these undesirable flow conditions due to theapproach upstream from the pump impeller. The typi-cal hydraulic model study is not intended to investigateflow patterns induced by the pump itself or the flowpatterns within the pump. The objective of a modelstudy is to ensure that the final sump or piping designgenerates favorable flow conditions at the inlet to thepump.

9.8.5.3 Model similitude and scale selection

Models involving a free surface are operated usingFroude similarity since the flow process is controlledby gravity and inertial forces. The Froude number, rep-resenting the ratio of inertial to gravitational forces, canbe defined for pump intakes as:

F = u/(gL)0.5 (9.8.5-1)

Where:

u = average axial velocity (such as in the suctionbell)

g = gravitational acceleration

L = a characteristic length (usually bell diame-ter or submergence)

The choice of parameter used for velocity and length isnot critical, but the same parameter must be used inthe model and prototype when determining the Froudenumber.

For similarity of flow patterns, the Froude number shallbe equal in model and prototype:

Fr = Fm/Fp = 1 (9.8.5-2)

where m, p, and r denote model, prototype, and theratio between model and prototype parameters,respectively.

In modeling a pump intake to study the potential for-mation of vortices, it is important to select a reason-ably large geometric scale to minimize viscous andsurface tension scale effects, and to reproduce the

flow pattern in the vicinity of the intake. Also, the modelshall be large enough to allow visual observations offlow patterns, accurate measurements of swirl andvelocity distribution, and sufficient dimensional control.Realizing that larger models, though more accurateand reliable, are more expensive, a balancing of thesefactors is used in selecting a model scale. However,the scale selection based on vortex similitude consid-erations, discussed below, is a requirement to avoidscale effects and unreliable test results.

Fluid motions involving vortex formation have beenstudied by several investigators (Anwar, H.O. et al.,1978; Hecker, G.E., 1981; Padmanabhan, M. andHecker, G.E., 1984; Knauss, J., 1987). It can be shownby the principles of dimensional analysis that such flowconditions at an intake are governed by the followingdimensionless parameters:

uD/Γ, u/(gD)0.5, D/S, uD/ν, and u2D/(σ/ρ)

Where:

u = average axial velocity (e.g., at the bellentrance)

Γ = circulation of the flow

D = diameter (of the bell entrance)

S = submergence (at the bell entrance)

ν = kinematic viscosity of the liquid

g = acceleration due to gravity

σ = surface tension of liquid/air interface

ρ = liquid density

The influence of viscous effects is defined by theparameter uD/ν = R, the Reynolds number, and sur-face tension effects are indicated by u2D/(σ/ρ) = We,the Weber number. Based on the available literature,the influence of viscous forces and surface tension onvortexing may be negligible if the values of R and Wein the model fall above 3 × 104 and 120, respectively,(Daggett, L., and Keulegan, G.H., 1974; Jain, A.K. etal., 1978).

With negligible viscous and surface tension effects,dynamic similarity is obtained by equating the parame-ters uD/Γ, u/(gD)0.5, and D/S in the model and proto-type. An undistorted geometrically scaled Froudemodel satisfies this condition, provided the approach



25

flow pattern in the vicinity of the sump, which governsthe circulation, Γ, is properly simulated.

Based on the above similitude considerations andincluding a safety factor of 2 to ensure minimum scaleeffects, the model geometric scale shall be chosen sothat the model bell entrance Reynolds number andWeber number are above 6 × 104 and 240, respec-tively, for the test conditions based on Froude simili-tude. No specific geometric scale ratio isrecommended, but the resulting dimensionless num-bers must meet these minimum values. For practicalityin observing flow patterns and obtaining accuratemeasurements, the model scale shall yield a bay widthof at least 300 mm (12 inches), a minimum liquid depthof at least 150 mm (6 inches), and a pump throat orsuction diameter of at least 80 mm (3 inches) in themodel.

In a model of geometric scale Lr, with the model oper-ated based on Froude scaling, the velocity, flow, andtime scales are, respectively:

Vr = Vm /Vp = Lr0.5 (9.8.5-3)

Qr = Qm /Qp = Lr2Vr = Lr

2.5 (9.8.5-4)

Tr = Tm /Tp = Lr /Vr = Lr0.5 (9.8.5-5)

Even though no scale effect of any significance isprobable in models with geometric scales selected asdescribed above, as a conservative procedure con-forming to common practice, a few tests for the finaldesign of a free surface intake shall be conducted at1.5 times the Froude scaled flows, keeping the sub-mergence at the geometrically scaled values. By thisprocedure, the circulation contributing to vorticeswould presumably be increased, resulting in a conser-vative prediction of (stronger) vortices. Tests at proto-type velocities are not recommended, as this willdistort approach flow patterns and unduly exaggerateflow disturbances (e.g., vortices) in the model.

Models of closed conduit piping systems leading to apump suction are not operated based on Froude simil-itude, but need to have a sufficiently high pipe Rey-nolds number, R = uDP/ν, such that flow patterns arecorrectly scaled. Based on available data on the varia-tion of loss coefficients and swirl with Reynolds num-ber, a minimum value of 1 × 105 is recommended forthe Reynolds number at the pump suction.

9.8.5.4 Model scope

Selection of the model boundary is extremely impor-tant for proper simulation of flow patterns at the pump.As the approach flow non-uniformities contribute sig-nificantly to the circulation causing pre-swirl and vorti-ces, a sufficient area of the approach geometry orlength of piping has to be modeled, including anychannel or piping transitions, bends, bottom slopechanges, control gates, expansions and any significantcross-flow past the intake.

All pertinent sump structures or piping features affect-ing the flow, such as screens and blockage due to theirstructural features, trash racks, dividing walls, col-umns, curtain walls, flow distributors, and piping transi-tions must be modeled. Special care should be takenin modeling screens; the screen head loss coefficientin the model shall be the same as in the prototype.The head loss coefficient is a function of the screenReynolds number, the percent open area, and thescreen (wire) geometry. Scaling of the prototypescreen wire diameter and mesh size to the selectedmodel geometric scale may be impractical andimproper due to the resulting low model Reynoldsnumber. In some cases, a model could use the samescreen as the prototype to allow equal loss coeffi-cients. Scaling of trash racks bars may also be imprac-tical and lead to insufficient model bar Reynoldsnumber. Fewer bars producing the same total block-age and the same flow guidance effect (bar to spaceaspect ratio) may be more appropriate.

The inside geometry of the bell up to the bell throat(section of maximum velocity) shall be scaled, includ-ing any hub located between the bell entrance and thethroat. The bell should be modeled of clear plastic orsmooth fiberglass, the former being preferred for flowvisualization. The outside shape of the bell may beapproximated except in the case of multi-stage pumps,in which case the external shape may affect flow pat-terns approaching the inlet bell. The impeller is notincluded in hydraulic models, as the objective is toevaluate the effect of the intake design on flow pat-terns approaching the impeller. A straight pipe equal tothe throat diameter or pump suction diameter shallextend at least five diameters downstream from thethroat or pump suction.

For free surface intakes, the model shall provide up to1.5 times the Froude scaled maximum flow per pumpto evaluate potential scale effects on free surface vorti-ces, as discussed above, and be deep enough tocover the range of scaled submergence.



26

9.8.5.5 Instrumentation and measuring techniques

Unless agreed upon circumstances indicate otherwise,the following measurements shall be made. The extentof the measurements is summarized in Section9.8.5.7, Test Plan, below.

Flow: The outflow from each simulated pump shall bemeasured with flow meters. If an orifice or venturimeter conforming to ASME standards is used, themeter need not be calibrated. The accuracy of the flowmeasurement shall be within ±2% of the actual flowrate.

Liquid Level: Liquid surface elevations shall be mea-sured using any type of liquid level indicator accurateto at least 3 mm (0.01 ft) in the model.

Free Surface Vortices: To evaluate the strength of vor-tices at pump intakes systematically, the vortexstrength scale varying from a surface swirl or dimple toan air core vortex, shown in Figure 9.8.23A, shall beused. Vortex types are identified in the model by visualobservations with the help of dye and artificial debris,and identification of a coherent dye core to the pumpbell or pump suction flange is important. Vortices areusually unsteady in strength and intermittent in occur-rence. Hence, an indication of the persistence of vary-ing vortex strengths (types) shall be obtained throughobservations made at short intervals in the model(e.g., every 15 seconds) for at least 10 minutes, so thata vortex type versus frequency evaluation can bemade and accurate average and maximum vortextypes may be determined. Such detailed vortex obser-vations are needed only if coherent dye core (or stron-ger) vortices exist for any test. Photographic or videodocumentation of vortices is recommended.

VortexType

VortexType

1

3

5

2

4

6

Trash

Surface swirl

Dye core to intake:coherent swirlthroughoutwater column

Vortex pulling airbubbles to intake

Full air coreto intake

Vortex pullingfloating trashbut not air

Surface dimplecoherent swirl

A. FREE SURFACE VORTICES

B. SUB-SURFACE VORTICES

1 Swirl 2 Dye core 3 Air core or bubbles

Figure 9.8.23 — Classification of free surface and sub-surface vortices



27

Sub-surface Vortices: Sub-surface vortices usually ter-minate at the sump floor and walls, and may be visibleonly when dye is injected near the vortex core. Theclassification of sub-surface vortices, given in Figure9.8.23B shall be used. The possible existence of sub-surface vortices must be explored by dye injection atall locations on the wall and floor around the suctionbell where a vortex may form, and documentation ofpersistence shall be made, as for free surface vortices.

Pre-Swirl: Visual observations of the orientation ofeight or more equally spaced yarns mounted to form acircle equal to the (outer) bell diameter and originatingabout one half the bell floor clearance are useful (butnot required) to evaluate qualitatively any pre-swirl atthe bell entrance. The yarns shall be one half the bell-to-floor clearance in length.

Swirl in the Suction Pipe: The intensity of flow rotationshall be measured using a swirl meter, see Figure9.8.24, located about four suction pipe diametersdownstream from the bell or pump suction. The swirlmeter shall consist of a straight vaned propeller withfour vanes mounted on a shaft with low friction bear-ings. The tip to tip vane diameter is 75% of the pipediameter and the vane length (in the flow direction) isequal to 0.6 pipe diameters. The revolutions per unittime of the swirl meter are used to calculate a swirlangle, θ, which is indicative of the intensity of flowrotation.

θ = tan-1(πdn/u) (9.8.5-6)

Where:

u = average axial velocity at the swirl meter

d = diameter of the pipe at the swirl meter

n = revolutions/second of the swirl meter

Flow swirl is generally unsteady, both in direction ofrotation and speed of rotation. Therefore, swirl meterreadings shall be obtained continuously; for example,readings during consecutive intervals of 10 to 30 sec-onds, covering a period of at least 10 minutes in themodel. Swirl meter rotation direction shall also benoted for each short duration. The maximum shortduration swirl angle and an average swirl angle shallbe calculated from the swirl meter rotations (seeAcceptance Criteria below). Swirl at a dry-pit suctioninlet is not of concern if the swirl dissipates beforereaching the pump suction flange.

Velocity Profiles: Cross-sectional velocity profiles ofthe approach flow may be obtained using a propellermeter or other suitable device at a sufficient number ofmeasuring points to define any practical skewness inthe approach flow. The cross section location shall beselected to be representative of the approaching flowprior to being influenced by the pump, such as at a dis-tance of two intake widths upstream from the pumpcenterline. Such measurements are in themselves notcritical or required, but allow a better understanding ofhow the approach flow may be contributing to otherflow irregularities and what type of remedial devicesmay be effective.

Velocity traverses along at least two perpendicularaxes at the throat of the model suction bell or at theplane of the pump suction in a piping system shall beobtained for the final design using a pitot-static tube orother suitable instrument capable of determining theaxial velocity component with a repeatability of ±2% orbetter. To allow velocity fluctuations to be properlymeasured and recorded versus time, care should betaken that no unnecessary physical or electronicdamping is introduced. The angularity of the actualvelocity vector relative to the axis of the pump or suc-tion piping shall be observed at three or more loca-tions with dye or strings to ensure that there are nolarge deviations from axial flow.

Figure 9.8.24 — Typical swirl meter

SWIRL METER(with low- friction bearings)

FLOW

VELOCITYTRAVERSE

0.75d

4d(approx)

0.6d

D

d



28

9.8.5.6 Acceptance criteria

The acceptance criteria for the model test of the finaldesign shall be the following:

• Free surface and sub-surface vortices entering thepump must be less severe than vortices withcoherent (dye) cores (free surface vortices of Type3 and sub-surface vortices of Type 2 in Figure9.8.23). Dye core vortices may be acceptable onlyif they occur for less than 10% of the time or onlyfor infrequent pump operating conditions.

• Swirl angles, both the short-term (10 to 30 secondmodel) maximum and the long-term (10 minutemodel) average indicated by the swirl meter rota-tion, must be less than 5 degrees. Maximumshort-term (10 to 30 second model) swirl anglesup to 7 degrees may be acceptable, only if theyoccur less than 10% of the time or for infrequentpump operating conditions. The swirl meter rota-tion should be reasonably steady, with no abruptchanges in direction when rotating near the maxi-mum allowable rate (angle).

• Time-averaged velocities at points in the throat ofthe bell or at the pump suction in a piping systemshall be within 10% of the cross-sectional areaaverage velocity. Time-varying fluctuations at apoint shall produce a standard deviation from thetime-averaged signal of less than 10%.

• For the special case of pumps with double suctionimpellers, the distribution of flow at the pump suc-tion flange shall provide equal flows to each sideof the pump within 3% of the total pump flow.

9.8.5.7 Test plan

Operating conditions to be tested shall include theminimum, intermediate and maximum liquid levels andflows. If there are multiple pumps, all possible combi-nations of operating conditions should be included.Even though vortices are probably most severe atmaximum flows and minimum submergence, there areinstances where stronger vortices may occur at higherliquid levels and lower flows, perhaps due to lessturbulence.

Vortex observations and swirl measurements shall bemade for all tests. Axial velocity measurements at thebell throat or suction inlet for each pump in the modelare recommended at least for the one test indicatingthe maximum swirl angle for the final design. Still-

photographic documentation of typical tests showingvortexing or other flow problems shall be made.

The initial design shall be tested first to identify anyhydraulic problems. If any objectionable flow problemsare indicated, modifications to the intake or pipingshall be made to obtain satisfactory hydraulic perfor-mance. Modifications may be derived using one or twoselected test conditions indicating the most objection-able performance.

Practical aspects of installing the modifications shouldbe considered. The performance of the final modifieddesign shall be documented for all operating conditions.If any of the tests show unfavorable flow conditions,further revisions to the remedial devices shall bemade. For intakes with a free surface, most tests shallbe at Froude scaled flows; however, a few selectedtests for the final design shall be repeated at 1.5 timesthe Froude scaled flows to compensate for any possi-ble scale effects on free-surface vortices. No velocitymeasurements shall be conducted at higher thanFroude-scaled flows. It is recommended that represen-tative tests of the final design be witnessed by theuser, the pump manufacturer, and the station designer.

9.8.5.8 Report preparation

The final report of the model study shall include: intakeor piping design, model description, scaling and simili-tude criteria, instrumentation, test procedure, results(data tabulated and plotted), recommended modifica-tions and conclusions. The report shall contain photo-graphs of the model showing the initial and finaldesigns, drawings of any recommended modifications,and photographs of relevant flow conditions identifiedwith dye or other tracers. A brief video tape of typical flowproblems observed during the tests is recommended.

9.8.6 Inlet bell design diameter (D)

Designing a sump to achieve favorable inflow to thepump or suction pipe bell requires control of varioussump dimensions relative to the size of the bell. Forexample, the clearance from the bell to the sump floorand side walls and the distance to various upstreamintake features is controlled in these standards byexpressing such distances in multiples of the pump orinlet bell diameter. Such standardization of conditionsleading to, and around, the inlet bell reduces the prob-ability that strong submerged vortices or excessivepre-swirl will occur. Also, the required minimum sub-mergence to prevent strong free-surface vortices isrelated to the inlet bell (or pipe) diameter (see Section9.8.7).



29

If the pump or pipe suction inlet diameter D has beenselected prior to designing the sump, then the sumpdesign process (see Table 9.8.2) can proceed withoutusing the information provided in this section. How-ever, only the use of inlet sizes within the guidelinesprovided in this section will produce sump dimensionsthat comply with these standards. Use of bell or inletdiameters outside the range recommended herein willalso comply with these standards if a hydraulic study isconducted in accordance with Section 9.8.5 to confirmacceptable inflow conditions as required by Section9.8.5.6.

If the pump (or pipe suction inlet) has not beenselected, it is recommended that the inlet bell diameterbe chosen based on achieving the bell inlet velocitythat experience indicates provides acceptable inflowconditions to the pump. The bell inlet velocity isdefined as the flow through the bell (i.e., the pumpflow) divided by the area of the bell, using the outsidediameter of the bell. Information on acceptable aver-age bell inlet diameter velocities is provided in Figure9.8.25, based on a survey of inlet bell diameters usedby pump vendors and industry experience. The solidline represents the average pump bell diameter fromthe survey, corresponding to a bell inlet velocity of1.7 m/s (5.5 ft/s). Using industry experience and aboutone standard deviation of the range of inlet bell sizeswhich may be provided by pump vendors for a givenflow indicates that the recommended inlet bell velocity,V, may vary as follows:

a) for flows less than 315 l/s (5000 gpm), the inlet bell(or inlet pipe) velocity shall be 0.6 to 2.7 m/s (2.0to 9.0 ft/s)

b) for flows equal to or greater than 315 l/s (5000gpm), but less than 1260 l/s (20,000 gpm), thevelocity shall be 0.9 to 2.4 m/s (3.0 to 8.0 ft/s)

c) for flows equal to or greater than 1260 l/s (20,000gpm), the velocity shall be 1.2 to 2.1 m/s (4.0 to7.0 ft/s).

These permissible ranges in inlet bell velocity are givenin Table 9.8.3 and are also shown on Figure 9.8.25 interms of the recommended bell diameter range for agiven flow per pump or inlet. Although the survey indi-cated that pumps with bells outside this range may beproposed, experience indicates that inlet bell (or inletpipe) velocities higher than the recommended rangeare likely to cause hydraulic problems. Use of lowervelocities would produce unnecessarily large pumpbells (or inlet pipes) and, therefore, sumps.

For sump design prior to pump selection, the recom-mended inlet bell diameter shown on Figure 9.8.25shall be used. This recommended bell diameter isbased on an inlet velocity of 1.7 m/s (5.5 ft/s). This pro-cess will allow the sump design to proceed. When thepump is specified and selected, the outside diameterof its bell (without added horizontal rings or “umbrel-las,” sometimes used as vortex suppressor) shall fallwithin the acceptable range to produce an inlet velocitywithin the limits indicated in Table 9.8.3. An inlet belldiameter within this range will produce a sump geome-try that complies with these standards on minimumsubmergence and sump dimensions, without changingthe sump design based on the recommended inlet belldiameter.

9.8.7 Required submergence for minimizing surface vortices

9.8.7.1 Introduction

This section concerns the recommended minimumsubmergence of a pump bell or pipe intake to reducethe probability that strong free-surface air core vorticeswill occur. Submerged vortices are not believed to berelated to submergence and are not considered in thissection. If a submergence greater than recommendedherein is needed to provide the required NPSH for thepump, that greater submergence would govern andmust be used.

Approach-flow skewness and the resulting circulationhave a controlling influence on free-surface vortices inspite of adequate submergence. Due to the inability topredict and quantify approach flow characteristics foreach particular case without resorting to hydraulicmodel studies, and the lack of available correlationbetween such characteristics and vortex strength, therecommended minimum submergence given herein isfor a reasonably uniform approach flow to the pumpsuction bell or pipe inlet. Highly non-uniform (skewed)approach flows will require the application of vortexsuppression devices (not part of this standard) suchas those offered for information in Appendix A. Suchdevices can be more practical in suppressing vorticesthan increased submergence.

Even for constant flows, vortices are not steady inposition or strength, usually forming and dissipatingsporadically. This is due to the random nature by whicheddies merge to form coherent circulation around a fil-ament and by which turbulence becomes sufficient inintensity to disrupt the flow pattern. For these reasons,the strength of vortices versus time shall be observedto obtain an average and a maximum vortex type for



30

given conditions, and this process is enhanced bydefining a measure of vortex strength, as illustrated inFigure 9.8.23.

9.8.7.2 Controlling parameters

By use of dimensional analysis, it may be shown that agiven vortex type, VT, is a function of various dimen-sionless parameters.

VT = ƒ(FD, NΓ, S/D, G)

Where:

VT = vortex type (strength and persistence)

ƒ = a function

FD = Froude No. = V/(gD)0.5

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000

Q = Flow, liters/sec

V = 1.2 m/s

V = 2.1 m/s

V = 1.7 m/sRecommended

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

0 200 400 600 800 1,000 1,200 1,400

V = 0.6 m/s

V = 0.9 m/s

V = 2.4 m/s

V = 2.7 m/s

V = 1.7 m/sRecommended

D =

Bel

l Des

ign

Dia

., m

eter

sD

= B

ell D

esig

n D

ia.,

met

ers


V = Average bell velocity, m/s Q = flow, l/s D = Outside Bell Diameter, m = [Q/(785V)]0.5

Figure 9.8.25A — Recommended inlet bell design diameter (OD)



31

NΓ = Circulation No., ΓD/Q, of approach flow

S = Submergence

D = Diameter of inlet or bell

G = Geometry

Γ = Circulation (2πrVt for concentric flow abouta point with a tangential velocity Vt atradius r)

V = Velocity at inlet (= 4Q/πD2)

g = Gravitation acceleration

Q = Flow

20

40

60

80

100

120

140

160

180

0 50,000 100,000 150,000 200,000 250,000 300,000

Q = Flow, gpm

V = 4.0 ft/s

V = 7.0 ft/s

V = 5.5 ft/sRecommended

D =

Bel

l Des

ign

Dia

., in

ches

0

10

20

30

40

50

60

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000Q = Flow, gpm

V = 2.0 ft/s

V = 3.0 ft/s

V = 8.0 ft/s

V = 9.0 ft/s

V = 5.5 ft/sRecommended

D =

Bel

l Des

ign

Dia

., in

ches

V = Average bell velocity, ft/s Q = flow, gpm D = Outside Bell Diameter, inches = (0.409Q/V)0.5

Figure 9.8.25B — Recommended inlet bell design diameter (OD) (US units)



32

For a given geometry and approach flow pattern, thevortex strength would only vary with the remainingparameters, that is

VT = ƒ(FD, S/D)

This formula indicates that a plot of S/D vs. FD wouldcontain a family of curves, each representing differentvalues of vortex strength, VT (refer to Figure 9.8.23A).Selection of one vortex strength of concern, such as avortex without air entrainment, would yield a uniquerelationship between S/D and FD which correspondsto that vortex, all for a given geometry and approachflow pattern (circulation).

For typical intake geometry and relatively uniformapproach flow (i.e., low values of the circulationparameter), data and experience suggests that the fol-lowing recommended relationship between submer-gence and the Froude number corresponds to anacceptable vortex strength (Hecker, G.E.,1987).

S/D = 1.0 + 2.3FD (9.8.7-1)

Where:

S = Submergence above a horizontally ori-ented inlet plane (vertical inlet pipe) orabove the centerline of a vertically orientedinlet plane (horizontal inlet pipe)

D = Diameter of inlet opening (equivalent diam-eter for non-circular openings, giving thesame area as a circular opening)

FD = Froude No. = V/(gD)0.5

V = Velocity at inlet face = Flow/Area

This equation indicates that one diameter of submer-gence must be provided, even at negligible inlet flowsor velocities, and that the relative submergence, S/D,increases from that value as the inlet velocityincreases. This is reasonable, since the inlet velocity(flow) provides the energy to cause a potentiallygreater vortex strength if the relative submergencewere not increased.

The relative submergence would only be constant ifthe Froude number for various inlets were constant.Information collected by the Hydraulic Institute (notincluded herein) shows that the average inlet Froudenumber for bells of typical pump applications is notconstant, and that a range of Froude numbers wouldbe possible at a given design flow. Even the restricted

range of inlet bell diameters (and velocities) at a givenflow recommended in Section 9.8.6 allows some varia-tion in the Froude number. Thus, Equation 9.8.7-1 is rec-ommended, rather than a fixed relative submergence.

9.8.7.3 Application considerations

For a given flow, Q, an inlet diameter may be selectedin accordance with Section 9.8.6. The recommendedminimum submergence for that diameter D would begiven by

Metric:

S = 1.0D + 2.3[Q/(0.785D2)/(gD)0.5]D

or

S = D + Q/D1.5/1069

NOTE: S is in meters for g = 9.8 m/sec2, Q in l/s,and D in meters.

US units:

S = 1.0D + 2.3[(12 × 0.409Q/D2)/(12gD)0.5]D

or

S = D + 0.574Q/D1.5

NOTE: S is in inches for g = 32.2 ft/sec2, Q in gpm,and D in inches.

The above illustrates that the actual submergencedepends on the selection of D for a given flow. As Dincreases, the first term causes an increase in sub-mergence, whereas the second term causes adecrease. These opposing trends imply a minimumvalue of S at some D for a given flow, and differentiat-ing S with respect to D, allows determining that value.However, for the range of recommended bell diame-ters in Section 9.8.6, the change of S with D for a givenflow is minimal, and D for pump bells should beselected based on other considerations.

For the inlet bell design diameter recommended inSection 9.8.6, the required minimum submergence forreducing the severity of free-surface vortices is shownon Figure 9.8.26. This figure also shows the recom-mended minimum submergence for the limits of thebell diameter that comply with these standards, seeFigure 9.8.25 and Table 9.8.3. Due to the smallchange in submergence, no change in submergencefrom that calculated with the recommended bell



33

1.5

2.5

3.5

4.5

5.5

6.5

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000


Bell D for 1.2 m/s

Bell D for 2.1 m/s

Bell D for 1.7 m/sRecommended

S =

Bel

l Sub

mer

genc

e, m

eter

s

0.0

0.5

1.0

1.5

2.0

2.5

0 200 400 600 800 1,000 1,200 1,400


Bell D for 0.6 m/s

Bell D for 0.9 m/s

Bell D for 2.4 m/s

Bell D for 2.7 m/s

Bell D for 1.7 m/sRecommended

S =

Bel

l Sub

mer

genc

e, m

eter

s

Figure 9.8.26A — Recommended minimum submergence to minimize free surface vortices



34

50

100

150

200

250

0 50,000 100,000 150,000 200,000 250,000 300,000

Q = Flow, gpm

Bell D for 7.0 ft/sBell D for 5.5 ft/sRecommended

S =

Bel

l Sub

mer

genc

e, in

ches

Bell D for 4.0 ft/s

0

20

40

60

80

100

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000Q = Flow, gpm

Bell D for 2.0 ft/s

Bell D for 3.0 ft/s

Bell D for 8.0 ft/s

Bell D for 9.0 ft/s

S =

Bel

l Sub

mer

genc

e, in

ches

Bell D for 5.5 ft/sRecommended

Figure 9.8.26B — Recommended minimum submergence to minimize free surface vortices (US units)



35

diameter is needed, as long as the final selected belldiameter is within the limits that comply with thesestandards.

9.8.8 Glossary and nomenclature

9.8.8.1 Glossary

Terms Definition

Active storage Liquid stored between low and high liquid levels in the wet well and in upstream piping.

Air Core Vortex A vortex strong enough to form an elongated core of air (see type 6, Figure 9.8.23.

Anti-Rotation Baffle Device used to inhibit the rotation of fluid at or near the suction.

Approach Channel A structure that directs the flow to the pump.

Approach pipe A pipe laid at a gradient sufficient to cause super-critical flow and used to contain a por-tion of the active storage requirement for a constant speed pump.

Axial Flow (propeller)Pump

High flow rate/low head, high specific speed pump.

Backwall A vertical surface behind the inlet to a suction fitting.

Backwall Clearance The distance between the backwall and the point of closest approach of the suction fitting.

Backwall Splitter A device formed or fabricated and attached to the backwall that guides the movement offlow at or near a suction.

Baffles Obstructions that are arranged to provide a more uniform flow at the approach to apump or suction inlet.

Barrel Suction Inlet formed by a “can” encompassing and providing for the suction of a pump.

Bay A portion of an intake structure configured for the installation of one pump.

Bell The entrance to an axial flow pump or the flared opening leading to pump inlet piping.

Benching A type of fillet used to minimize stagnant zones by creating a sloping transition betweenvertical and horizontal surfaces. Benching is applied between sump walls and thesump bottom, or between the back wall and the sump bottom. It is also referred to asfillets, such as “side wall fillets” and “back wall fillets.”

Cavitation Formation and implosion of liquid vapor bubbles caused by low local pressures.

Cell A structure intended to confine the liquid approaching the intake to a pump (see Bay).

Check Valve Piping component used to prevent reverse flow.

Circular Well A suction chamber circular in shape in plan.

Cone See “Floor Cone.”

Critical Depth The liquid depth which has the minimum specific energy for a given flow, correspondingto a Froude Number equal to one (1) .

Curtain Wall A near vertical plate or wall located in an intake that extends below the normal low liquidlevel to suppress vortices.

Double Suction Impel-ler

An impeller provided with a single suction connection that separates and conveys thefluid to two suction areas.

Dry-Pit Suction Suction from a well that conveys fluid to a pump located in a non-wetted environment.

Dual Flow Screens Screening that provides two flow paths for liquid, not in-line with the main flow.

Eddy A local rotational flow pattern disturbing regular streamlines (a vortex).

End Suction Pump A pump that has a suction flange coaxial to the impeller shaft and the pump volute isusually not submerged in the sump.

Fillet A triangular element at the vertex of two surfaces to guide the flow.

Floor Clearance The distance between the floor and the suction bell or opening.

Floor Cone A conical fixture placed below the suction between the floor and the suction bell.



36

Floor Vane A vertical plate aligned with the approach flow and centered under the suction bell.

Flow Straighter Any device installed to provide more uniform flow.

Foot Valve Any device located in the suction of a pump that is designed to keep the line flooded/primed.

Forebay The region of an intake before individual partitioning of flow into individual suctions orintake bays.

Formed SuctionIntake

A shaped suction inlet that directs the flow in a particular pattern into the pump suction.

Free Surface Flow Open channel or unconfined flow.

Froude Number A dimensionless grouping of parameters used in flow analysis and modeling that indi-cates the relative influence of inertial compared to gravitational forces (see Equation9.8.5-1).

Guide Vanes Devices used in the suction approach that directs the flow in an optimal manner.

Hydraulic Jump A turbulent sudden increase in liquid depth as the flow decelerates from super-critical tosub-critical flow.

Hydrocone See “Floor Cone.”

Intake The structure or piping system used to conduct fluid to the pump suction.

Intake Velocity The average or bulk velocity of the flow in an intake.

Mixer A mechanical device that produces an axial propeller jet, often used for maintaining sus-pension of solids-bearing liquids in wet wells and tanks.

Mixing Nozzles Nozzles attached to the pump volute or the discharge pipe designed to mix solids in awet well.

Multiplex Pumping Pump installations where sets of pumps are used, such as duplex (two) or triplex(three).

NPSHR The amount of suction head, over vapor pressure, required to prevent more than a 3%loss in total head from the first stage impeller at a specific flow rate.

Ogee Rampor Spillway

The gradual change in shape/slope in the floor of an intake, shaped like an elongatedletter “S.”

Perforated Baffles Plate device with specifically sized openings, either vertical or horizontal, applied to pro-duce uniform approach velocity.

Physical HydraulicModel

A reduced-scale replicate of the geometry that controls approach flow patterns operatedaccording to certain similitude laws for flow, velocity and time.

Piping Reducer Any change in pipe size, or line area, that results in either an increase or decrease invelocity.

Pre-swirl Rotation of the flow at the pump suction due to the approach flow patterns.

Pump A device used to convey fluid from a low-energy level to a higher one.

Pump Column Part of the pump assembly that both connects the pump to the discharge head and noz-zle and conveys fluid into the system.

Pump Suction Bell A part of the pump that provides an opening to convey flow into the suction eye of theimpeller.

Rectangular Wet Well Any wet well in which pumps are arranged along a wall opposite the influent conduit.The shape may be square, rectangular or trapezoidal.

Reynolds Number A dimensionless grouping of parameters used in flow analysis and modeling that indi-cates the relative influence of inertial compared to viscous forces (see Section9.8.5.3).

Terms Definition



37

Scale The ratio between geometric characteristics of the model and prototype.

Scale Effect The impact of reduced scale on the applicability of test results to a full-scale prototype.

Sediment Settleable materials suspended in the flow.

Septicity A condition in which stagnant domestic sewage turns septic due to a lack of oxygen.

Snoring The condition that occurs when a pump is allowed to draw down the liquid level veryclose to the pump’s inlet. Snoring refers to the gurgling sound associated with contin-uous air entrainment.

Solids Material suspended in the liquid.

Specific Energy Pressure head plus velocity head referenced to the invert of a conduit.

Specific Speed Equivalent to a dimensionless number, a high value denotes a high-flow – low-headpump while a low value denotes a low-flow – high-head pump.

Soffit Inside top of a pipe.

Sequent Depth The depth of liquid following a hydraulic jump.

Submergence The height of liquid level over the suction bell or pipe inlet.

Submersible Pump A close coupled pump and drive unit designed for operation while immersed in thepumped liquid.

Suction Bell Diameter Overall OD of the suction connection at the entrance to a suction.

Suction Head Pressure available at the pump suction, usually positive if the liquid level is at a higherelevation than the pump suction.

Suction Lift Negative pressure at the pump suction, usually a result of the liquid level being at alower elevation than the pump suction.

Suction Scoop A device added to the suction to change the direction of flow. Refer to Formed SuctionIntake.

Suction Strainer A device located at the inlet to either protect the pump or provide flow stability at thesuction.

Sump A pump intake basin or wet well. See Forebay.

Swirl Rotation of fluid around its mean, axial flow direction.

Swirl Angle The angle formed by the axial and tangential (circumferential) components of a velocityvector (see Equation 9.8.5-7).

Swirl Meter A device with four flat vanes of zero pitch used to determine the extent of rotation in oth-erwise axial flow.

Trench Intake An intake design that aligns the pump suctions in-line with, but below, the inflow. A typeof forebay.

Turning Vanes Devices applied to the suction to alter the direction of flow.

Unconfined Suction/Intake

Suction in a free flow field with no lateral physical boundaries.

Unitized Intake A multiple pump intake with partitioned pump bays.

Vane See Floor Vane.

Volute The pump casing for a centrifugal type of pump, generally spiral or circular in shape.

Vortex A well-defined swirling flow core from either the free surface or from a solid boundary tothe pump inlet (see Figure 9.8.23).

Vortex, Free Surface A vortex that terminates at the free surface of a flow field.

Vortex, Subsurface A vortex that terminates on the floor or side walls of an intake.

Wall Clearance Dimensional distance between the suction and the nearest vertical surface.

Terms Definition



38

9.8.8.2 Nomenclature

Wastewater Description of fluid that typically carries suspended waste material from domestic orindustrial sources.

Weber Number A dimensionless grouping of parameters used in flow analysis and modeling that indi-cates the relative influence of inertial compared to surface tension forces (see Sec-tion 9.8.5.3).

Wet-Pit Suction A suction with the pump fully wetted.

Wet Well A pump intake basin or sump having a confined liquid volume with a free water surfacedesigned to hold liquid in temporary storage to even out variations between inflowand outflow. See Forebay.

Terms Definition

Sym. Definition Reference Location

A Distance from the pump inlet centerline tothe intake structure entrance

Fig. 9.8.1, Table 9.8.1

At Empty area Table C.1, Table C.2

At Total area Table C.1, Table C.2

a Length of constricted bay section near thepump inlet

Fig. 9.8.2, Table 9.8.1

B Distance from the back wall to the pumpinlet bell centerline

Fig. 9.8.1, Table 9.8.1, Fig. 9.8.18

C Distance between the inlet bell and floor Fig. 9.8.1, Table 9.8.1, Fig. 9.8.18

Cb Inlet bell or volute clearance for circularpump stations

9.8.2.3.2.1, 9.8.2.3.2.4, Fig. 9.8.4, Fig. 9.8.5

Cf Floor clearance on circular pump stations 9.8.2.3.2.1, 9.8.2.3.2.2, Fig. 9.8.4, Fig. 9.8.5

Cw Wall clearance on circular pump stations 9.8.2.3.2.1, 9.8.2.3.2.3, Fig. 9.8.4, Fig. 9.8.5

D Inlet bell diameter or inlet bell designdiameter

Foreword, 9.8.2.1.3, 9.8.2.1.4, Eq. 9.8.2.1-1,Eq. 9.8.2.1-2, Fig. 9.8.1, Fig. 9.8.2, Table 9.8.1,Table 9.8.2, 9.8.2.3.2.2, 9.8.2.3.2.3, 9.8.2.4.7,9.8.2.4.8, 9.8.2.4.9, Fig. 9.8.6, Fig. 9.8.11, 9.8.2.7.2,9.8.2.7.4, 9.8.3.2.3.1, 9.8.3.2.3.2, Fig. 9.8.13,Fig. 9.8.14, 9.8.3.3.3, Fig. 9.8.17, 9.8.3.4.4.1,Fig. 9.8.18, 9.8.5.3, 9.8.6, Table 9.8.3, Fig. 9.8.25,9.8.7.2, Eq. 9.8.7-1, Fig. 9.8.26, Fig. A.10, Fig. A.11

D Diameter of circle with area equivalent torectangular area at FSI entrance

9.8.2.2.3

D Tank outlet fitting diameter 9.8.2.5.4, Fig. 9.8.9, 9.8.2.5.5

D Turning vane inlet diameter 9.8.2.6.4, Fig. 9.8.10

D Pipe diameter Fig. 9.8.19

D1 Vertical can riser diameter Fig. 9.8.10

D1 Can inside diameter Fig. 9.8.11, Fig. 9.8.12

D1 Diameter of suction header Fig. 9.8.22

D2 Diameter of suction header take-off pipe Fig. 9.8.22

Db Inlet bell or volute diameter 9.8.2.3.2.1, 9.8.2.3.2.6, Fig. 9.8.4, Fig. 9.8.5

DM Well motor cooling shroud diameter Fig. 9.8.12



39

Dp Inside diameter of approach pipe C-2, C-3, Table C.1, Table C.2

Ds Sump diameter 9.8.2.3.2.1, 9.8.2.3.2.5, Fig. 9.8.4, Fig. 9.8.5

DT Theoretical diameter 9.8.2.6.6

d Diameter at outlet of formed suctionintake

Fig. 9.8.3, Type 10 formed suction intake

d Diameter of the pipe at the swirl meter Eq. 9.8.5-7, Fig. 9.8.24

EGL Energy grade line C-3

F Froude number 9.8.5.3, Eq. 9.8.5-1

FD Froude number Foreword, Fig. 9.8.1, Eq. 9.8.2.1-1, Eq. 9.8.2.1-2,Table 9.8.1, 9.8.2.1.4, 9.8.2.2.3, 9.8.2.5.4, 9.8.2.7.4,Fig. 9.8.13, Eq. 9.8.7-1, 9.8.7.2

Fr Froude number ratio, Fm/Fp 9.8.5.3, Eq. 9.8.5-2

Fm Froude number of model 9.8.5.3, Eq. 9.8.5-2

Fp Froude number of prototype 9.8.5.3, Eq. 9.8.5-2

G Geometry 9.8.7.2

g Acceleration of gravity 9.8.2.1.4, Eq. 9.8.2.1-1, 9.8.2.5.4, 9.8.5.3, Eq. 9.8.5-1,9.8.7.2, 9.8.7.3

H Minimum liquid depth Fig. 9.8.1, Fig. 9.8.2, Table 9.8.1, Fig. 9.8.18

Hf Height of FSI Fig. 9.8.3, 9.8.2.2.3, Fig. 9.8.7

h Minimum height of constricted bay sectionnear the pump

Fig. 9.8.2, Table 9.8.1

L Width of rectangular entrance for intakesuction piping

Fig. 9.8.18

L A characteristic length (usually bell diam-eter or submergence)

9.8.5.3, Eq. 9.8.5-1

L1 Distance between suction piping take-offs Fig. 9.8.22

L2 Distance from suction header or flow dis-turbing device to pump flange

Fig. 9.8.22

Lr Geometric scale of model Eq. 9.8.5-3, Eq. 9.8.5-4, Eq. 9.8.5-5

Lv Characteristic length of a cubic cage typevortex suppressor

A-6, Fig. A.12

NΓ Circulation number 9.8.7.2

n Revolutions/second of the swirl meter Eq. 9.8.5-6

n Manning’s n C-2.2, Tables C.1 and C.2

OD Outside diameter of pump bell or inlet bell Table 9.8.3

Q Flow 9.8.2.6.6, Table 9.8.3, Fig. 9.8.25, 9.8.7.2, 9.8.7.3,Fig. 9.8.26, B-2, Eq. B-1

Qm Flow scale in model Eq. 9.8.5-4

Qp Flow scale in prototype Eq. 9.8.5-4

Qr Flow scale ratio, model/prototype Eq. 9.8.5-4

Qin Inflow into sump or pump station B-2, Eq. B-1, Eq. B-2, Eq. B-3

Qp1 Flow rate for pump no. 1 or flow with onepump running

B-2, Eq. B-2, Fig. B.2, B-3




40

Qp2 Flow with two pumps running Fig. B.2, B-3

R Reynolds number 9.8.5.3

r Radius of curvature Fig. 9.8.3, 9.8.3.2.3, Fig. 9.8.13

r Radius of tangential velocity component 9.8.7.2

S Minimum submergence depth Foreword, Fig. 9.8.1, Eq. 9.8.2.1-2, 9.8.2.1.4,Table 9.8.1, 9.8.2.2.3, Fig. 9.8.3, 9.8.2.3.2.1,Fig. 9.8.4, Fig. 9.8.5, Fig. 9.8.6, Fig. 9.8.7, 9.8.2.5.4,Fig. 9.8.8, Fig. 9.8.12, 9.8.2.7.4, Fig. 9.8.13,Fig. 9.8.17, Fig. 9.8.18, 9.8.7.3, 9.8.7.2, 9.8.5,Eq. 9.8.7-1, Fig. 9.8.26

T Pump cycle time in minutes B-2, Eq. B-1, Eq. B-2, B-3

Tm Time scale of model Eq. 9.8.5-5

Tp Time scale of prototype Eq. 9.8.5-5

Tr Time scale ratio, model/prototype Eq. 9.8.5-5

u Average axial velocity (such as in thesuction bell)

9.8.5.3, Eq. 9.8.5-1

u Average axial velocity at the swirl meter Eq. 9.8.5-6

V Velocity Eq. 9.8.2.1-1, 9.8.2.1.4, 9.8.2.2.3, 9.8.2.5.4, 9.8.2.5.5,Fig. 9.8.9, Fig. 9.8.10, 9.8.2.7.4, 9.8.6, Table 9.8.3,Fig. 9.8.25, 9.8.7.2

Vol Effective sump volume B-2, Eq. B-1

Vol1 Active sump volume for pump no. 1 B-2, Eq. B-2, B-3

Vol2 Active sump volume for pump no. 2 B-3

VolTOT Total active volume of sump B-3

Vc Cross-flow velocity Fig. 9.8.1, Table 9.8.1

Vm Velocity scale in model Eq. 9.8.5-3

Vp Velocity scale in prototype Eq. 9.8.5-3

Vr Velocity scale ratio, model/prototype Eq. 9.8.5-3, Eq. 9.8.5-4, Eq. 9.8.5-5

vt Tangential velocity 9.8.7.2

Vx Pump bay velocity Fig. 9.8.1, Table 9.8.1

VT Vortex type 9.8.7.2

We Weber number 9.8.5.3

W Pump bay entrance width Fig. 9.8.1, Table 9.8.1, Fig. 9.8.2, Fig. 9.8.18

W Width of FSI 9.8.2.2.3, Fig. 9.8.3, Fig. 9.8.7

w Constricted bay width near the pump Fig. 9.8.2, Table 9.8.1

X Pump bay length Fig. 9.8.1, Table 9.8.1

Y Distance from pump inlet bell centerline totraveling screen

9.8.2.1.4, Fig. 9.8.1, Table 9.8.1

y Depth Table C.1, Table C.2

Z1 Distance from pump inlet bell centerline todiverging walls

Fig. 9.8.1, Table 9.8.1

Z2 Distance from pump inlet bell centerline tosloping floor

Fig. 9.8.1, Table 9.8.1




41

α Angle of floor slope Fig. 9.8.1, Table 9.8.1

β Angle of wall divergence 9.8.2.1.4, Fig. 9.8.1,Table 9.8.1

ε Angle of side wall of trench Fig. 9.8.13

ƒ A function 9.8.7.2

ρ Liquid density 9.8.5.3

Γ Circulation of the flow 9.8.5.3, 9.8.7.2

ν Kinematic viscosity of the liquid 9.8.5.3

θ Swirl angle Eq. 9.8.5-6

σ Surface tension of liquid/air interface 9.8.5.3

φ Angle of divergence from constricted areato bay walls

Fig. 9.8.2, Table 9.8.1




42

Appendix A

Remedial Measures for Problem Intakes

This appendix is not part of this standard, but is presented to help the user in considering factors beyond the stan-dard sump design.

A-1 Introduction

The material presented in Appendix A is provided forthe convenience of the intake design engineer in cor-recting unfavorable hydraulic conditions of existingintakes. None of the remedial measures describedherein are part of the standard intake design recom-mendations provided in Section 9.8. A portion of thematerial in Appendix A transmits general experienceand knowledge gained over many years of improvingthe hydraulics of intake structures, and such educa-tional material may not include the specific recommen-dations appropriate for a standard. Correctionsdescribed herein have been effective in the past, butmay or may not result in a significant improvement inperformance characteristics for a given set of site-specific conditions. Other remedial fixes not providedherein may also be effective, and a hydraulic modeltest is needed to verify whether a given remedialdesign feature results in acceptable flow conditions.This is particularly true because adding a remedialfeature to solve one flow problem may have detrimen-tal effects on other flow phenomena of concern.

Appendix A concentrates on rectangular intakes forclear liquids, but the basic principles can be applied toother types of intakes. The material is organized by thegeneral type of hydraulic problem in an upstream todownstream direction, since proper upstream flowconditions minimize downstream remedial changes.

A-2 Approach flow patterns

The characteristics of the flow approaching an intakestructure is one of the foremost considerations for thedesigner. Unfortunately, local ambient flow patternsare often difficult and expensive to characterize. Evenif known, conditions are generally unique, frequentlycomplex, so it is difficult to predict the effects of a givenset of flow conditions upstream from an intake struc-ture on flow patterns in the immediate vicinity of apump suction.

When determining direction and distribution of flow atthe entrance to a pump intake structure, the followingmust be considered:

• The orientation of the structure relative to the bodyof supply liquid

• Whether the structure is recessed from, flush with,or protrudes beyond the boundaries of the body ofsupply liquid

• Strength of currents in the body of supply liquid per-pendicular to the direction of approach to the pumps

• The number of pumps required and their antici-pated operating combinations

Velocity profiles entering pump bays can be skewed,regardless of whether cross-currents are present. Sev-eral typical approach flow conditions are shown in Fig-ure A.1 for rectangular intake structures withdrawingflow from both moving bodies of liquid and stationaryreservoirs. Figure A.2 shows several typical approachflow conditions for different combinations of pumpsoperating in a single intake structure.

The ideal conditions, and the assumptions upon whichthe geometry and dimensions recommended for rect-angular intake structures in this section are based, arethat the structure draws flow so that there are negligi-ble ambient currents (cross-flows) in the vicinity of theintake structure that create asymmetrical flow patternsapproaching any of the pumps, and the structure is ori-ented so that the boundary is symmetrical with respectto the centerline of the structure. As a general guide,cross-flow velocities are significant if they exceed 50%of the pump bay entrance velocity. Recommendations(based on a physical hydraulic model study) for ana-lyzing departures from the ideal condition are given inSection 9.8.5.

A-2.1 Open vs. partitioned structures

If multiple pumps are installed in a single intake struc-ture, dividing walls placed between the pumps result in



43

more favorable flow conditions than found in opensumps. Open sumps, with no dividing walls, have beenused with varying levels of success, but adverse flowpatterns can frequently occur if dividing walls are notused. The trench-type intake structure, described in

Section 9.8.2.4 and 9.8.3.2, is a type of open sumpthat is an exception. Open sumps are particularly sus-ceptible to cross-currents and non-uniform approach flowpatterns. Even if approach flow at the entrance to thestructure is uniform, open sumps result in non-uniform

a - One wall parallel, one wallperpendicular to direction of finalapproach

b - Straight approach, structurelocated at the terminus of a longcanal

c - Wing walls, with cross-currents d - Wing walls, with nocross-currents

e - No wing walls, with cross-currents f - No wing wall, with no cross-currents

Pump bay velocitydistribution

Figure A.1 — Examples of approach flow conditions at intake structures and the resulting effect on velocity, all pumps operating



44

flow patterns approaching some of the pumps whenoperating pumps are arranged asymmetrically withrespect to the centerline of the intake structure. Thissituation can occur when various combinations ofpumps are operating or if the intake structure isdesigned to accommodate additional pumps at somefuture date. Figure A.3 is an example of flowapproaching the pumps in both a partitioned structureand an open sump, both operating at partial flow rate.

The example facilities contain four units with two of thefour operating. In both structures, flow is withdrawn

from a reservoir with no velocity component perpen-dicular to the longitudinal centerline of the intake struc-tures. In the partitioned structure, flow enters the bayof pump 1 fairly uniformly. It enters the bay containingpump 2 non-uniformly, with a separation area near theright side-wall. However, the length of the bay relativeto its width channels the flow and allows it to becomemore uniform as it approaches the pump. In Figure A.3,example b, the dashed line at the wing walls shows arounded entrance configuration that minimizes flowseparation near the entrance to the outer pump bays.

Figure A.2 — Examples of pump approach flow patterns for various combinations of operating pumps



45

In open sumps (Figure A.3, example a), flow may enterthe structure uniformly with respect to the centerline ofthe structure. However, since the location of the twooperating pumps is not symmetrical with respect to thecenterline of the structure, flow separates from theright wall of the structure and approaches pump 2 witha tangential velocity component, greatly increasing theprobability of unacceptable levels of pre-swirl.

If all four pumps in the open sump were to operatesimultaneously, approach flow would be reasonablyuniform, but other adverse phenomena could bepresent. For example, when two adjacent pumps are

operating simultaneously, submerged vortices fre-quently form, connecting both pumps.

A-3 Controlling cross-flow

If cross-flow is present (i.e., if the pump station is with-drawing flow from the bank of a canal or stream), trashracks with elongated bars can provide some assis-tance in distribution flow as it enters the pump bay, butif the flow profile is skewed when it enters the trashrack, it will be skewed as it exits. To be effective inguiding flow, trash racks must be placed flush with theupstream edges of the pump bay dividing walls. In thisexample the trash rack must be vertical or match the

1 2 3 4

Flowseperation

line

1 2 3 4

a - Open sump, Pumps 1 & 2 operating illustrating problem flow patterns

Curved wall toprevent flowseperation atentrance

b - Partitioned sump, Pumps 1 & 2 operating, less likely to result in flow problems

Figure A.3 — Comparison of flow patterns in open and partitioned sumps



46

incline of the entrance. Both trash racks and dividingwalls must be in line with the stream bank contour.Trash racks recessed from the entrance to pump bays,and through-flow traveling screens have a negligibleflow straightening effect (see Figure A.4).

Partially clogged trash racks or screens can createseverely skewed flow profiles. If the application is suchthat screens or trash racks are susceptible to clogging,they must be inspected and cleaned as frequently asnecessary to prevent adverse effects on flow patterns.

Two other flow-straightening devices for minimizingcross-flow effects at bay entrances are shown in Fig-ure A.5. One or two large guide piers or plates per bayhelp turn the flow. Although distinct flow separationeddies occur at each pier, the eddies are smaller thanthe single flow separation (eddy) that would occuralong one bay wall. Alternatively, a number of smallercolumns or structural members may be placed at thebay entrance, and these are effective in both turning

and creating more uniform velocity by inducing a headloss across the column array.

A-4 Expanding concentrated flows

Two methods for correcting flow disturbances gener-ated by expansion of a concentrated flow aredescribed below.

A-4.1 Free-surface approach

In some installations, site conditions dictate that theapproach flow channel or conduit, although in line withthe sump axis, is much smaller than the sump width.To avoid concentrated flow and large eddies, the sidewalls approaching the pump bays must graduallydiverge, and flow baffles of varying geometry may beused to spread the flow at a divergence angle greaterthan otherwise possible. Figure A.6 shows possiblecorrective measures.

Flow separation line

Velocity distribution downstream from trash racks with cross flow

12" Min.

FLUSH RECESSED

Figure A.4 — Effect of trash rack design and location on velocity distribution entering pump bay

Figure A.5 — Flow-guiding devices at entrance to individual pump bays



47

The flow leaving a dual entry flow screen requires baf-fling to break up and laterally distribute the concen-trated flow prior to reaching the pump, and onepossible arrangement is shown in Figure A.7.

If measures are not taken to mitigate the effects thesescreens have on flow patterns (see Figure A.8), the jetexiting the center of these screens will attach to onewall or the other, and will result in highly non-uniformflow for an indefinite distance down the channel. Thenon-uniform flow creates excessive swirl at the pump.The screen exit must be placed a minimum distance ofsix bell diameters, 6D (see Section 9.8.2.1.3) from thepumps. However, this distance is only a general guide-

line for initial layouts of structures, with final design tobe developed with the aid of a physical model study.

A-4.2 Closed conduit approach

Flow may be provided to rectangular intake structuresthrough a conduit. When multiple pumps are installedperpendicularly to the influent conduit, the flow patternimproves and approach velocities decrease if thesump walls diverge gradually from the point of influenttoward the pump bays. Maintaining a small angledivergence of each wall from the influent conduit mini-mizes the difficulty in spreading the flow uniformly. Aseries of flow distribution baffles may be installed to

Approximate influent jetboundary (may not besymetrical)

Upwelling and laterialflow movement to outerpump bays

Radiallydiffused flowapproachingpumps

Vertical columnarray for flowdistribution

20°max.

IMPROVEDORIGINAL

Figure A.6 — Concentrated influent configuration, with and without flow distribution devices

NOTE: Physical hydraulic model study required.

Figure A.7 — Baffling to improve flow pattern downstream from dual flow screen



48

dissipate the energy of the entering flow and force adiverging and more uniform flow pattern approachingthe pumps. A typical approach flow pattern in a wetwell with a conduit approach, with and without diverg-ing side walls and flow distribution baffles, is shown inFigure A.7.

If a conduit approach is required and there is no roomfor gradually diverging side walls, velocities in the con-duit entering the sump may need to be limited, such asby adding expansion pieces to the downstream end ofthe conduit. In addition to the features describedabove, a baffle may be needed near the influent pointof the conduit(s) to dissipate the energy from theentering jet and spread the flow toward the pump bays.

Increasing the number of inflow lines together with aflow distributor across the sump and/or each bay mayprovide an adequate distribution to the pump bays,see Figure A.9.

The trench-type wet well described in Section 9.8.2.4is an alternate arrangement, where the pumps arepositioned in line with the approach pipe.

A-5 Pump inlet disturbances

A-5.1 Free-surface vortices

Surface vortices may be reduced with increasingdepth of submergence of the pump bells. However,

Unstable jetattaches toone side wall

Typical trashrack location

Screenbulkhead

Screenmesh

D

NOTE: Physical hydraulic model study required.

Figure A.8 — Typical flow pattern through a dual flow screen



49

there are also situations where increasing depth hasnegligible effects or even increases surface vortex for-mation due to stagnant and therefore unstable liquid.Surface vortices are also highly dependent onapproach flow patterns and the stability of these pat-terns, as well as on the inlet Froude number. Theabove situation complicates the establishment of aminimum depth of submergence as a definitive mea-sure against vortices. To achieve a higher degree ofcertainty that objectionable surface vortices do notform, modifications can be made to intake structuresto allow operation at practical depths of submergence.

Many pump manufacturers offer optional “suctionumbrellas” to reduce free surface vortices. Usually,suction umbrellas are horizontally oriented flat rings or“washers” attached to the pump bell to increase thebell diameter and reduce velocities at the revised inlet.

Curtain walls, such as shown in Figure A.10, create ahorizontal shear plane that is perpendicular to the ver-tical axis of rotation of surface vortices, and preventthe vortices from continuing into the inlet.

Move Back WallTo RecommendedClearance

Add Baffle

Add InflowPipe(s)

Add Increasers

Flow Distributor(s)

Figure A.9 — Improvements to approach flow without diverging sump walls

Min. LiquidLevel

1/2 D Min.

2DMin.

D

Figure A.10 — Elevation view of a curtain wall for minimizing surface vortices



50

Vertical curtain walls have been used with successand are easier to construct than sloping curtain walls.However, the abrupt changes in flow direction causedby vertical walls can create surface vortices in theupstream corners of those walls. If the curtain wallsare placed at about 45 degrees from the vertical, thenall flow near the surface is deflected downwards andsurface vortices are minimized. Curtain walls alsoassist in spreading poorly distributed flow.

Horizontal gratings may also be used to suppress freesurface vortices when pumping clear liquids. Standardfloor grating 38 mm (1.5 inches) deep or greater, or aspecially constructed “egg-crate” type grating may beeffective. At the low liquid level, the top of the gratingshould be submerged about 150 mm (6 inches). As atemporary measure, floating rafts of various types maybe used to suppress surface vortices.

A-5.2 Sub-surface vortices

The geometry of boundaries in the immediate vicinityof the pump bells is one of the more critical aspects ofsuccessful intake structure design. It is in this area thatthe most complicated flow patterns exist and flow mustmake the most changes in direction, while maintaininga constant acceleration into the pump bells to preventlocal flow separation, turbulence, and submerged vor-tex formation. Pump bell clearance from the floor andwalls is an integral part of the design. A sampling ofvarious devices to address sub-surface vortices areshown in Figure A.11. These and other measures maybe used individually or in combination to reduce theprobability of flow separation and submerged vortices.

A-5.3 Pre-swirl

Whether pre-swirl exists to an objectionable extent isgoverned primarily by the approach flow distribution. Asufficiently laterally skewed approach flow causesrotation around the pump bell, in spite of the local fea-tures. Such rotation causes flow over the central split-ter and potentially produces a submerged vortexemanating from the flow separation at the central split-ter. A cone on the floor would not cause such a sub-merged vortex problem, but the cone would also nothelp to control residual pre-swirl.

The most effective way of reducing pre-swirl is toestablish a relatively uniform approach flow withineach pump bay by using the baffling schemes dis-cussed in Sections A-2 to A-4 above. Final reductionsin swirl may be achieved near the pump bell by install-ing a vertical splitter along the back wall, in line anddirectly behind the pump column, by providing a hori-

zontal (sloping) floor splitter under the bell as shown inFigure A.11 and perhaps by using a submerged (weir)wall across the bay width, close to the upstream sideof the pump. This wall, if a few pump diameters highoff the floor, has the effect of turning all the flow down-ward, similar to that in a circular “can” arrangement,and the basic change in flow pattern may reduce pre-swirl and other undesirable hydraulic phenomena.

A-5.4 Velocities in pump bell throat

A relatively uniform velocity distribution occurs at thepump bell throat if the flow enters the bell essentiallyradially, without pre-swirl or local flow disturbancessuch as vortices or eddies caused by local flow sepa-ration. Therefore, all of the above described flow con-trol devices, starting with providing a uniform approachflow and including local anti-vortex measures near thebell, may be needed to achieve the desired uniformityof velocities.

Alternatively, a properly shaped formed suction intake(FSI) may be provided, as discussed in Section9.8.2.2. Model tests have shown that the FSI providesthe desired uniformity of velocity at the bell throat forreasonable flow patterns approaching the FSI.

A-6 Tanks — suction inlets

Undesirable flow conditions may be created at thepump inlet in the tank depending on the inflow–outflowarrangement in a storage tank, whether the tank inflowis operating while the pump suction (inlet) is operating,and whether there are flow obstructions in the tank.Even if only the pump inlet is operating and there areno flow obstructions in the tank, the non-uniformapproach flow to the pump inlet may cause pre-swirland vortices.

Since a dry-pit pump is usually located some distancedownstream from its piping inlet in the tank, the effectof these flow disturbances on the pump is not assevere as with wet-pit pumps. For example, local flowseparation, swirl, or velocity non-uniformities, althoughcreating greater head losses at the inlet, may be dissi-pated in the approach piping to the pump. The mainproblem is usually entrainment of air (or other tankgases) due to free-surface vortices, as this air may col-lect in the piping (causing air binding) or cause degra-dation of pump performance.

Preventing the formation of free-surface vortices attank inlets to pumps allows the tank to be drawn tolower levels than would otherwise be possible. Thisbenefit requires the use of various anti-vortex devices



51

A - Wall splitter plate B - Floor splitter plate C - Floor cone

E - Corner filletsD - Back wall F - Back wall fillet

H - Center splitterG - Side wall fillets I - Strainer withguide vanes

0.3D

2D

0.6D0.5D

0.5D 2D

0.5D 0.5D

0.5D

0.5D

Figure A.11 — Methods to reduce sub-surface vortices (examples A–I)



52

at the inlet. Some common types of such devices areshown in Figure A.12.

As an alternative, a cage type vortex suppressor maybe used, as illustrated in Figure A.12, example 6. Thecubic cage may be made of standard 38 mm(1.5 inches) deep (or deeper) floor grating (or itsequivalent). The length, width and height of the cubiccage, each with a characteristic length termed Lv

should be about 3 inlet pipe diameters, and the top ofthe cage should be submerged about 150 mm(6 inches) below the minimum liquid level. Non-cubiccage shapes are also effective if the upper (horizontal)grating is at least 3 inlet pipe diameters on each sideand is also submerged 150 mm (6 inches) below theminimum liquid level. A single horizontal grating meet-ing these guidelines may also be effective. Tests onsuch cage type vortex suppressors have demonstrated

Figure A.12 — Anti-vortex devices



53

their capability to reduce air entrainment to nearly zeroeven under adverse approach flow conditions (Pad-manabhan, 1982). However, it may be noted that theminimum submergence from the tank floor is dictatedby the vertical cage dimension plus the needed 150mm (6 inches) submergence above the top of thecage.



54

Appendix B

Sump Volume


B-1 Scope

This section on pump sump volumes pertains to con-stant speed pumps. For adjustable speed pumping,sump volume may not need to be considered (assum-ing certain pump controls) except for a requirementthat the sump volume must be large enough to keepcurrents sufficiently low.

B-2 General

Most pumping systems that transfer liquids (asopposed to circulating systems) utilize some form of apump sump. A pump sump acts as an intermediatebuffer zone capable of absorbing inflow fluctuationsrelative to pumping capacity. The pump sump is oftenused for intermediate storage to allow constant speedpumps to work in an on/off mode while the pump sumpis being filled and emptied. This operation allows forthe most efficient use of constant speed pumps. Apump sump should also act to distribute the inflow tothe various pumps in a pumping station in such a waythat good hydraulic inflow conditions exist at eachpump during various operating conditions.

In new construction as well as in upgrading existingpump stations, it is important to know the requiredactive sump volume. This volume is defined by thehighest start level and lowest stop level in the pumpsump. The minimum required sump volume can becalculated and it depends on the inflow to the pumpstation, the pump capacities, their allowed cycle time(number of starts per hour allowed for pump, drive,starters, etc., as applicable), and their operatingsequence. The limiting parameter is the cycle time.The volume has to be sufficiently large not to exceedthe number of starts per hour specified by the motor/pump manufacturer. For the simplest case (one pumpoperated at constant speed), the maximum number ofstarts per hour occurs when the inflow is 50% of thepump capacity. For multiple pumps, the operatingsequence also affects the volume required. The num-ber of starts per hour a pump and motor system cansustain is determined by the selection of startingequipment, load and inertia characteristics of the

pump, and the motor design. With increasing numbersof allowable starts per hour, the requirement for activesump volume is reduced. Alternating the startingpump in multiple pump installations also greatlyreduces the required active sump volume.

For pumping systems dealing with solids-bearing liq-uids, allowing the pump sump level to fluctuate will cre-ate differences in flow patterns that may minimizesolids sedimentation and particle build-up on theintake surfaces.

There are several methods to calculate the requiredactive sump volume. The sequence with which thepumps are brought on and off line plays an importantrole as does the total number of pumps. An activesump volume that is too small reduces motor, pump,and electrical equipment life by excessive starting andstopping. A pump station with a sump volume that istoo large is expensive to build, and the larger volumemay increase the risk of undesirable hydraulic patternsdue to stagnant zones and zones of low liquid velocity.For domestic sewage, the increased storage time pro-motes septicity during periods of low flow. Since anincrease in the active volume often is accomplished byconstructing a deeper station, a larger volume leads tohigher pumping head and consequently a higherenergy usage. In a situation where contaminated orsolids-bearing liquid is pumped, a larger pump sumpwould also be more difficult to maintain in a cleanstate.

To calculate the minimum sump volume for an applica-tion with constant speed pumps, start with the follow-ing relationship:

(B.1)

Where:

T = The pump cycle time in minutes, i.e., thetime between two consecutive starts (timeto fill and empty).

T VolQin--------- Vol

Q Qin–-------------------+

=



55

Vol = The effective sump volume, i.e., the vol-ume between the start level and the stoplevel in liters (cubic feet).

Qin = The inflow into the pump station in l/min(cubic feet per minute).

Q = The pump flow rate in l/min (cubic feet perminute).

Differentiating the equation shows that the maximumnumber of starts per hour occurs at an inflow ratewhich is half of the pumping rate.

Rearranging Equation B.1 and solving for Vol1:

(B.2)

Where:

Vol1 = The active sump volume for pump 1 inliters (cubic feet).

T = Pump cycle time (time to fill and empty) inminutes.

Qin = The inflow into the station in l/min (cubicfeet per minute).

QP1 = The flow rate of pump 1 in l/min (cubic feetper minute).

Two operational sequences for multi-pump stationsare:

The staggered stop levels in sequence 1 results in alower energy consumption, but may require a largeractive sump volume.

B-3 Minimum sump volume sequence

The required active sump volume and cycle time inrelation to pump capacity can be calculated by usingEquation B.1 in combination with the correspondingpump and system head curves.

When the second pump is brought on line, the flowrate in the system increases, thus producing increasedlosses. This scenario effectively reduces the capacityof each pump running (see Figure B.2).

Each volume must be calculated with the appropriatepump capacity.

Example B-1-A (A station with two duty plus onestandby pump) has three constant speed pumps, eachwith a capacity of 150 l/s (2400 gpm) at 15 m (50 ft),which is the first duty point on the system curve. Thesecond duty point is 250 l/s (4000 gpm) at 16.7 m(55 ft) (two pumps together). What is the minimumsump volume using sequence 1 operation and 10starts per hour?

Convert the pump flow rates to l/min (cfm), by multi-plying with 60 (7.48 gallons per cubic foot).

150 l/s = 9000 l/min (2400 gpm = 320 cfm)

250 l/s = 15,000 l/min (4000 gpm = 535 cfm)

The highest pump cycling frequency occurs when theinflow equals 50% of the pump flow with one pumprunning, therefore the Vol1 is determined for Qin = 5 l/s(159 cfm).

Pump Cycle Time 1 in Metric Units:

Vol2 is calculated with the following equation. An itera-tion or trial and error show that the shortest cycle timeoccurs for Qin = 200 l/s (424 cfm).

Sequence 1 The pumps start and stop at individ-ual levels; as the level rises in thesump, each pump is sequentiallybrought on-line until the inflow is sur-passed. As the level falls, eachpump is brought off line in reverseorder (see Figure B.1).

Sequence 2 The pumps start as in sequence 1,but all pumps continue to operate tothe minimum stop level (see FigureB.1).

Vol1 TQin

Qp1----------

Qp1 Qin–( )=

T 60 × 6010

-------------------- 360 seconds= =

Vol1 TQin

Qp1----------

Qp1 Qin–( )=

Vol1 360 75150----------

150 75–( )=

Vol1 13,500 liters=



56

Where:

QP2 = the flow with two pumps running

Thus, the minimum sump volume is:

Voltot = Vol1 + Vol2 = 22,500 liters

for this example.

In US Units:

Vol2 is calculated with the following equation. An itera-tion or trial and error show that the shortest cycle timeoccurs for Qin = 200 l/s (424 cfm).

Thus, the minimum sump volume is:Voltot = Vol1 + Vol2 = 802 cubic feet for this example.

Minimum Sump Volume Sequence 2

The pumps start as in sequence 1. The differencehere is that all pumps continue to run until the liquidreaches the low level shut off. The calculation for Vol1is the same as for sequence 1; however, the followingequation must be used for Vol2 (only for two pumps).

Where:

T = Pump cycle time in minutes.

Vol1 = Active sump volume for pump 1, liters(cu ft).

Sequence 1 Sequence 2

Start P2

Start P1

All Off

Stop P2

Stop P1

V2

V1

Start P2

Start P1

All Off Stop All

Figure B.1 — Operational sequences

HeadTotal head 1 pump running

System head

Total head2 pumps running

FlowQp2Qp1

HLoss

HStatic

Figure B.2 — Pump and system head curves

Vol2 T Qin Qp1–( )Qp2 Qin–( )Qp2 Qp1–( )

--------------------------------=

Vol2 360 200 150–( ) 250 200–( )250 320–( )

------------------------------=

Vol2 9000 liters=

T 6010------ 6 minutes= =

Vol1 TQin

Qp1----------

Qp1 Qin–( )=

Vol1 6 159318----------

318 159–( )=

Vol1 477 cubic feet=

Vol2 T Qin Qp1–( )Qp2 Qin–( )Qp2 Qp1–( )

--------------------------------=

Vol2 6 424 318–( ) 535 424–( )535 318–( )

------------------------------=

Vol2 325 cubic feet=

TVol1Qin

------------Vol2

Qin Qp1–-------------------------

Vol1 Vol2+

Qp2 Qin–------------------------------+ +

=



57

Vol2 = Active sump volume for pump 2, liters(cu ft).

Qin = The inflow into the station in l/min (cfm).

QP1 = Flow rate with pump 1 running, l/min (cfm).

QP2 = The combined flow rate with 2 pumps run-ning, l/min (cfm).

Rearranging:

(B.2)

An iteration or trial and error process is used to deter-mine that the shortest cycle time occurs when Qin =180 l/s (381 cfm). This inflow is used to calculate theminimum Vol2.

In Metric Units:

T = 360 seconds

Vol1 = 13,500 liters

Vol2 = 1,935 liters

VolTOT = Vol1 + Vol2 = 15,435 liters

In US Units:

T = 6 minutes

Vol1 = 477 cubic feet

Vol2 = 74 cubic feet

Total active volume is:VolTOT = Vol1 + Vol2 = 551 cubic feet

Thus, operational sequence 2 requires less active vol-ume than operational sequence 1.

B-4 Decreasing sump volume by pump alternation

By designing the control system for alternating pumpstarts, twice as many starts per hour (for a station withtwo operational pumps) can be obtained, reducing thesump volume by 50% and distributing the pump oper-ating time evenly between pumps. In a critical applica-tion, a two-pump station may have an installed sparepump in addition to the main pumps. Considerationshould be given to the system and application beforeutilizing this sump volume reduction technique.

Vol2T Qin Qp1–( ) Qp2 Qin–( )

Qp2 Qp1–-----------------------------------------------------------------=

–Vol1Qp2 Qin Qp1–( )

Qin Qp2 Qp1–( )------------------------------------------------------

Vol2360 180 150–( ) 250 180–( )

250 150–------------------------------------------------------------------------=

13,500 × 250 180 150–( )180 250 150–( )

------------------------------------------------------------------–

Vol26 381 318–( ) 535 381–( )

535 318–-----------------------------------------------------------------=

477 × 535 381 318–( )381 535 318–( )

----------------------------------------------------------–



58

Appendix C

Intake Basin Entrance Conditions


C-1 Variable speed pumps

There should be 5 to 10 diameters of straight, pris-matic, and level (or nearly level) inlet pipe leading intothe pump basin. The pipe should lie in a vertical planethrough the pump intakes. To avoid high currents nearthe pump intakes, the pipe should be well above thebasin floor, as shown in Figures 9.8.4, 9.8.5, 9.8.6,9.8.7, 9.8.13, and 9.8.17.

To produce uniform flow across the entrance of the wetwell during a cleaning, provide a short (approximatelyD/5) rectangular recess 2D wide on the upstream sideof the sluice gate. Alternately, use a short transitionfrom a circular pipe to a rectangular conduit as shownin Figure 9.8.13.

The minimum liquid level must be high enough to avoida free fall of the liquid entering the wet well. Becausethe speed of the pump can be regulated to match theinflow, a stable liquid level in the wet well can be main-tained to match the depth in the upstream conduit,thus avoiding a free fall.

C-2 Constant speed pumping

Constant speed pumping requires cyclic (on-off) pumpoperation, and there must be enough active storagevolume to keep the frequency of motor starts withinthe manufacturer’s recommendations. The active stor-age volume is obtained by allowing the liquid level tofluctuate - typically about 1.2 m (4 ft) for constantspeed pumping applications.

Improper but common practice is to allow a free fall orcascade from the inlet into the pool below. But even ashort free fall entrains air bubbles and drives themdeep into the pool where they may be drawn into thepumps and reduce pump flow rate, head, and effi-ciency as well as cause damage to the pump. If the liq-uid is domestic wastewater, the turbulence sweepsmalodorous and corrosive gasses into the atmo-sphere. The problem, in 1997, was almost universal inwet wells for constant speed pumps where the activestorage requirement made it necessary to separate

high and low liquid levels by, typically, 1.2 m (4 ft) toavoid excessively frequent motor starts.

C-2.1 Inlet pipe, trench-type wet wells

The objectives in designing the entrance for trench-type wet wells containing constant speed pumps are:

1) To eliminate any cascade

2) To minimize turbulence and the release ofnoxious dissolved gasses

3) To produce gentle, horizontal currents freefrom air bubbles

4) To supply a large part of the active storagevolume in the inlet pipe so as to minimize thesize of the wet well

Objectives 1 and 3 could be met by installing a dropmanhole 5 to 10 diameters upstream from the sluicegate. Objectives 2 and 4, however, would not be met;and a drop manhole is not recommended.

C-2.2 Storage in approach pipe

All four objectives listed in C-2.1 can be achieved byinstalling an “approach pipe,” a pipe somewhat largerthan the upstream sewer and laid at a severe gradientto produce supercritical velocities at low wet well levelsand thus supply a major share of the required activestorage volume. The last part of the approach pipeshould preferably be laid horizontally and must meetthe other conditions in C-1 above. A gradient of 2% isa good choice because:

1) A pipe 60 m (200 ft) long allows the liquid levelto fluctuate 1.2 m (4 ft)

2) Such a pipe can hold half or more of the activestorage volume required



59

3) supercritical velocities are reasonable andproduce a weak hydraulic jump where thesupercritical flow strikes the pooled water

The Froude number for the jump is less than 2.5, sothere is little bubble formation and off-gassing. Notefrom Tables C.1 and C.2 that the useful active storagecross-section of the approach pipe varies from 72 to81% of the total pipe cross-sectional area.

To flush deposits from the approach pipe, set the stoplevel for each pump (or combination of pumps) to pro-duce an approach pipe exit velocity of 1.0 to 1.2 m/s(3.0 to 4.0 ft/s).

Tables C.1 and C.2, developed by Wheeler (1995),contains data for approach pipes at 2% gradient basedon a modified Manning’s n of 0.010 (roughly equivalentto a constant n of 0.013). The allowable flow is predi-cated on a sequent depth (after the jump) of 60% of

the pipe diameter. The energy grade line (EGL) beforethe jump is about 25% of the pipe diameter (Dp) belowthe soffit, so the hydraulic jump can never reach thetop of the pipe. There is a 20 Dp length of free watersurface so that any bubbles formed in the hydraulicjump can rise to the surface and escape up the pipe.

Smoother pipes and steeper slopes generate highervelocities, larger Froude numbers upstream from thejump, and higher sequent depths than do flatter slopesor rougher pipe. To maintain a sequent depth of 60%of the pipe diameter, it follows that for a given size andslope, a rough approach pipe can carry a larger flowthan a smooth one.

C-3 Transition manhole, sewer to approach pipe

The transition in the manhole between the upstreamconduit and the approach pipe is designed to acceler-

Table C.1 — Maximum flow in approach pipes with hydraulic jump—metric units, slope = 2%, Manning’s n = 0.010a. Sequent depth = 60% pipe diameter. After Wheeler (1995).

a For n = 0.009, multiply flow rates by 92%.For n = 0.011, multiply flow rates by 108%.For n = 0.012, multiply flow rates by 115%.For n = 0.013, multiply flow rates by 122%.

True Pipe Flow Rate Before Jump After JumpDia.

DP mmAreaAt m2 m3/h l/s y/DP %b

b Depth (y) divided by pipe diameter (Dp) expressed in percent.

Velocitym/s Ae/At %c

c Empty area of pipe above liquid level (Ae) divided by total area (At).

FroudeNumber y/DP %b

EnergyLoss %

254 0.051 71 20 32 1.4 72 1.6 59 17

304 0.073 110 31 32 1.6 72 1.6 59 18

381 0.114 190 53 31 1.8 74 1.7 60 18

457 0.164 290 81 30 2.0 75 1.7 60 18

533 0.223 420 120 29 2.2 76 1.7 60 19

610 0.292 580 160 29 2.3 76 1.8 60 19

686 0.370 770 210 28 2.5 77 1.8 60 20

762 0.456 990 270 28 2.6 78 1.8 60 20

838 0.552 1200 340 27 2.8 78 1.9 60 20

914 0.657 1500 420 27 2.9 78 1.9 60 21

1067 0.894 2200 610 27 3.2 78 1.9 60 21

1219 1.17 3000 840 26 3.5 79 2.0 60 22

1372 1.48 4000 1100 26 3.7 79 2.0 60 22

1524 1.82 5100 1400 25 4.0 79 2.0 60 23

1676 2.21 6500 1800 25 4.2 81 2.1 60 23

1829 2.63 7900 2200 25 4.4 81 2.1 60 24



60

ate the liquid to the velocities in Tables C.1 and C.2.Care must be taken to form a sloping transitionbetween the invert of the upstream conduit or seweron one side and the invert of the approach pipe on theother side. The drop (and hence the slope) of the tran-sition invert can be found by the application of Ber-noulli’s Equation.

In the sewer, the EGL lies above the liquid surface bythe velocity head, v2/2g. For a sewer flowing full atmaximum design flow rate, the EGL is likely to besomewhat above the soffit. In the approach pipe, theEGL is 60% of the Dp plus velocity head above theinvert, and the sum is usually about 75% Dp.

Locate the approach pipe so that its EGL is below theEGL of the sewer by an amount equal to the expectedhead loss due to turbulence and friction. As data onhead losses are sparse, be conservative and increasethe invert drop somewhat to ensure supercritical flow.

Velocities 20% greater than the values in Tables C.1and C.2 increase the sequent depth from 60 to only67% Dp — an increase readily tolerated.

C-4 Sluice gate

A mechanically-operated sluice gate must be installedat the entrance to the wet well both to protect the sta-tion and to regulate the flow required for cleaning. Themechanism should be capable of setting the elevationof the sluice gate accurately and rapidly to a predeter-mined position.

C-5 Lining

The approach pipe is subject to corrosion caused bysulfuric acid forming above low liquid line by bacteriaacting upon sulfur compounds. As with the wet well, allsurfaces above low liquid level should be lined with animpervious material immune to corrosion.

Table C.2 — Maximum flow in approach pipes with hydraulic jump—US customary units, slope = 2%, Manning’s n = 0.010a. Sequent depth = 60% pipe diameter. After Wheeler (1995).

a For n = 0.009, multiply flow rates by 92%.For n = 0.011, multiply flow rates by 108%.For n = 0.012, multiply flow rates by 115%.For n = 0.013, multiply flow rates by 122%.

Pipe Flow Rate Before Jump After JumpDia.

DP inchAreaAt ft2 mgd ft3/s y/DP %b

b Depth (y) divided by pipe diameter (Dp).

Velocityft/s Ae/At %c

c Empty area of pipe above liquid level (Ae) divided by total area (At).

FroudeNumber y/DP %b

EnergyLoss %

10 0.55 0.5 0.7 32 4.6 72 1.6 59 17

12 0.79 0.7 1.1 32 5.1 72 1.6 59 18

15 1.23 1.2 1.9 31 5.8 74 1.7 60 18

18 1.77 1.9 2.9 30 6.5 75 1.7 60 18

21 2.41 2.7 4.1 29 7.1 76 1.7 60 19

24 3.14 3.7 5.7 29 7.7 76 1.8 60 19

27 3.98 4.9 7.5 28 8.2 77 1.8 60 20

30 4.91 6.3 9.7 28 8.7 78 1.8 60 20

33 5.94 7.8 12.1 27 9.2 78 1.9 60 20

36 7.07 9.7 14.9 27 9.7 78 1.9 60 21

42 9.62 14.0 21.6 27 10.6 78 1.9 60 21

48 12.6 19.1 29.6 26 11.4 79 2.0 60 22

54 15.9 25.3 39.1 26 12.2 79 2.0 60 22

60 19.6 32.5 50.3 25 13.0 79 2.0 60 23

66 23.8 40.9 63.3 25 13.7 81 2.1 60 23

72 28.3 50.3 77.8 25 14.4 81 2.1 60 24



61

C-6 Design examples

Examples of wet well designs for

1) Variable speed pumps

2) Constant speed pumps

3) Approach pipes

4) Transition manholes

are given by Sanks, Tchobanoglous, Bosserman, andJones (1998).

Tables C.1 and C.2 can be modified to other flows,pipe gradients, or roughness by means of the PART-FULL®‚ program (1995), which can be obtained freefrom Wheeler.



62

Appendix D

Bibliography


Section 9.8.2

Dicmas, J.L., “Vertical Turbine, Mixed Flow and Propel-ler Pumps,” McGraw-Hill Book Company.

U.S. Army Corps of Engineers (ETL No. 110-2-327).

Section 9.8.5

Anwar, H.O., Weller, J.A., and Amphlett, M.B., “Similar-ity of Free Vortex at Horizontal Intake,” Journal ofHydraulic Research, IAHR, Vol. 16, No. 2, 1978, p. 95.

Daggett, L., and Keulegan, G.H., “Similitude in Free-Surface Vortex Formations,” ASCE Journal of theHydraulics Division, Vol. 100, HY11, November 1974,p. 1565.

Hecker, G.E., “Model-Prototype Comparison of FreeSurface Vortices,” ASCE Journal of the HydraulicsDivision, Vol. 107, No. HY10, October 1981, p.1243.

Padmanabhan, M., and Hecker, G.E., “Scale Effects inPump Sump Models,” ASCE Journal of HydraulicEngineering, Vol. 110, No. 11, November 1984, p.1540.

Knauss, J., Coordinator-Editor, “Swirling Flow Prob-lems at Intakes,” IAHR Hydraulic Structures DesignManual 1., A.A. Balkema Publishers, Rotterdam, 1987.

Jain, A.K., Raju, K.G.R., and Garde, R.J., “Vortex For-mation at Vertical Pipe Intakes,” ASCE Journal ofHydraulics Division, Vol. 104, No. HY10, October1978, p. 1429.

Section 9.8.7

Hecker, G.E., Chapter 8, Conclusions, “Swirling FlowProblems at Intakes,” IAHR Hydraulic StructuresDesign Manual 1, J. Knauss, Coordinator-Editor, A.A.Balkema, Rotterdam, 1987.

Appendix A

Padamanabhan, M., Evaluation of Vortex Suppres-sors, Hydraulic Performance of Single Outlet Sumps,and Sensitivity of Miscellaneous Sump Parameters,Alden Research Laboratory Report No. 49A-82/M398F, September 1982.

Appendix C

Sanks, R.L., Tchobanoglous, G., Bosserman, B.E.,and Jones, G.M., Pumping Station Design, SecondEdition, Butterworth/Heinemann, 225 Wildwood Ave.,Woburn, MA 01801-2041, 1998.

Wheeler, W. PARTFULL®, 1995. (For a free copy of acomputer program for calculating maximum flow in anapproach pipe, with instructions, send a formatted1.4 MB, 3.5 disk and a self-addressed mailer to 683Limekiln Road, Doylestown, PA 18901-2335).


HI Pump Intake Design Index — 1998

63

Appendix E

Index

This appendix is not part of this standard, but is presented to help the user in considering factors beyond thisstandard.

Note: an f. indicates a figure, and a t. indicates a table.

Approach pipe lining, 60

Can intakesclosed bottom can, 13, 13f.design considerations, 11open bottom can intakes, 12, 12f.

Circular plan wet pits, 18, 18f., 19f.Circular pump stations (clear liquid)

dimensioning, 6floor clearance, 6inflow pipe, 7inlet bell clearance, 7inlet bell or volute diameter, 7sump diameter, 7, 7f., 8f.wall clearance, 6

Confined wet well design, 19, 20f.Constant speed pumps, 58, 59t., 60t.

Definitionssymbols, 38terminology, 35

Entrained air, 1

Flow, 26Formed suction intakes, 3, 6f.

application standards, 4dimensions, 3

Free-surface vortices, 1, 26, 26f.

Gas bubbles, 1Glossary, 35

Inlet bell design diameter, 21t., 28, 30f., 31f.Intake designs

alternative, 1design objectives, 1general information, 1

Intake structuresbasin entrance conditions, 58can intakes, 11circular plan wet pits, 18, 18f., 19f.circular pump stations (clear liquids), 5

for clear liquids, 1confined wet well design, 19, 20f.formed suction intakes, 3, 6f.model tests, 22rectangular intakes, 1, 3f., 4t., 5t.rectangular wet wells, 19remedial measures, 42for solids-bearing liquids, 15submersible vertical turbine pump intakes, 11, 14suction tanks, 9trench-type intakes (clear liquids), 7, 8f., 9f.trench-type wet wells, 16f., 17unconfined intakes, 14

Liquid level, 26

Model tests, 22acceptance criteria, 28flow, 26free-surface vortices, 26, 26f.instrumentation and measuring techniques, 26liquid level, 26model scope, 25objectives, 23pre-swirl, 27report preparation, 28similitude and scale selection, 24sub-surface vortices, 26f., 27swirl in the suction pipe, 27swirl meters, 27, 27f.test plan, 28velocity profiles, 27

Nomenclature, 38

Pre-swirl, 1, 27Pump suction piping, 20, 21f., 21t., 22f., 23f.Pumps

constant speed pumping, 58, 59t., 60t.hydraulic phenomena adversely affecting, 1sump volumes, 54variable speed, 58


HI Pump Intake Design Index — 1998

64

Rectangular intakesapproach flow patterns, 1design sequence, 5t.dimensioning, 2open vs. partitioned structures, 2trash racks and screens, 2

Rectangular wet wells, 19Remedial measures, 42

approach flow patterns, 42, 43f., 44f., 45f.cross-flow, 45, 46f.expansion of concentrated flows, 46, 47f., 48f., 49f.pump inlet disturbances, 48, 49f., 51f.suction tank inlets, 50, 52f.

Sluice gates, 60Submerged vortices, 1Submergence required for minimizing surface vortices,

29, 33f., 34f.Submersible vertical turbine pump intakes, 11, 14Sub-surface vortices, 26f., 27Suction tanks, 9

minimum submergence, 10, 10f., 11f.multiple inlets or outlets, 11NPSH considerations, 11simultaneous inflow and outflow, 11

Sump volumecalculating, 54decreasing by pump alternation, 57minimum sequence, 55operational sequences, 55, 56f.pump and system head curves, 55, 56f.

Surface vorticesrequired submergence for minimizing, 29, 33f., 34f.

Swirl, 1in the suction pipe, 27meters, 27, 27f.

Symbols, 38

Terminology, 35Transition manholes, 59Trench-type intakes, 7, 8f., 9f.

approach velocity, 9centerline spacing, 9end wall clearance, 9floor clearance, 9inlet conduit elevation, 9orientation, 9width, 9

Trench-type wet wells, 16f., 17

Unconfined intakes, 14cross-flow velocities and pump location, 15debris and screens, 15submergence, 15

Variable speed pumps, 58Velocity, 1Velocity profiles, 27Vortices, 1

free surface, 1, 26, 26f.required submergence for minimizing surface

vortices, 29, 33f., 34f.submerged, 1sub-surface, 26f., 27

Wet wells (solids-bearing liquids), 15cleaning procedures, 17confined inlets, 16trench-type, 16f.vertical transitions, 16wet well volume, 17




M123

9 Sylvan WayParsippany, New Jersey07054-3802 www.pumps.org

Master Indexfor Complete Set: ANSI/HI Pump Standards2002 Release



1

Hydraulic Institute Standards

Index of Complete Set: 2002 Release

This index is not part of any standard, but is presented to help the user in considering factors beyond the standards.

Note: Bold numbers indicate the standard number, non-bold numbers indicate the page number; an f. indiactes afigure, a t. indicates a table.

Abrasion, 9.1-9.5: 11severe, 9.1-9.5: 15

Abrasion resistant cast irons, 9.1-9.5: 19Acceleration head, 6.1-6.5: 25–27, 8.1-8.5: 12Acceleration pressure, 6.1-6.5: 25–27, 8.1-8.5: 12Accessory equipment, 3.1-3.5: 41–44Accumulator, 9.1-9.5: 3Acoustical calibration, 9.1-9.5: 50Actuating mechanism See Valve gearAdditives in liquid, 9.6.1: 4Adhesives, 9.1-9.5: 26Adjustment factors for alternate designs, 3.1-3.5: 42t.Affinity laws, 1.6: 16, 11.6: 28Air entrainment, 4.1-4.6: 20Air gap, 4.1-4.6: 7, 5.1-5.6: 12Airborne noise, 3.1-3.5: 28Airborne sound measurement, 9.1-9.5: 50

6 dB drop-off, 9.1-9.5: 50acoustical calibration, 9.1-9.5: 50averaging of readings, 9.1-9.5: 52A-weighted sound level, 9.1-9.5: 50, 51, 52background sound level and corrections, 9.1-9.5: 52,

54f.calculation and interpretation of readings,

9.1-9.5: 52caution (extraneous noise), 9.1-9.5: 51data presentation, 9.1-9.5: 52graphic plot, 9.1-9.5: 52instrumentation, 9.1-9.5: 50measurements and technique, 9.1-9.5: 51microphone locations, 9.1-9.5: 50, 51,54f.–60f.microphone system, 9.1-9.5: 50octave-band analyzer, 9.1-9.5: 50octave-band sound pressure levels, 9.1-9.5: 50, 51,

52operation of pumping equipment, 9.1-9.5: 50primary microphone location, 9.1-9.5: 51recorders, 9.1-9.5: 50reference sound source, 9.1-9.5: 50sound level meter, 9.1-9.5: 50test data tabulation, 9.1-9.5: 52test environment, 9.1-9.5: 50test reports, 9.1-9.5: 52, 53f.

Alarm limit (defined), 9.6.5: 2Alignment, 3.1-3.5: 36, 37f.

and elevated temperatures, 3.1-3.5: 38Alignment (horizontal pumps)

angular, 1.4: 3, 3f.and coupling guard, 1.4: 5dial indicator method, 1.4: 4, 4f.final, 1.4: 6of full pump, 1.4: 6of gear type couplings, 1.4: 4, 5f.laser method, 1.4: 4leveling pump and driver, 1.4: 2misalignment causes, 1.4: 13parallel, 1.4: 3, 3f.shaft and coupling, 1.4: 3of spacer type couplings, 1.4: 5, 5f.of special couplings, 1.4: 5straightedge method, 1.4: 3and thermal expansion, 1.4: 7of v-belt drive, 1.4: 5

Alignment (vertical pumps), 1.4: 9misalignment causes, 1.4: 13

All bronze pumps, 9.1-9.5: 16, 17All iron pumps, 9.1-9.5: 16, 17All stainless steel pumps, 9.1-9.5: 16, 17Alleviator, 9.1-9.5: 3Allowable operating range, 1.1-1.2: 58, 2.1-2.2: 22Allowable operating region, 9.6.3: 1

centrifugal pumps, 9.6.3: 5, 5f., 6f., 7f.factors affecting, 9.6.3: 1large boiler feed pumps, 9.6.3: 8vertical turbine pumps, 9.6.3: 8, 8t.

Alnico, 4.1-4.6: 8, 5.1-5.6: 14Aluminum and aluminum alloys, 9.1-9.5: 22Aluminum bronze, 9.1-9.5: 21American National Metric Council, 9.1-9.5: 7American Society for Testing and Materials, 9.1-9.5: 11Angular misalignment, 3.1-3.5: 36, 37, 37f., 38ANSI/ASME B73.1M, 9.6.2: 1, 3, 4, 5t., 6t., 7t.

1.5x1-8 CF8M (Type 316) pumpcombined axis deflection evaluation, 9.6.2: 25derating loads, 9.6.2: 22individual nozzle load evaluation, 9.6.2: 22

HI Index of Complete Set: 2002 Release

2

ANSI/ASME B73 (continued)individual nozzle load evaluation (new loads),

9.6.2: 23nozzle stress, bolt stress and pump slippage,

9.6.2: 23nozzle stress, bolt stress and pump slippage on

baseplate evaluation (new loads), 9.6.2: 24Y-axis deflection evaluation (new loads), 9.6.2: 24Z-axis deflection evaluation (new loads), 9.6.2: 24

3x1.5-13 Alloy 20 pumpcombined axis deflection evaluation, 9.6.2: 27derating loads, 9.6.2: 25nozzle stress, bolt stress and pump slippage,

9.6.2: 26Y-axis deflection evaluation, 9.6.2: 27Z-axis deflection evaluation, 9.6.2: 27

ANSI/ASME B73.2M, 9.6.2: 11ANSI/ASME B73.3M, 9.6.2: 1, 3, 4ANSI/ASME B73.5M, 9.6.2: 1, 3

1.5x1-8 pumpderating loads, 9.6.2: 28individual nozzle load evaluation, 9.6.2: 29

AOR See Allowable operating regionApparent viscosity, 3.1-3.5: 19, 6.1-6.5: 27, 9.1-9.5: 5Application guidelines, 5.1-5.6: 23–26, 8.1-8.5: 12Applications, 4.1-4.6: 11

factors in selecting rotary sealless pumps, 4.1-4.6: 12–16

stripping, 4.1-4.6: 15Approach pipe lining, 9.8: 60ASME B73.2M

4030/28 Alloy 20 pumpderating loads, 9.6.2: 31individual nozzle load evaluation, 9.6.2: 31

size 2015/17 CF8M (Type 316) pumpderating loads, 9.6.2: 30nozzle load evaluation, 9.6.2: 30

ASTM See American Society for Testing and MaterialsAtmospheric head, 1.1-1.2: 57, 1.6: 5, 2.1-2.2: 22,

2.6: 6, 11.6: 5Austenitic ductile iron, 9.1-9.5: 19Austenitic gray cast iron, 9.1-9.5: 18Auxiliary drive (steam) valve, 8.1-8.5: 4Auxiliary piping, 5.1-5.6: 22A-weighted sound level, 9.1-9.5: 50, 51, 52Axial flow impellers, 2.1-2.2: 3, 11f.Axial flow pumps, 1.1-1.2: 4, 4f.

impeller between bearings–separately coupled–single stage axial (horizontal) split case, 1.1-1.2: 46f.

impeller between bearings–separately coupled–single stage axial (horizontal) split case pump on base plate, 1.1-1.2: 45f.

separately coupled single stage–(horizontal) split case, 1.1-1.2: 16f.

separately coupled single stage–horizontal, 1.1-1.2: 15f.

separately coupled–mulitstage–(horizontal) split case, 1.1-1.2: 18f.

Axial load, 5.1-5.6: 13Axial split case pumps

casing hold-down bolts, 9.6.2: 15coordinate system, 9.6.2: 16f.driver and pump, 9.6.2: 15limiting factors, 9.6.2: 15nozzle loads, 9.6.2: 15, 16f.

Axial thrustcalculation, 2.3: 41f., 41terminology, 2.3: 40vs. rate of flow, 2.3: 42, 43f.with various impeller and shaft configurations,

2.3: 38, 38f., 39f., 40f.Axial thrust (for enclosed impellers for volute pump),

1.3: 60–63

Balancing See Rotor balancingBare rotor

multistage, axially split, single or double suction centrifugal pumps, 1.1-1.2: 25

single stage, axially (horizontally) split, single or double suction centrifugal pump, 1.1-1.2: 25

Barometric pressure, 6.1-6.5: 22, 23t., 8.1-8.5: 9and altitude, 8.1-8.5: 9, 10t.

Barrel or can (lineshaft) pumps, 2.1-2.2: 1, 8f.Barrel pumps See Can pumpsBaseline, 9.6.5: 1Baseplates (horizontal centrifugal pumps), 1.3: 78

defined, 1.3: 79exterior edges, 1.3: 85fasteners, 1.3: 81, 84free standing baseplate, 1.3: 79, 79f.functional requirements, 1.3: 79grout holes, 1.3: 84grouted baseplate, 1.3: 79, 79f., 85high-energy pump, 1.3: 79lifting base assembly, 1.3: 85motor mounting pads, 1.3: 80t., 81, 81f.mounting blocks, 1.3: 79, 85, 85f.mounting pads, 1.3: 79, 81f.mounting surface flatness, 1.3: 80t., 81, 81f.mounting surface height, 1.3: 80t., 81, 81f.rigidity, 1.3: 84shims, 1.3: 79f., 79, 81stress levels, 1.3: 81–84sub base, 1.3: 79f., 79, 85superstructure, 1.3: 79f., 79support and anchoring, 1.3: 86, 86f.tolerancing, 1.3: 80, 80t.torsional stiffness, 1.3: 86, 86f.

Bearing, 3.1-3.5: 4, 9.1-9.5: 3


3

Bearing failure mode causes and indicators, 9.6.5: 18, 21t.

Bearing life, 9.6.3: 2Bearing lubrication

comparison of stabilization temperature with manufacturer’s standards, 1.4: 12

measurement of operating temperature, 1.4: 11, 12f.rolling element bearings, 1.4: 11sleeve and tilting pad bearings, 1.4: 11sleeve bearings, 1.4: 12temperature vs. time, 1.4: 12

Bearing materials, 4.1-4.6: 15Bearing wear monitoring, 9.6.5: 14

acoustic detection, 9.6.5: 15bearing materials and characteristics, 9.6.5: 14carbon bearing wear characteristics, 9.6.5: 14contact detection, 9.6.5: 15contact or continuity switch, 9.6.5: 15control limits, 9.6.5: 15frequency, 9.6.5: 15indicators, 9.6.5: 24means, 9.6.5: 14power monitor, 9.6.5: 15silicon carbide bearing wear characteristics,

9.6.5: 14temperature probe, 9.6.5: 15vibration sensor, 9.6.5: 15wear detection methods, 9.6.5: 14

Bearingsadjusted rating life, 1.3: 74, 75axial load, 1.3: 74basic dynamic radial load rating, 1.3: 74basic rating life, 1.3: 74dynamic equivalent radial load, 1.3: 74external, 5.1-5.6: 19grease, 1.3: 65housing closures, 1.3: 70impeller mounted between, 1.3: 58, 72f.impeller overhung from, 1.3: 58, 70, 71f.internal, 5.1-5.6: 18labyrinths, 1.3: 70life, 1.3: 74lubrication, 1.3: 65–67oil lubrication, 1.3: 65operating temperature, 1.3: 75product lubrication, 1.3: 66t., 67radial load, 1.3: 74rating life, 1.3: 74reference and source material, 5.1-5.6: 38reliability, 1.3: 74rolling element, 1.3: 64, 64t.sleeve, 1.3: 64types, 1.3: 64

BEP See Best efficiency point

Best efficiency point, 1.1-1.2: 58, 1.3: 56, 1.6: 1, 2.1-2.2: 22, 2.3: 17, 2.6: 1, 9.6.1: 2, 9.6.3: 1, 11.6: 3

Body, 3.1-3.5: 4, 9.1-9.5: 3Boiler circulating pumps, 1.3: 10Boiler feed booster pumps, 1.3: 9Boiler feed pumps, 1.3: 8Bolt-proof load, 5.1-5.6: 15Booster service, 1.3: 1, 2.3: 1Bowl assembly efficiency, 2.1-2.2: 23, 2.6: 7

calculation, 2.6: 16Bowl assembly input power, 2.1-2.2: 23, 2.6: 7Bowl assembly output power, 2.6: 7Bowl assembly performance test, 2.6: 11, 11f.Bowl assembly total head, 2.1-2.2: 22, 2.6: 6

calculation, 2.6: 15measurement, 2.6: 29f., 29

Brassleaded red, 9.1-9.5: 20yellow, 9.1-9.5: 20

Bronzeall bronze pumps, 9.1-9.5: 16, 17aluminum, 9.1-9.5: 21leaded nickel bronze, 9.1-9.5: 21silicone, 9.1-9.5: 20specific composition bronze pumps, 9.1-9.5: 16, 17tin, 9.1-9.5: 20

Bronze fitted pumps, 9.1-9.5: 16, 17Building services pumping systems, 9.6.1: 9Bull ring packing, 6.1-6.5: 63, 63f.Burst disc (rupture), 9.1-9.5: 3Bushings, 1.4: 6Bypass, 1.4: 13Bypass piping, 9.1-9.5: 3

Calibrated electric meters and transformers, 1.6: 31Can intakes

closed bottom can, 9.8: 13, 13f.design considerations, 9.8: 11open bottom can intakes, 9.8: 12, 12f.

Can pumps, 2.3: 1, 3f.Can pumps See Barrel or can (lineshaft) pumpsCanned motor pumps, 5.1-5.6: 1

canned motor temperature, 5.1-5.6: 26close coupled end suction, 5.1-5.6: 1, 3f.close coupled in-line, 5.1-5.6: 1, 4f.defined, 5.1-5.6: 13driver sizing, 5.1-5.6: 25eddy currents, 5.1-5.6: 13horizontal mounting base, 5.1-5.6: 21induction motor, 5.1-5.6: 13integral motors, 5.1-5.6: 19location and foundation, 5.1-5.6: 32locked rotor torque, 5.1-5.6: 13


4

Canned motor pumps (continued)maintenance, 5.1-5.6: 35motor insulation, 5.1-5.6: 13motor winding integrity test, 5.1-5.6: 40motor winding temperature test, 5.1-5.6: 40separated pump and motor, 5.1-5.6: 1, 5f.starting torque, 5.1-5.6: 13submerged mounting, 5.1-5.6: 21vertical submerged canned motor pump, 5.1-5.6: 1,

6f.Canvas packing, 8.1-8.5: 17Capacity, 1.1-1.2: 55, 1.6: 3Capacity See Pump rate of flowCapacity See also Rate of flow (capacity)Carbon, 9.1-9.5: 26Carbon and low alloy steels, 9.1-9.5: 19Carbon steel, 9.1-9.5: 19Casing, 3.1-3.5: 4, 5.1-5.6: 18Casing rotation, 1.1-1.2: 26Casing types, 1.3: 76Casing working pressure, 1.1-1.2: 60Cavitation, 3.1-3.5: 23, 9.6.1: 3, 6, 10

damage factors, 9.6.1: 4Cavitation erosion resistance of, 9.1-9.5: 26, 28f.Centerline mounted pumps

separately coupled single stage, 1.1-1.2: 41f.separately coupled single stage (top suction),

1.1-1.2: 43f.separately coupled single stage–pump on base

plate, 1.1-1.2: 42f.separately coupled single stage–pump on base plate

(top suction), 1.1-1.2: 44f.Centerline support pumps, 1.1-1.2: 12f.Centipoises, 3.1-3.5: 19Centistokes, 3.1-3.5: 19Central stations, 2.3: 7Centrifugal and vertical pumps

sealed, 9.6.5: 1sealless, 9.6.5: 1

Centrifugal pump materials, 9.1-9.5: 16Centrifugal pumps, 1.4: 1

affinity laws, 11.6: 28defined, 1.1-1.2: 1horizontal pump installation, 1.4: 2–8maintenance, 1.4: 15nomenclature (alphabetical listing), 1.1-1.2: 27t.–

35t.nomenclature (numerical listing), 1.1-1.2: 35t.–38t.operation, 1.4: 10–15size, 1.1-1.2: 25vertical volute pump installation, 1.4: 8–10

Ceramics, 4.1-4.6: 8, 5.1-5.6: 13, 9.1-9.5: 26Check valve, 9.1-9.5: 3Chemical packings, 8.1-8.5: 17Chemical process pumps, 9.6.1: 6

Chemical pump, 1.3: 1Chromates, 9.1-9.5: 11Chromium coatings, 9.1-9.5: 23Chromium (ferric) stainless steel, 9.1-9.5: 20Chromium-nickel (austenitic) stainless steel,

9.1-9.5: 19CIMA See Construction Industry Manufactures

AssociationCircular casings, 1.3: 60, 60f.Circular plan wet pits, 9.8: 18, 18f., 19f.Circular pump stations (clear liquid)

dimensioning, 9.8: 6floor clearance, 9.8: 6inflow pipe, 9.8: 7inlet bell clearance, 9.8: 7inlet bell or volute diameter, 9.8: 7sump diameter, 9.8: 7, 7f., 8f.wall clearance, 9.8: 6

Circulation plans, 5.1-5.6: 21, 23, 24, 27f.–31f.Circumferential piston pumps, 3.1-3.5: 1f., 3f., 3Clean liquids, 5.1-5.6: 24Cleaning, 3.1-3.5: 33Close coupled (defined), 5.1-5.6: 12, 4.1-4.6: 7Close coupled–vane type magnetic drive pump,

4.1-4.6: 1, 2f.Closed feedwater cycle, 1.3: 6, 7f., 2.3: 9f., 9Closed lineshafts, 2.3: 43Closed suction tests, 2.6: 5, 5f., 6, 6f.CMP See Canned motor pumpCoating systems, 9.1-9.5: 22, 23–24Cobalt alloys, 9.1-9.5: 23Cobalt-chromium boron alloy, 9.1-9.5: 23Cobalt-chromium-tungsten alloy, 9.1-9.5: 23Coercive force, 4.1-4.6: 7Column, piping, 9.1-9.5: 3Compound gauge, 9.1-9.5: 3Computers and accessories (precautions), 5.1-5.6: 32Computers and computer storage and magnets,

4.1-4.6: 19Condensate pumps, 1.3: 9, 2.3: 9Condenser circulating water pumps, 1.3: 9, 2.3: 10Condition points, 1.1-1.2: 58, 2.1-2.2: 22Confined wet well design, 9.8: 19, 20f.Constant speed pumps, 9.8: 58, 59t., 60t.Construction, 2.1-2.2: 3, 6f.–12f.

parts listing, 2.1-2.2: 14t.–18t.Construction Industry Manufactures Association,

1.3: 13Containment

bolt-proof load, 5.1-5.6: 15driven component liner, 5.1-5.6: 14expectations, 5.1-5.6: 23maximum working pressure, 5.1-5.6: 15monitoring equipment, 5.1-5.6: 15secondary, 5.1-5.6: 15


5

suction pressure, 5.1-5.6: 15Containment shell, 4.1-4.6: 7, 12, 5.1-5.6: 14, 17

air in, 4.1-4.6: 20draining, 4.1-4.6: 21materials, 4.1-4.6: 15

Continuous service, 1.3: 42, 2.3: 17Contractors Pump Bureau, 1.3: 13Control limits, 9.6.5: 2Controlled volume pump materials, 9.1-9.5: 18Controls and alarms, 2.4: 8Cooling liquid flow, 4.1-4.6: 12

path, 4.1-4.6: 7Cooling towers, 9.6.1: 7Copper and copper alloys, 9.1-9.5: 20Copper-nickel alloys, 9.1-9.5: 21Correction factor K, 3.1-3.5: 41, 42t.Corrosion, 5.1-5.6: 20, 9.1-9.5: 11, 12

allowance for metallic centrifugal pumps, 1.3: 76in crevices, 9.1-9.5: 15galvanic, 9.1-9.5: 13, 14in pulp and paper applications, 1.3: 16severe, 9.1-9.5: 15

Corrosion failure mode causes and indicators, 9.6.5: 19t.

Corrosion monitoring, 9.6.5: 5control limits, 9.6.5: 6by electrical resistance, 9.6.5: 5frequency, 9.6.5: 6indicators, 9.6.5: 23by linear polarization resistance, 9.6.5: 6means, 9.6.5: 5by ultrasonic thickness measurement, 9.6.5: 6by visual/dimensional inspection, 9.6.5: 5

Corrosive properties of liquid, 9.6.1: 4Cost evaluation, 4.1-4.6: 16Coupling failure mode causes and indicators,

9.6.5: 19t.Couplings, 2.1-2.2: 13f., 3.1-3.5: 36, 38f., 4.1-4.6: 1

dimensions, 2.1-2.2: 13f.disk, 1.3: 68elastomer, 1.3: 68flexible, 1.3: 67gear, 1.3: 67limited end float, 1.3: 67offset, 1.3: 67selection, 4.1-4.6: 12speed limitations, 1.3: 68

Cover, 3.1-3.5: 4Cracking pressure, 3.1-3.5: 4Credit cards (precautions), 5.1-5.6: 32Credit cards and magnets, 4.1-4.6: 19Critical carrying velocity, 6.1-6.5: 27, 9.1-9.5: 5Critical speed

See Dry critical speedSee Lateral critical speed

Cross-sectional drawings, 2.1-2.2: 3, 6f.–12f.Cup type pistons

composition cups, 6.1-6.5: 64, 65f.installation, 6.1-6.5: 64–65synthetic rubber cups, 6.1-6.5: 64, 65f.

Curie temperature, 4.1-4.6: 7, 5.1-5.6: 14Cyclic service, 1.3: 42, 2.3: 17

D See DisplacementD See also Pump displacementD slide valves, 8.1-8.5: 4, 6f.Data packs, 9.1-9.5: 61Data sheet, 4.1-4.6: 18f.Data sheet for pump selection or design, 3.1-3.5: 29,

30f.–32f.Datum, 1.1-1.2: 55, 1.6: 3, 2.1-2.2: 19, 21f., 2.6: 3, 4f.,

3.1-3.5: 16, 3.6: 4, 6.6: 4, 11.6: 3Datum elevation, 1.1-1.2: 55f., 1.6: 3

horizontal pumps, 11.6: 3, 4f.horizontal units, 1.6: 3, 4f.vertical double suction pumps, 1.6: 3, 4f.vertical pumps, 11.6: 4, 4f.vertical single suction pumps, 1.6: 3, 4f.

Dead weight tester, 9.1-9.5: 3Deceleration devices, 1.3: 77, 2.3: 45Decontamination of returned products, 9.1-9.5: 61Decoupling, 4.1-4.6: 7, 5.1-5.6: 35

defined, 5.1-5.6: 14Deep well (lineshaft) pumps, 2.1-2.2: 1, 6f.Definitions, 3.1-3.5: 4–5, 4.1-4.6: 7–10, 5.1-5.6: 12,

6.1-6.5: 20–28, 8.1-8.5: 7, 9.1-9.5: 3–6symbols, 9.8: 38terminology, 9.8: 35

Deflection, 3.1-3.5: 40∆p See Differential pressure∆pmax See Maximum differential pressureDemagnetization, 4.1-4.6: 7, 20, 5.1-5.6: 14Dephase, 4.1-4.6: 7Design guidelines, 8.1-8.5: 12Design review, 9.6.5: 16

frequency, 9.6.5: 17hydraulic application review, 9.6.5: 16indicators, 9.6.5: 24installation review, 9.6.5: 17mechanical application review, 9.6.5: 16operating procedures review, 9.6.5: 17procedure, 9.6.5: 16

Dewatering service, 2.3: 4Dichromates, 9.1-9.5: 11Differential pressure, 3.1-3.5: 17, 3.6: 5, 11Diffusers, 1.3: 76Dilatant fluids, 3.1-3.5: 22Dimensional designations, 1.1-1.2: 39–46Dimensionally interchangeable pump, 1.1-1.2: 25,

2.1-2.2: 3


6

Direct acting (steam) pump materials, 9.1-9.5: 18Direct acting (steam) pumps

defined, 8.1-8.5: 1double-acting pump, 8.1-8.5: 1duplex pump, 8.1-8.5: 2horizontal pump, 8.1-8.5: 1inspection, 8.1-8.5: 22nomenclature, 8.1-8.5: 3piston pump, 8.1-8.5: 1f., 2simplex pump, 8.1-8.5: 2, 2f.types, 8.1-8.5: 1, 1f.typical services, 8.1-8.5: 12vertical pump, 8.1-8.5: 1

Direction of rotation, 3.1-3.5: 5Dirty liquids, 5.1-5.6: 24Discharge, 3.1-3.5: 33

insufficient, 2.4: 15lack of, 2.4: 15

Discharge flow, 5.1-5.6: 36Discharge piping, 2.4: 4, 6.1-6.5: 45, 46f.

See also Piping, Suction pipingair release valves, 2.4: 5lining up, 2.4: 3reducers, 2.4: 4f., 5siphons, 2.4: 6supports, anchors, and joints, 2.4: 4valves, 2.4: 5, 6f.

Discharge port, 3.1-3.5: 4, 9.1-9.5: 4Discharge pressure, 8.1-8.5: 7Discharge recirculation, 1.3: 43Discharge valve position, 1.4: 12Disk couplings, 1.3: 68Displacement, 3.1-3.5: 14, 3.6: 2, 6.1-6.5: 20,

8.1-8.5: 7Displacement type meters, 6.6: 13Dissolved gases, 3.1-3.5: 19, 21f.Double suction pump specific speed, 1.3: 32, 35f., 36f.Double volute casing See Dual volute casingDouble-acting pump, 6.1-6.5: 1, 2f., 3f.Dowelling, 1.4: 13Draining, 5.1-5.6: 18Drains, 8.1-8.5: 23Drive (steam) cylinder, 8.1-8.5: 4Drive (steam) end, 8.1-8.5: 3, 5f.

lubrication, 8.1-8.5: 15, 23Drive (steam) piston, 8.1-8.5: 4Drive characteristics, 4.1-4.6: 17Drive shaft, 1.3: 67Drive specification, 3.1-3.5: 24Driven component liner, 5.1-5.6: 14Driver mounting, 3.1-3.5: 34Driver sizing, 5.1-5.6: 25Drivers, 1.3: 76, 2.3: 45

deceleration devices, 1.3: 77, 2.3: 45electric motors, 1.3: 77, 2.3: 45

engines, 1.3: 77gears, 2.3: 45magnetic, 1.3: 77mounting and alignment, 2.4: 6non-reverse ratchets, 2.3: 46pre-lubrication, 2.4: 8pump-to-driver shafting, 2.3: 46steam turbine, 1.3: 77thrust bearings, 2.3: 46variable speed, 1.3: 77, 2.3: 45

Dry critical speed, 9.6.4: 2Dry vacuum test, 1.6: 25Dual volute casing, 1.3: 58, 59f., 76

K versus rate of flow, 1.3: 58, 59f.Ductile iron, 9.1-9.5: 18Duplex pump, 6.1-6.5: 2Duplex stainless steels, 9.1-9.5: 20Duplicate performance pump, 1.1-1.2: 25, 2.1-2.2: 3Duplicate pump, 2.1-2.2: 3Duty cycle, 3.1-3.5: 24Dynamic analysis report, 9.6.4: 4, 5Dynamic balance, 5.1-5.6: 20Dynamic balancing, 1.1-1.2: 61Dynamometers, 1.6: 30, 3.6: 18, 9.1-9.5: 3

calibration, 1.6: 31

Earthquake-resistance requirements, 2.4: 14Eccentric reducers, 2.4: 4, 4f.Economic consequences of failure, 9.6.5: 2Eddy currents, 4.1-4.6: 7, 5.1-5.6: 13, 17

drive, 4.1-4.6: 7, 5.1-5.6: 14drive coupling, 9.1-9.5: 3losses, 4.1-4.6: 7, 5.1-5.6: 14magnetic coupling, 4.1-4.6: 11

Effective particle diameter, 6.1-6.5: 27, 9.1-9.5: 5Efficiency, 1.3: 43, 2.6: 7, 5.1-5.6: 26, 6.1-6.5: 23,

11.6: 6best efficiency point (BEP), 1.3: 56calculation, 2.6: 15and high suction specific speed, 1.3: 53and impeller diameter trim, 1.3: 53and mechanical losses, 1.3: 53optimum, 1.3: 49prediction charts, 1.3: 49, 50f., 51f., 52f.prediction method for centrifugal pumps, 1.3: 49–57and pump type, 1.3: 56, 56t.and slurries, 1.3: 56and solids size, 1.3: 56and surface finish, 1.3: 53, 54f.tolerance at specified flow rate, 11.6: 9, 11.6: 10t.and viscosity, 1.3: 53and wear ring clearances, 1.3: 53, 55f.

Elastomer couplings, 1.3: 68Elastomeric polymers, 9.1-9.5: 24Electric driver input power, 1.6: 7, 2.6: 7


7

Electric motor input power, 1.1-1.2: 58, 2.1-2.2: 23Electric motors, 1.3: 77, 2.3: 45Electric power pumps, 9.6.1: 7Electrolytes, 9.1-9.5: 12Electronic instruments and magnets, 4.1-4.6: 19Electronic methods of speed measurement, 6.6: 18Elevation head, 1.1-1.2: 55, 1.6: 4, 2.1-2.2: 19, 2.6: 3,

4, 3.6: 4, 6.1-6.5: 22, 6.6: 4, 8.1-8.5: 9, 11.6: 4Elevation pressure, 3.1-3.5: 16, 3.6: 4, 6.1-6.5: 22,

6.6: 4, 8.1-8.5: 9Encapsulation, 4.1-4.6: 7End plate, 3.1-3.5: 4, 9.1-9.5: 3End suction pumps, 1.1-1.2: 4f.

submersible, 1.1-1.2: 5f.End suction slurry pumps, 9.6.2: 16Engines, 1.3: 77Entrained air, 2.4: 3, 4.1-4.6: 14, 20, 9.8: 1Entrained gases, 3.1-3.5: 19, 20f., 4.1-4.6: 14, 20Entrained, non-condensable gas, 5.1-5.6: 26Environmental consequences of failure, 9.6.5: 2Environmental considerations, 5.1-5.6: 24Equipment mounting drilling dimensions, 1.3: 87, 87f.Erosion, 9.1-9.5: 15

cavitation erosion resistance of materials, 9.1-9.5: 26, 28f.

Erosion failure mode causes and indicators, 9.6.5: 19t.η See Efficiencyηba See Bowl assembly efficiencyηmot See Submersible motor efficiencyηOA See Overall efficiencyηp See Pump efficiencyηp See Pump hydraulic efficiencyηp See Pump mechanical efficiencyηv See Pump volumetric efficiencyηv See Volumetric efficiencyηV See Volumetric efficiencyExcessive radial thrust, 1.3: 43Explosive atmosphere around magnets, 4.1-4.6: 19External bearings, 5.1-5.6: 19External couplings and guards, 5.1-5.6: 21External flush, 5.1-5.6: 25External gear and bearing screw pump on base plate,

3.1-3.5: 10f.External gear pumps

on base plate, 3.1-3.5: 9f.flanged ports, 3.1-3.5: 8f.threaded ports, 3.1-3.5: 8f.

Fabrics, 9.1-9.5: 26Face type seals, 3.1-3.5: 5Face-mounted motor dimensions, 1.1-1.2: 49t.

type JM, 1.1-1.2: 51t.type JM having rolling contact bearings, 1.1-1.2: 50f.type JP, 1.1-1.2: 52t.type JP having rolling contact bearings, 1.1-1.2: 50f.

Failure mode causes and indicators, 9.6.5: 1, 18t.FEA See Finite element analysisFerrite, 4.1-4.6: 8Field test pressure, 1.1-1.2: 60, 2.1-2.2: 25Field values

between bearing, single and multistage, 9.6.4: 17f.end suction foot mounted, 9.6.4: 9f.end suction, centerline support, 9.6.4: 13f.end suction, close coupled horizontal and vertical in-

line, 9.6.4: 11f.end suction, frame mounted, 9.6.4: 12f.end suction, hard metal and rubber-lined horizontal

and vertical, 9.6.4: 16f.end suction, paper stock, 9.6.4: 14f.end suction, solids handling, horizontal and vertical,

9.6.4: 15f.vertical in-line, separately coupled, 9.6.4: 10f.vertical turbine, mixed flow and propeller type,

9.6.4: 18f.vertical turbine, short set pumps, assembled for

shipment by the manufacturer, 9.6.4: 19f.Filter, 5.1-5.6: 13Finite element analysis, 9.6.4: 3, 5, 7Fire pumps, 1.3: 10, 2.3: 11First critical speed, 9.6.4: 1f., 1, 4First mode shape, 9.6.4: 4Fittings, 8.1-8.5: 14Flammability, 5.1-5.6: 24Flammable liquids or vapors, 8.1-8.5: 14Flange loads, 3.1-3.5: 40t., 41

correction factor K, 3.1-3.5: 41, 42t.Flanges, 8.1-8.5: 14Flexible couplings, 1.3: 67, 3.1-3.5: 36, 9.1-9.5: 3Flexible member pumps, 3.1-3.5: 1f., 2, 2f.Flooded suction, 6.1-6.5: 25, 8.1-8.5: 10Flow, 9.8: 26Flow monitoring See Rate of flow monitoringFlow rate, 6.1-6.5: 20, 11.6: 3Flow rate check, 1.4: 13Flow rate tolerance at specified total head, 11.6: 9, 10t.Fluid drive, 9.1-9.5: 3Fluidborne noise, 3.1-3.5: 27, 28Fluids, 3.1-3.5: 4, 33

dilatant, 3.1-3.5: 22miscellaneous properties, 3.1-3.5: 24Newtonian, 3.1-3.5: 19non-Newtonian, 3.1-3.5: 22plastic, 3.1-3.5: 22pseudo-plastic, 3.1-3.5: 22rheopectic, 3.1-3.5: 22thixotropic, 3.1-3.5: 22time-independent non-Newtonian, 3.1-3.5: 22

Flushing and filling, 2.4: 9Flux, 4.1-4.6: 7

density, 4.1-4.6: 7


8

Foot valves, 3.1-3.5: 41, 9.1-9.5: 3Force and mass requirements, 1.4: 1Formed suction intakes, 9.8: 3, 6f.

application standards, 9.8: 4dimensions, 9.8: 3

Foundation, 2.3: 45, 3.1-3.5: 34, 6.1-6.5: 55bolts, 1.4: 1, 2f., 3.1-3.5: 34, 34f., 6.1-6.5: 56, 56f.requirements, 1.4: 1, 2.4: 2typical bolt design, 2.4: 2f.

Frame mounted pumpsANSI B73.1, 1.1-1.2: 13f.lined, 1.1-1.2: 11f.separately coupled single stage–mixed flow,

1.1-1.2: 21f.separately coupled single stage–self-priming,

1.1-1.2: 24f.separately coupled–single stage, 1.1-1.2: 10f., 39f.separately coupled–single stage (vertically

mounted), 1.1-1.2: 47f.separately coupled–single stage–pump on base

plate, 1.1-1.2: 40f.Francis vane, 1.1-1.2: 3f., 3Free-surface vortices, 9.8: 1, 26, 26f.Frequency-responsive devices, 1.6: 31, 6.6: 18Friction characteristic, 6.1-6.5: 27, 9.1-9.5: 5Friction factor, 3.6: 17Friction head, 1.1-1.2: 57, 2.1-2.2: 22Friction loss pressure, 6.1-6.5: 23Full-flow bypass pressure, 3.1-3.5: 5Fully suspended solids, 9.1-9.5: 5

Galvanic corrosion, 9.1-9.5: 13minimizing, 9.1-9.5: 14

Galvanic series, 9.1-9.5: 13Gap, 4.1-4.6: 7Gap See Air gap, Liquid gap, Total gapGas, 2.3: 21

effect on performance, 2.3: 21, 21f.Gas See Liquids with vapor or gasGas bubbles, 9.8: 1Gas content, 9.6.1: 4Gaskets, 5.1-5.6: 18, 8.1-8.5: 15Gauge head, 1.1-1.2: 55, 1.6: 4, 2.1-2.2: 19, 2.6: 3,

11.6: 4Gauge pressure, 3.6: 4, 6.1-6.5: 22, 6.6: 4, 8.1-8.5: 9Gauss, 4.1-4.6: 8Gear couplings, 1.3: 67Gear pumps, 3.1-3.5: 1f., 2, 3f., 6f.–10f.Gears, 2.3: 45General purpose service, 1.3: 13–15Gilbert, 4.1-4.6: 8Gland, 3.1-3.5: 5Gland follower, 3.1-3.5: 5Gland, packing, 9.1-9.5: 3Glossary, 9.8: 35

Graphic level recorders, 9.1-9.5: 50Graphite, 5.1-5.6: 13, 9.1-9.5: 26Gray cast iron, 9.1-9.5: 18Grouting, 2.4: 3, 3.1-3.5: 35, 36f.

horizontal pumps, 1.4: 5vertical volute pumps, 1.4: 8

h See HeadH See Total headh See Headhatm See Atmospheric headhd See Total discharge headhg See Gauge headhs See Total suction headhv See Velocity headH See Total headhacc See Acceleration headhatm See Atmospheric headHba See Bowl assembly total headhd See Pump total discharge headhd See Total discharge headhf See Friction headhg See Gauge headhs See Total suction headhv See Velocity headHalide, 9.1-9.5: 11Handling equipment, 1.4: 1Hands and fingers (precautions), 5.1-5.6: 32Hardware terms, 9.1-9.5: 3Hazardous chemicals, 9.1-9.5: 61Hazardous materials, 5.1-5.6: 32Head, 1.1-1.2: 55, 1.6: 3, 2.1-2.2: 19, 2.6: 3,

3.1-3.5: 4, 11.6: 4atmospheric, 1.1-1.2: 57elevation, 1.1-1.2: 55friction, 1.1-1.2: 57gauge, 1.1-1.2: 55loop manifold connecting pressure taps, 1.6: 30f.measurement, 1.6: 29, 2.6: 27–31measurement by gauge/valve arrangement,

2.6: 28f., 28measurement by means of pressure gauges, 1.6: 30measurement by multiple tap connections, 2.6: 28,

28f.measurement by pressure gauges, 2.6: 29measurement by single tap connection, 2.6: 28, 28f.measurement with bourdon gauge below

atmospheric pressure, 2.6: 30, 30f.measurement with fluid gauge below atmospheric

pressure, 2.6: 30, 30f.net positive suction head available, 1.1-1.2: 58net positive suction head required, 1.1-1.2: 58pressure tap location for level A tests, 1.6: 29, 29f.pressure tap location for level B tests, 1.6: 29, 30f.single tap connection, 1.6: 29f.


9

total, 1.1-1.2: 57, 59total discharge, 1.1-1.2: 57total suction (closed suction), 1.1-1.2: 57total suction (open suction), 1.1-1.2: 57velocity, 1.1-1.2: 55

Head rate of flow curvecentrifugal pumps, 9.6.3: 4vertical pumps, 9.6.3: 4, 4f.

Head type rate meters, 6.6: 13, 14f.pressure tap opening, 6.6: 14, 14f.

Heat exchanger, 9.1-9.5: 3Heater drain pumps, 1.3: 10, 2.3: 11Hermetic integrity test, 4.1-4.6: 24, 5.1-5.6: 39Heterogeneous mixture, 6.1-6.5: 27, 9.1-9.5: 5High alloy steels, 9.1-9.5: 19High copper alloys, 9.1-9.5: 20High silicon cast irons, 9.1-9.5: 19High temperature, 5.1-5.6: 24High viscosity, 4.1-4.6: 13, 5.1-5.6: 25High-energy pumps, 1.1-1.2: 59, 59f., 60f., 2.1-2.2: 23,

24f.Hollow/solid shaft driver, 2.1-2.2: 2, 6f., 9f., 10f., 11f.Homogeneous flow, 6.1-6.5: 27, 9.1-9.5: 5Homogeneous mixture, 6.1-6.5: 27, 9.1-9.5: 5Horizontal end suction pumps

adjustment factors, 9.6.2: 4, 9t.allowable combination nozzle loads, 9.6.2: 6t., 7t.allowable individual nozzle loads, 9.6.2: 5t.alternate pump mounting, 9.6.2: 3driver/pump coupling alignment, 9.6.2: 2grouted nonmetal baseplate, 9.6.2: 4internal pump distortion, 9.6.2: 2material specifications, 9.6.2: 8t.nomenclature, 9.6.2: 1, 2f.nozzle load adjustment factors, 9.6.2: 3nozzle loads, 9.6.2: 1, 5t., 6t., 7t.nozzle stress, 9.6.2: 2pressure-temperature, 9.6.2: 2pump hold down bolts, 9.6.2: 2pump mounting, 9.6.2: 2spring-mounted metal baseplate, 9.6.2: 4stilt-mounted metal baseplate, 9.6.2: 3temperature and material adjustment factors,

9.6.2: 4ungrouted metal baseplate, 9.6.2: 3ungrouted nonmetal baseplate, 9.6.2: 4

Horizontal mounting base, 5.1-5.6: 21Horizontal pump, 6.1-6.5: 1f., 1Horizontal pump installation

alignment, 1.4: 2alignment of gear type couplings, 1.4: 4, 5f.alignment of spacer type couplings, 1.4: 5, 5f.alignment of special couplings, 1.4: 5angular alignment, 1.4: 3, 3f.controls and alarms, 1.4: 8

coupling guard, 1.4: 5dial indicator method of alignment, 1.4: 4, 4f.final alignment, 1.4: 6final alignment check, 1.4: 6full pump alignment, 1.4: 6grouting, 1.4: 5laser method of alignment, 1.4: 4leveling pump and driver, 1.4: 2, 2f.parallel alignment, 1.4: 3, 3f.pre-run lubrication, 1.4: 7shaft and coupling alignment, 1.4: 3straightedge method of alignment, 1.4: 3stuffing-box bushings, 1.4: 6stuffing-box mechanical seals, 1.4: 6stuffing-box packing, 1.4: 5stuffing-box steps, 1.4: 5suction and discharge pipes, 1.4: 7thermal expansion and alignment, 1.4: 7v-belt drive, 1.4: 5

Horsepower limit, 9.6.3: 3Hot oil pump, 1.3: 1Housing, 3.1-3.5: 4HP and HPH vertical solid-shaft motor dimensions,

1.1-1.2: 53f., 53t., 54t.HPRT See Hydraulic power recover turbinesHydraulic action, 8.1-8.5: 15Hydraulic disturbances, 9.6.4: 24Hydraulic drag, 4.1-4.6: 8Hydraulic failure mode causes and indicators,

9.6.5: 20t.Hydraulic hammer, 1.3: 22

See also Water hammer analysisHydraulic load balance, 5.1-5.6: 13Hydraulic parasitic losses, 4.1-4.6: 8Hydraulic piston packing, 8.1-8.5: 17

applications, 8.1-8.5: 17fitting, 8.1-8.5: 18, 18f.joint types, 8.1-8.5: 17, 18f.

Hydraulic power recover turbines, 2.3: 12Hydraulic pressure pump, 1.3: 14Hydraulic resonance See ResonanceHydraulic sizing, 5.1-5.6: 25Hydraulic slip, 4.1-4.6: 10Hydraulic turbines, pumps used as See Pumps used as

hydraulic turbinesHydrocarbon physical properties, 6.1-6.5: 50t., 51t.Hydrostatic test, 1.6: 7, 2.6: 1, 3.6: 13

assembled pump, 6.6: 10assembled pumps, 3.6: 13components, 3.6: 13, 6.6: 10duration, 6.6: 10objective, 1.6: 7, 2.6: 8, 6.6: 10parameters, 1.6: 8, 2.6: 8, 6.6: 10procedure, 1.6: 8, 2.6: 8, 6.6: 11records, 1.6: 8, 2.6: 9, 3.6: 13, 6.6: 11


10

Hydrostatic test (continued)temperature, 6.6: 10test liquid, 6.6: 10

Hydrostatic test pressure, 4.1-4.6: 8Hydrostatic tests. See Submersible pump hydrostatic

testHysteresis, 4.1-4.6: 8

Identical performance and dimensional pump, 1.1-1.2: 25

Identical pump, 2.1-2.2: 3Impeller balancing, 1.1-1.2: 60Impeller between bearings, 1.1-1.2: 1f., 2

separately coupled–multistage axial (horizontal) split case, 1.1-1.2: 18f.

separately coupled–multistage radial (vertical) split case, 1.1-1.2: 19f.

separately coupled–multistage radial (vertical) split–double casing, 1.1-1.2: 20f.

separately coupled–single stage axial (horizontal) split case, 1.1-1.2: 46f.

separately coupled–single stage axial (horizontal) split case pump on base plate, 1.1-1.2: 45f.

separately coupled–single stage–axial (horizontal) split case, 1.1-1.2: 16f.

separately coupled–single stage–radial (vertical) split case, 1.1-1.2: 17f.

Impeller designs, 1.1-1.2: 2axial flow, 1.1-1.2: 4, 4f.Francis vane, 1.1-1.2: 3f., 3impeller between bearing type, 1.1-1.2: 1f., 2mixed flow, 1.1-1.2: 3, 3f.radial flow, 1.1-1.2: 3, 3f.specific speed, 1.1-1.2: 3f.suction specific speed, 1.1-1.2: 3f.

Impeller eye diameter, 9.6.1: 3, 9.6.1: 4Impeller material, 9.6.1: 4Impeller vanes

incidence angle, 9.6.1: 2overlap, 9.6.1: 2f., 9.6.1: 2

Impellers, 1.3: 57, 75See also Overhung impeller pumpsaxial flow, 2.1-2.2: 3, 11f.axial thrust for volute pump, 1.3: 60–63with back ring, 1.3: 62f.balancing, 2.1-2.2: 25and bearing arrangements, 1.3: 58diameter change and pump performance, 2.3: 16,

16f.double suction, 1.3: 75dynamic balancing, 2.1-2.2: 25enclosed, 1.3: 76, 2.3: 44enclosed with plain back shroud, 1.3: 61f.with inducers, 2.3: 44, 44f.mixed flow, 2.1-2.2: 3, 10f.

modified radial flow, 2.1-2.2: 3, 10f.mounted between bearings, 1.3: 58, 72f.open, 1.3: 76open (axial flow), 2.3: 44overhung, 1.3: 58, 70, 71f.predicting pump performance after diameter change,

1.3: 48, 49f.pressure distribution on enclosed impeller shrouds,

1.3: 60f.profiles, 2.1-2.2: 2, 5f.pump characteristic curves, 2.1-2.2: 5f.radial flow, 2.1-2.2: 3semi-open, 1.3: 76, 2.3: 44single plane balancing, 2.1-2.2: 25single suction, 1.3: 75specific speed, 2.1-2.2: 2static balancing, 2.1-2.2: 25top suction, 1.3: 20, 21f.two plane balancing, 2.1-2.2: 25types, 1.3: 75, 2.3: 44various configurations and axial thrust, 2.3: 38, 38f.,

39f., 40f.venting the eye of, 1.3: 20, 21f.wear ring arrangements, 2.1-2.2: 12f.

Indicators, 9.6.5: 1, 22Induced eddy currents, 5.1-5.6: 17Inducers, 1.3: 20, 57, 57f., 2.3: 44, 44f.Induction motor, 5.1-5.6: 13Industrial plant, 2.3: 7Industrial pumps, 9.6.1: 9Inert gas sniffer test, 4.1-4.6: 24Inlet, 3.1-3.5: 4, 33, 9.1-9.5: 3Inlet bell design diameter, 9.8: 21t., 28, 30f., 31f.Inlet boosters, 1.3: 20Inlet geometry, 9.6.1: 2Inlet piping geometry, 9.6.1: 2Inlet port, 9.1-9.5: 3Inlet pressure, 3.1-3.5: 17, 3.6: 5Inlet system, 6.1-6.5: 38–40

booster pumps, 6.1-6.5: 40connection of piping sections, 6.1-6.5: 39f.foot valve, 6.1-6.5: 40high points in piping system, 6.1-6.5: 39inlet line valve, 6.1-6.5: 40inlet piping, 6.1-6.5: 40inlet piping diameters, 6.1-6.5: 39, 40f.inlet pressure gauge, 6.1-6.5: 40liquid source features, 6.1-6.5: 38multiple-pump installations, 6.1-6.5: 39pulsation dampener, 6.1-6.5: 41screens or strainers, 6.1-6.5: 40, 40f.suction system relationships, 6.1-6.5: 41, 42f., 43f.suction tanks, 6.1-6.5: 38f., 41

In-line pumps, 1.1-1.2: 7f.flexible coupling, 1.1-1.2: 8f.


11

rigid coupling, 1.1-1.2: 9f.Inner magnet assembly, 4.1-4.6: 8, 12Inner magnet ring, 5.1-5.6: 14Inside-adjustable lost-motion valve gear, 8.1-8.5: 6f.Inside-fixed lost-motion valve gear, 8.1-8.5: 6f.Inspection, 5.1-5.6: 32, 6.1-6.5: 65–66Inspection (pre-installation), 2.4: 1Inspection (shipment), 3.1-3.5: 33Inspection frequency, 4.1-4.6: 21Installation, 2.4: 2, 3.1-3.5: 33, 4.1-4.6: 19,

6.1-6.5: 56, 8.1-8.5: 14See also Maintenance, Operation, Troubleshootingaccessory equipment, 3.1-3.5: 41–44adjustment factors for alternate designs,

3.1-3.5: 42t.alignment, 3.1-3.5: 36, 37f., 5.1-5.6: 33auxiliary connections and monitoring devices,

5.1-5.6: 33bearings, 6.1-6.5: 60cleaning, 3.1-3.5: 33coupling alignment, 5.1-5.6: 33couplings, 3.1-3.5: 36, 38f.drive alignment, 6.1-6.5: 57driver mounting, 3.1-3.5: 34and entrained air, 2.4: 3flanges and fittings, 6.1-6.5: 57flexible coupling, 6.1-6.5: 58foot valves, 3.1-3.5: 41forces and moments, 6.1-6.5: 57foundation, 3.1-3.5: 34foundation bolts, 3.1-3.5: 34, 34f.gaskets, 6.1-6.5: 58gear drive, 6.1-6.5: 58grouting, 2.4: 3, 3.1-3.5: 35, 36f.handling equipment, 2.4: 1horizontal pumps, 1.4: 2–8inlet piping, 3.1-3.5: 39jacket piping, 3.1-3.5: 39leveling, 3.1-3.5: 35, 36f.leveling the unit, 5.1-5.6: 33, 6.1-6.5: 56limiting forces and moments for steel pumps,

3.1-3.5: 39, 40t., 42t.lining up pump discharge, 2.4: 3location, 3.1-3.5: 33location and foundation, 5.1-5.6: 32lubrication, 6.1-6.5: 60nozzle loads and criteria, 3.1-3.5: 39, 40t., 42t.outlet piping, 3.1-3.5: 39pipe dope and tape, 6.1-6.5: 58pipe-to-pump alignment, 3.1-3.5: 39f., 39piping, 3.1-3.5: 38, 5.1-5.6: 33, 6.1-6.5: 56piston rod packing, 6.1-6.5: 60–64pit dimensional checks, 2.4: 3priming, 6.1-6.5: 57procedure, 5.1-5.6: 32

protective devices, 3.1-3.5: 43pump leveling and plumbness, 2.4: 3, 3f.pump location, 2.4: 3relief valve set pressure, 6.1-6.5: 57, 58t.relief valves, 3.1-3.5: 43rotation check, 3.1-3.5: 35strainers, 3.1-3.5: 42tools, 1.4: 1, 2.4: 1V-belt drive, 6.1-6.5: 59, 59t., 60t., 60f.v-belts and sheaves, 3.1-3.5: 38, 38f.vertical volute pump, 1.4: 8–10well inspection, 2.4: 2wells, 2.4: 2, 2f.

Instrument calibration intervals, 3.6: 20, 21f.Instrumentation

calibration interval, 6.6: 18, 19t.fluctuation, 6.6: 6performance test, 6.6: 6

Instrumentation options, 5.1-5.6: 22Intake designs, 1.3: 57

alternative, 9.8: 1design objectives, 9.8: 1general information, 9.8: 1

Intake structuresbasin entrance conditions, 9.8: 58can intakes, 9.8: 11circular plan wet pits, 9.8: 18, 18f., 19f.circular pump stations (clear liquids), 9.8: 5for clear liquids, 9.8: 1confined wet well design, 9.8: 19, 20f.formed suction intakes, 9.8: 3, 6f.model tests, 9.8: 22rectangular intakes, 9.8: 1, 3f., 4t., 5t.rectangular wet wells, 9.8: 19remedial measures, 9.8: 42for solids-bearing liquids, 9.8: 15submersible vertical turbine pump intakes, 9.8: 11,

14suction tanks, 9.8: 9trench-type intakes (clear liquids), 9.8: 7, 8f., 9f.trench-type wet wells, 9.8: 16f., 17unconfined intakes, 9.8: 14

Intake system design, 2.3: 46Integral motors, 5.1-5.6: 19Integrity tests. See Submersible motor integrity testsInterchangeable pump, 1.1-1.2: 25, 2.1-2.2: 3Intermediate input power, 3.6: 6Intermediate mechanism efficiency, 3.6: 6Intermittent service, 1.3: 42, 2.3: 17Internal bearings, 5.1-5.6: 18Internal gear pumps

close coupled, 3.1-3.5: 7f.flange mounting, 3.1-3.5: 6f.foot mounting, 3.1-3.5: 6f.frame mounting, 3.1-3.5: 7f.


12

Internal mechanical contact, 9.6.3: 2Internal sleeve bearings, 4.1-4.6: 12Intrinsic induction, 4.1-4.6: 8Iron

abrasion resistant cast irons, 9.1-9.5: 19all iron pumps, 9.1-9.5: 16, 17austenitic gray cast iron, 9.1-9.5: 18ductile, 9.1-9.5: 18gray cast iron, 9.1-9.5: 18high silicon cast irons, 9.1-9.5: 19malleable cast iron, 9.1-9.5: 18nickel-chromium-iron alloys, 9.1-9.5: 21

Irrigation service, 1.3: 4, 2.3: 6

Jacketed pump, 3.1-3.5: 5, 9.1-9.5: 3Joint bolting, 5.1-5.6: 18

K See Correction factor KKinetic pumps, 9.1-9.5: 1, 2f.

impeller between bearing type, 1.1-1.2: 1f., 2overhung impeller types, 1.1-1.2: 1f., 2, 4f.–15f.,

21f., 24f.regenerative turbine type, 1.1-1.2: 1, 1f., 2special variations, 1.1-1.2: 2types, 1.1-1.2: 1f., 1

ls See Static suction liftL See StrokeLantern ring, 3.1-3.5: 5, 9.1-9.5: 3Lateral critical speed, 9.6.4: 1, 1f.

calculations, 9.6.4: 1Lateral dynamic analysis, 9.6.4: 3Lead and lead alloys, 9.1-9.5: 23Leaded nickel bronze (nickel silvers), 9.1-9.5: 21Leaded red brass, 9.1-9.5: 20Leak check, 1.4: 13, 2.4: 11Leak detection, 9.6.5: 6

control limits, 9.6.5: 7double-walled protection, 9.6.5: 7by flow increase, 9.6.5: 7frequency, 9.6.5: 7indicators, 9.6.5: 23means, 9.6.5: 6by sniffer inspection, 9.6.5: 6by visual inspection, 9.6.5: 6

Leakage detectionby flow increase, 9.6.5: 7by pressure buildup, 9.6.5: 7by sniffer inspection, 9.6.5: 7by visual inspection, 9.6.5: 7

Leather, 9.1-9.5: 26Legal requirements, 5.1-5.6: 24Letter designations, 1.1-1.2: 39–46Leveling, 3.1-3.5: 35, 36f.Life cycle cost analysis, 4.1-4.6: 16

Limited end float couplings, 1.3: 67Lineshafts, 2.3: 43Lip seal, 9.1-9.5: 3Liquid

classification, 4.1-4.6: 14gap, 4.1-4.6: 7lubricating, 4.1-4.6: 14non-lubricating, 4.1-4.6: 14prevention of operation without liquid flow,

4.1-4.6: 19properties, 4.1-4.6: 13pumped liquid characteristics, 4.1-4.6: 17shear sensitivity, 4.1-4.6: 15vapor pressure, 4.1-4.6: 14

Liquid bypass, 6.1-6.5: 35, 36f.Liquid end, 5.1-5.6: 12, 8.1-8.5: 1f., 3

cylinder liner, 6.1-6.5: 5, 11f.gland, 6.1-6.5: 7, 7f.lantern ring (seal cage), 6.1-6.5: 7, 7f.liquid cylinder, 6.1-6.5: 5, 5f.manifolds, 6.1-6.5: 5, 5f.packing, 6.1-6.5: 7, 7f.parts, 6.1-6.5: 5–8, 9f., 10f., 11f., 12t.piston, 6.1-6.5: 5, 6f.plunger, 6.1-6.5: 3f., 6, 7f.stuffing box, 6.1-6.5: 7, 7f.upper crosshead, 6.1-6.5: 8, 8f.valve assembly, 6.1-6.5: 8, 8f.valve chest cover, 6.1-6.5: 5, 11f.valve plate (check valve), 6.1-6.5: 5, 11f.

Liquid expansion factor, 6.1-6.5: 50, 51f.Liquid gap, 5.1-5.6: 12Liquid level, 9.8: 26Liquid velocity in casing throat, 9.6.3: 3Liquids, 3.1-3.5: 4, 33

chemical symbols, 9.1-9.5: 11clean, 5.1-5.6: 24common polymer materials for, 9.1-9.5: 37, 38t.containment shells, 5.1-5.6: 17dirty, 5.1-5.6: 24effects of temperature and concentration, 9.1-9.5: 11entrained gases in, 3.1-3.5: 19, 20f.high temperature, 9.1-9.5: 11, 12identification and properties, 3.1-3.5: 18low temperature, 9.1-9.5: 11, 12material selection for maximum continuous

temperature of various liquids, 9.1-9.5: 39, 40t.–44t., 45t.–49t.

materials commonly used for pumping, 9.1-9.5: 27, 29t.–37t.

specific gravity, 9.1-9.5: 11that solidify, 5.1-5.6: 24toxicity ratings, 5.1-5.6: 23types, 3.1-3.5: 18volatile, 5.1-5.6: 24


13

Liquids with vapor or gas, 1.3: 19–21effect of gas on performance, 1.3: 19, 20f.inducers (inlet boosters), 1.3: 20special designs for, 1.3: 20, 21f.top suction impeller, 1.3: 20, 21f.venting the eye of the impeller, 1.3: 20, 21f.

Lobe pumps, 3.1-3.5: 1f., 2, 2f., 12f.Location, 3.1-3.5: 33Location of unit, 1.4: 2Locked rotor torque, 5.1-5.6: 13Locked-rotor torque ratings, 6.1-6.5: 38, 39t.Long-term storage, 1.4: 1Losses, 2.3: 33Low alloy steels, 9.1-9.5: 19Low viscosity, 4.1-4.6: 13Low-energy pumps, 1.1-1.2: 59, 59f., 60f.Lubricant analysis, 9.6.5: 9

control limits, 9.6.5: 11evaluating wear rates, 9.6.5: 10indicators, 9.6.5: 23measuring contamination of lubricant, 9.6.5: 10measuring inorganic contamination, 9.6.5: 10measuring lubricant degradation, 9.6.5: 10measuring metal particles from wear, 9.6.5: 9measuring organic contamination, 9.6.5: 10monitoring frequency, 9.6.5: 11sampling techniques, 9.6.5: 11

Lubricating liquid, 4.1-4.6: 14Lubrication, 3.1-3.5: 44, 8.1-8.5: 15Lubrication and cooling, 5.1-5.6: 12

Magnet tape and magnets, 4.1-4.6: 19Magnetic couplings, 4.1-4.6: 8, 5.1-5.6: 14, 19Magnetic drive and driver sizing, 5.1-5.6: 25Magnetic drive configurations, 4.1-4.6: 1, 2f., 3f., 4f.Magnetic drive pump, 5.1-5.6: 2

alignment, 5.1-5.6: 33alnico, 5.1-5.6: 14close coupled, 5.1-5.6: 2, 8f.coupling alignment, 5.1-5.6: 33Curie temperature, 5.1-5.6: 14decoupling, 5.1-5.6: 14, 35defined, 5.1-5.6: 13demagnetization, 5.1-5.6: 14eddy current drive, 5.1-5.6: 14eddy current losses, 5.1-5.6: 14external bearings, 5.1-5.6: 19external couplings and guards, 5.1-5.6: 21inner magnet ring, 5.1-5.6: 14location and foundation, 5.1-5.6: 32magnetic couplings, 5.1-5.6: 14, 19magnetic drive and driver sizing, 5.1-5.6: 25magnets, 5.1-5.6: 14maintenance, 5.1-5.6: 35mounting base, 5.1-5.6: 21

neodymium, 5.1-5.6: 14outer magnet ring, 5.1-5.6: 14pole (N-S), 5.1-5.6: 14precautions, 5.1-5.6: 32rows of magnets, 5.1-5.6: 14samarium cobalt, 5.1-5.6: 14separately coupled, 5.1-5.6: 2, 7f.shipping precautions, 5.1-5.6: 32slip, 5.1-5.6: 14vertical submerged, 5.1-5.6: 2, 9f.

Magnetic drives, 1.3: 77Magnetic Material Producers Association, 4.1-4.6: 23Magnetic materials, 4.1-4.6: 8Magnetic slip, 4.1-4.6: 9Magnets, 5.1-5.6: 14

assembly, 4.1-4.6: 12assembly caution, 4.1-4.6: 21cautions, 4.1-4.6: 19, 21, 22component temperature, 5.1-5.6: 26demagnetization, 4.1-4.6: 20handling cautions, 4.1-4.6: 22humidity effects, 4.1-4.6: 21installation and safety considerations, 4.1-4.6: 19permanent, 4.1-4.6: 8shipping, 4.1-4.6: 19temperature limits, 4.1-4.6: 20, 5.1-5.6: 26

Main drive (steam) slide valve, 8.1-8.5: 4Main drive (steam) valves, 8.1-8.5: 4, 6f.

setting (duplex pumps), 8.1-8.5: 22setting (simplex pumps), 8.1-8.5: 23

Maintenance, 2.4: 14, 4.1-4.6: 21–22, 5.1-5.6: 32, 35access, 1.4: 1, 2.4: 2canned motor, 5.1-5.6: 35close running fits, 5.1-5.6: 35examination of wear patterns, 5.1-5.6: 36excessive power consumption, 1.4: 16inspections, 5.1-5.6: 35insufficient discharge flow or pressure, 1.4: 16little or no discharge flow, 1.4: 16loss of suction, 1.4: 16magnet assembly, 5.1-5.6: 35mechanical seals, 3.1-3.5: 46noise, 1.4: 15packing, 3.1-3.5: 46parts replacements, 2.4: 14preventive, 3.1-3.5: 45spare parts, 3.1-3.5: 46troubleshooting, 1.4: 15, 2.4: 15wear plates, 1.4: 15wear rings, 1.4: 15, 2.4: 14

Maintenance inspection, 9.6.5: 12characteristics to consider, 9.6.5: 12coupling flexible elements inspection, 9.6.5: 12erosion inspection, 9.6.5: 13frequency, 9.6.5: 13


14

Maintenance inspection (continued)hydraulic performance, 9.6.5: 13indicators, 9.6.5: 24key/keyways inspection, 9.6.5: 12shaft bending fatigue inspection, 9.6.5: 12shaft torsional fatigue inspection, 9.6.5: 13torsional overload inspection, 9.6.5: 13

Malfunction causes and remedies, 3.1-3.5: 46, 47t.–49t., 6.1-6.5: 66, 66t.–68t., 8.1-8.5: 23, 24t.

Malleable cast iron, 9.1-9.5: 18Manufacturer’s erecting engineer, 1.4: 1Manufacturer’s instructions, 1.4: 1, 2.4: 1Manufacturer’s service personnel, 2.4: 1Material Safety Data Sheets, 9.1-9.5: 61Materials, 4.1-4.6: 15, 5.1-5.6: 20

abrasion resistant cast irons, 9.1-9.5: 19adhesives, 9.1-9.5: 26aluminum and aluminum alloys, 9.1-9.5: 22aluminum bronze, 9.1-9.5: 21austenitic ductile iron, 9.1-9.5: 19austenitic gray cast iron, 9.1-9.5: 18carbon, 9.1-9.5: 26carbon and low alloy steels, 9.1-9.5: 19carbon steel, 9.1-9.5: 19cavitation erosion resistance of, 9.1-9.5: 26, 28f.centrifugal pumps, 9.1-9.5: 16ceramics, 9.1-9.5: 26chemical and physical properties, 9.1-9.5: 12chromium coatings, 9.1-9.5: 23chromium (ferric) stainless steel, 9.1-9.5: 20chromium-nickel (austenitic) stainless steel,

9.1-9.5: 19coating systems, 9.1-9.5: 22, 23–24cobalt alloys, 9.1-9.5: 23cobalt-chromium-tungsten alloy, 9.1-9.5: 23common polymer for various liquids, 9.1-9.5: 37, 38t.controlled volume pumps, 9.1-9.5: 18copper and copper alloys, 9.1-9.5: 20copper-nickel alloys, 9.1-9.5: 21and crevice corrosion, 9.1-9.5: 15direct acting (steam) pumps, 9.1-9.5: 18ductile iron, 9.1-9.5: 18duplex stainless steels, 9.1-9.5: 20elastomeric polymers, 9.1-9.5: 24fabrics, 9.1-9.5: 26factors affecting selection, 9.1-9.5: 11–16galling resistance, 9.1-9.5: 15and galvanic corrosion, 9.1-9.5: 13, 14and galvanic series, 9.1-9.5: 13and general design, 9.1-9.5: 12general designations by pump type, 9.1-9.5: 16–18graphite, 9.1-9.5: 26gray cast iron, 9.1-9.5: 18high alloy steels, 9.1-9.5: 19high copper alloys, 9.1-9.5: 20

high silicon cast irons, 9.1-9.5: 19lead and lead alloys, 9.1-9.5: 23leaded nickel bronze (nickel silvers), 9.1-9.5: 21leaded red brass, 9.1-9.5: 20leather, 9.1-9.5: 26and liquid temperature, 9.1-9.5: 12, 39, 40t.–44t.,

45t.–49t.and liquids, 9.1-9.5: 11low alloy steels, 9.1-9.5: 19malleable cast iron, 9.1-9.5: 18and mechanical situation in pumping, 9.1-9.5: 15microstructure of metals, 9.1-9.5: 15nickel alloys, 9.1-9.5: 21nickel copper alloys, 9.1-9.5: 21nickel or cobalt-chromium boron alloy, 9.1-9.5: 23nickel-chromium-iron alloys, 9.1-9.5: 21nickel-molybdenum alloys, 9.1-9.5: 21nickel-molybdenum-chromium alloys, 9.1-9.5: 21non-metal, 9.1-9.5: 24–26optimizing life cost, 9.1-9.5: 12power pumps, 9.1-9.5: 18reciprocating pumps, 9.1-9.5: 18reinforced fibers, 9.1-9.5: 26rigid polymers and composites, 9.1-9.5: 25rotary pumps, 9.1-9.5: 17sealants, 9.1-9.5: 26selection, 5.1-5.6: 25and severe corrosion or abrasion, 9.1-9.5: 15silicon bronze, 9.1-9.5: 20and thermal or hydraulic shock, 9.1-9.5: 16thermoplastics, 9.1-9.5: 25thermosetting polymers, 9.1-9.5: 25tin bronze, 9.1-9.5: 20tin-base bearing metals, 9.1-9.5: 23titanium alloys, 9.1-9.5: 23used for pumping various liquids, 9.1-9.5: 27, 29t.–

37t.and velocity effects, 9.1-9.5: 16vertical pumps, 9.1-9.5: 16for wetted pump parts, 9.1-9.5: 11yellow brass, 9.1-9.5: 20zinc and zinc alloys, 9.1-9.5: 23zirconium, 9.1-9.5: 23

Maximum allowable casing working pressure, 1.1-1.2: 60, 2.1-2.2: 23

Maximum allowable inlet working pressure, 3.1-3.5: 17, 3.6: 5

Maximum allowable working pressure, 3.1-3.5: 17, 3.6: 5

Maximum differential pressure, 3.1-3.5: 17, 3.6: 5Maximum discharge pressure, 2.1-2.2: 25Maximum suction pressure, 1.1-1.2: 58, 60,

2.1-2.2: 22Maximum working pressure, 4.1-4.6: 9, 5.1-5.6: 15Maxwell, 4.1-4.6: 8


15

MDP See Magnetic drive pumpMeasurement of airborne sound See Airborne sound

measurementMechanical integrity test, 5.1-5.6: 40Mechanical seal chamber, 9.1-9.5: 4Mechanical seal gland, 9.1-9.5: 4Mechanical seals, 1.3: 68, 1.4: 6, 3.1-3.5: 5, 46,

9.1-9.5: 3applications, 1.3: 68classifications, 1.3: 68, 69f.typical schematics, 1.3: 68

Mechanical test, 1.6: 23, 2.6: 1, 22acceptance levels, 1.6: 24, 2.6: 23instrumentation, 1.6: 23, 2.6: 23objective, 1.6: 23, 2.6: 22operating conditions, 1.6: 23, 2.6: 23procedure, 1.6: 23, 2.6: 23records, 1.6: 24, 2.6: 24setup, 1.6: 23, 2.6: 22temperature instruments, 1.6: 23vibration instruments, 1.6: 23

Metallic-type piston packing, 8.1-8.5: 19application, 8.1-8.5: 19clearance, 8.1-8.5: 19joints, 8.1-8.5: 18f., 19material, 8.1-8.5: 19maximum temperature for ring materials,

8.1-8.5: 19t.Metals

galling resistance, 9.1-9.5: 15microstructure, 9.1-9.5: 15

Metering efficiency, 3.6: 2Metric units, 9.1-9.5: 7

conversion factors, 9.1-9.5: 8t.–10t.rounded equivalents, 9.1-9.5: 7t.

Microphone locations (airborne sound measurement), 9.1-9.5: 50

axially split case centrifugal pump, 9.1-9.5: 55f.axially split case multistage centrifugal pump,

9.1-9.5: 57f.double case centrifugal pump, 9.1-9.5: 56f.horizontal end suction centrifugal pump, 9.1-9.5: 54f.horizontal reciprocating pump, 9.1-9.5: 57f.horizontal rotary gear pump, 9.1-9.5: 59f.horizontal rotary screw pump, 9.1-9.5: 59f.primary, 9.1-9.5: 51vertical in-line centrifugal pump, 9.1-9.5: 55f.vertical reciprocating pump, 9.1-9.5: 58f.vertical rotary pump, 9.1-9.5: 60f.

Microphone systems, 9.1-9.5: 50Mine dewatering, 1.3: 4Minimum flow, 1.3: 43Minimum spares, 1.1-1.2: 27Miscellaneous mechanical problems, 9.6.4: 24

Mixed flow impellers, 2.1-2.2: 3, 10f.Mixed flow pumps, 1.1-1.2: 3, 3f.Model tests, 1.6: 32, 2.6: 32, 9.8: 22

acceptance criteria, 9.8: 28equations, 2.6: 33–34flow, 9.8: 26free-surface vortices, 9.8: 26, 26f.at increased head, 1.6: 34, 2.6: 34instrumentation and measuring techniques, 9.8: 26liquid level, 9.8: 26model scope, 9.8: 25objectives, 9.8: 23pre-swirl, 9.8: 27procedure, 1.6: 32, 2.6: 32–34report preparation, 9.8: 28similitude and scale selection, 9.8: 24sub-surface vortices, 9.8: 26f., 27swirl in the suction pipe, 9.8: 27swirl meters, 9.8: 27, 27f.test plan, 9.8: 28velocity profiles, 9.8: 27

Modified radial flow impellers, 2.1-2.2: 3, 10f.Molded ring packings, 8.1-8.5: 17Monitoring

baseline, 9.6.5: 1failure mode indicators, 9.6.5: 1, 18–21frequency, 9.6.5: 1–2indicators, 9.6.5: 22–24

Monitoring devices, 4.1-4.6: 16, 20Monitoring equipment, 5.1-5.6: 15Motor dimensions

face-mounted, 1.1-1.2: 49t.HP and HPH vertical solid-shaft, 1.1-1.2: 53f., 53t.,

54t.type JM, 1.1-1.2: 51t.type JM having rolling contact bearings, 1.1-1.2: 50f.type JP, 1.1-1.2: 52t.type JP having rolling contact bearings, 1.1-1.2: 50f.

Motor efficiency, 3.6: 6, 19Motor insulation, 5.1-5.6: 13

temperature limits, 5.1-5.6: 26Motor power, 3.6: 19Motor winding integrity test, 5.1-5.6: 40Motor winding temperature test, 5.1-5.6: 40Mounting

base, 5.1-5.6: 21horizontal mounting base, 5.1-5.6: 21submerged, 5.1-5.6: 21vertical, 5.1-5.6: 21

Mounting, above and below floor discharge, 2.1-2.2: 2, 9f., 11f.

MSDS See Material Safety Data SheetsMud pump, 9.1-9.5: 4Multiple screw pump, 3.1-3.5: 11f.


16

Multiplex pump, 6.1-6.5: 2Multistage pumps, 9.6.1: 4Multi-volute casings, 1.3: 76

n See Speed, 11.6: 3Natural frequency, 9.6.4: 6, 7

and resonance, 9.6.4: 23Negative thrust, 4.1-4.6: 9Neodymium, 4.1-4.6: 8, 5.1-5.6: 14Net positive inlet pressure, 6.6: 5

See also Net positive suction head available, NPSHA test

Net positive inlet pressure available, 3.1-3.5: 17, 3.6: 5, 6.1-6.5: 25

Net positive inlet pressure required, 3.1-3.5: 17, 23, 3.6: 1, 5, 6.1-6.5: 25, 6.6: 5, 8.1-8.5: 9

See also Net positive suction head required, NPSHRacceptable deviation of quantities, 3.6: 15test, 3.6: 15and viscosity, 3.1-3.5: 23

Net positive suction head, 1.3: 38–4allowable, 9.6.3: 3available, 1.1-1.2: 58insufficient, 1.3: 43margin, 2.3: 21margin considerations, 1.3: 39NPSHA corrections for temperature and elevation,

1.3: 38reduction, 1.3: 39, 40f., 41f.reduction for liquids other than hydrocarbons or

water, 1.3: 40f., 41f., 42required, 1.1-1.2: 58requirements for pumps handling hydrocarbon

liquids and water at elevated temperatures, 1.3: 39, 40f., 41f., 2.3: 22, 23f., 24f.

Net positive suction head available, 1.6: 6, 2.1-2.2: 22, 2.3: 19, 7, 6.1-6.5: 25, 6.6: 5, 8.1-8.5: 10, 9.6.1: 1, 1f., 11.6: 5

calculation on a dry-pit pump, 11.6: 30calculation on a wet-pit pump, 11.6: 30correction to rated speed, 6.6: 10corrections for temperature and elevation, 2.3: 20

Net positive suction head marginSee NPSH margin

Net positive suction head required, 1.6: 1, 7, 2.1-2.2: 22, 2.6: 7, 6.1-6.5: 25, 6.6: 5, 8.1-8.5: 9, 9.6.1: 1, 1f., 11.6: 5

See also NPSHR testcorrection to rated speed, 6.6: 10

Net positive suction head required test, 2.6: 1, 18arrangements, 2.6: 18–20at constant rate of flow, 2.6: 21f., 20, 20f.correction to rated speed from test speed, 2.6: 21experimental deviation from the square law, 2.6: 21objective, 2.6: 18

procedure, 2.6: 20, 20f., 21f.records, 2.6: 22report, 2.6: 22test suction conditions, 2.6: 22at varying rate of flow, 2.6: 20, 21f.

Net positive suction head test. See Submersible pump NPSH test

Newtonian fluids, 3.1-3.5: 19Nickel alloys, 9.1-9.5: 21Nickel copper alloys, 9.1-9.5: 21Nickel or cobalt-chromium boron alloy, 9.1-9.5: 23Nickel-chromium-iron alloys, 9.1-9.5: 21Nickel-molybdenum alloys, 9.1-9.5: 21Nickel-molybdenum-chromium alloys, 9.1-9.5: 21NIST, 9.1-9.5: 50Noise, 1.4: 15, 2.4: 12, 9.6.3: 2

hydraulic resonance in piping, 2.4: 13Noise levels, 1.3: 57, 2.3: 18, 3.1-3.5: 27–29Nomenclature, 4.1-4.6: 5t.–6t., 8.1-8.5: 3, 9.8: 38

alphabetical listing, 1.1-1.2: 27t.–35t.numerical listing, 1.1-1.2: 35t.–38t.

Non-clog pumps, 1.3: 14Non-homogeneous flow, 6.1-6.5: 27, 9.1-9.5: 5Non-lubricating liquid, 4.1-4.6: 14Non-Newtonian fluids, 3.1-3.5: 22Nonreverse ratchets, 2.3: 46, 2.4: 8Non-settling slurry, 6.1-6.5: 27, 9.1-9.5: 5Normal condition point, 1.1-1.2: 58, 1.6: 1, 2.1-2.2: 22,

2.6: 1, 6.6: 1Nozzle loads

axial split case pumps, 9.6.2: 15end suction slurry pumps, 9.6.2: 16horizontal end suction pumps, 9.6.2: 1vertical turbine short set pumps, 9.6.2: 17vertical-in-line pumps, 9.6.2: 10

Nozzle stress, 3.1-3.5: 41Nozzles, 6.6: 14, 15t., 9.1-9.5: 4NPIPA See Net positive inlet pressure availableNPIPR See Net positive inlet pressure requiredNPSH margin, 9.6.1: 1, 10

building services pumping systems, 9.6.1: 9chemical process pumps, 9.6.1: 6cooling towers, 9.6.1: 7definedelectric power pumps, 9.6.1: 7general industrial pumps, 9.6.1: 9guidelines, 9.6.1: 4, 5t.nuclear power pumps, 9.6.1: 7petroleum process pumps, 9.6.1: 6pipeline pumps, 9.6.1: 10pulp and paper pumps, 9.6.1: 9ratio, 9.6.1: 1slurry service pumps, 9.6.1: 9and vertical turbine pumps, 9.6.1: 6water/wastewater pumps, 9.6.1: 8


17

waterflood (injection) pumps, 9.6.1: 10NPSH See Net positive suction headNPSHA margin, 9.6.3: 3, 3f.NPSHA See also Net positive suction head availableNPSHA See Net positive suction head allowableNPSHA. See Net positive suction head availableNPSHR See Net positive suction head requiredNPSHR See also Net positive suction head required

testNPSHR test, 1.6: 19

arrangements, 1.6: 19, 19f., 20f.closed tank supply, 6.6: 11, 12f.constant level supply, 6.6: 11correction to rated speed, 6.6: 12data presentation, 6.6: 12, 13f.equipment arrangements, 6.6: 11, 11f., 12f.level control with deep sump supply, 1.6: 20f., 20minimizing water aeration, 6.6: 12objective, 1.6: 19, 6.6: 11procedure, 1.6: 20, 6.6: 12with rate of flow held constant, 1.6: 21, 21f.records, 1.6: 22report, 1.6: 23suction conditions, 1.6: 22with suction head held constant, 1.6: 21, 21f.sump supply, 6.6: 11f., 11suppression type with constant level sump, 1.6: 19f.,

19test liquid, 6.6: 11tolerance parameters, 6.6: 12vacuum and/or heat control with closed loop,

1.6: 20f., 20NPSHR. See Net positive suction head requiredNST See Turbine specific speedNuclear power pumps, 9.6.1: 7

Octave-band analyzers, 9.1-9.5: 50Octave-band sound pressure levels, 9.1-9.5: 50, 51, 52Oersted, 4.1-4.6: 9Off design rating procedures, 4.1-4.6: 15Offset couplings, 1.3: 67Oil lubricated pumps, 2.3: 44Oil seal, 9.1-9.5: 4Open/enclosed impeller, 2.1-2.2: 2, 6f., 12f.Open/enclosed lineshaft, 2.1-2.2: 2, 6f.Open feedwater cycle, 1.3: 7, 7f., 2.3: 9, 10f.Open lineshafts, 2.3: 43Open suction tests, 2.6: 4, 4f., 6Operating principles, 4.1-4.6: 11Operating range, 2.3: 17, 17f.Operation, 4.1-4.6: 19–21, 5.1-5.6: 32

bearing lubrication, 1.4: 11bypass, 1.4: 13checking speed, rate of flow, pressure, power,

vibration and leaks, 2.4: 11

decoupling, 5.1-5.6: 35draw-down in wells, 2.4: 11filling, 1.4: 10flushing, 1.4: 10lubrication, 3.1-3.5: 44minimum flow, 1.4: 13parallel, 1.4: 14, 2.4: 12precautions, 5.1-5.6: 34pre-filling, 1.4: 11pre-startup, 3.1-3.5: 44prevention without liquid flow, 4.1-4.6: 19priming, 1.4: 10range, 5.1-5.6: 25reduced flow, 1.4: 13reverse runaway speed, 1.4: 14, 14f., 2.4: 12, 13f.series, 1.4: 14, 2.4: 12shutdown, 3.1-3.5: 45starting, 5.1-5.6: 34start-up, 1.4: 12, 2.4: 10, 3.1-3.5: 44stopping, 2.4: 12system preparation, 1.4: 10, 2.4: 9valve setting, 2.4: 10vibration, 5.1-5.6: 35water hammer, 1.4: 13, 2.4: 11

Operation and maintenance, 8.1-8.5: 14Orifice, 9.1-9.5: 4Outer magnet ring, 5.1-5.6: 14Outer magnetic assembly, 4.1-4.6: 9, 12Outlet, 3.1-3.5: 4, 33, 9.1-9.5: 4Outlet port, 9.1-9.5: 4Outlet pressure, 3.1-3.5: 16, 3.6: 4, 9Outside-adjustable lost-motion valve, 8.1-8.5: 6f.Overall efficiency, 1.1-1.2: 58, 1.6: 7, 2.1-2.2: 23f.,

2.6: 8, 3.6: 6, 6.6: 5, 11.6: 6calculation, 2.6: 16

Overhung impellerseparately coupled single stage–frame mounted,

1.1-1.2: 39f.Overhung impeller pumps, 1.1-1.2: 1f., 2, 1.3: 70

close couple single stage-diffuser style–end suction–submersible, 1.1-1.2: 5f.

close coupled single stage–end suction, 1.1-1.2: 4f.close coupled single stage–in-line, 1.1-1.2: 7f.close coupled single stage–submersible, 1.1-1.2: 6f.close coupled–single stage–end suction,

1.1-1.2: 47f.separately coupled single stage–axial flow–

horizontal, 1.1-1.2: 15f.separately coupled single stage–centerline

mounted, 1.1-1.2: 41f.separately coupled single stage–centerline mounted

(top suction), 1.1-1.2: 43f.separately coupled single stage–centerline mounted

pump on base plate (top suction), 1.1-1.2: 44f.


18

Overhung impeller pumps (continued)separately coupled single stage–centerline

mounted–pump on base plate, 1.1-1.2: 42f.separately coupled single stage–centerline support–

API 610, 1.1-1.2: 12f.separately coupled single stage–frame mounted,

1.1-1.2: 10f.separately coupled single stage–frame mounted–

ANSI B73.1, 1.1-1.2: 13f.separately coupled single stage–frame mounted–

lined pump, 1.1-1.2: 11f.separately coupled single stage–frame mounted–

mixed flow, 1.1-1.2: 21f.separately coupled single stage–frame mounted–

self-priming, 1.1-1.2: 24f.separately coupled single stage–in-line–flexible

coupling, 1.1-1.2: 8f.separately coupled single stage–in-line–rigid

coupling, 1.1-1.2: 9f.separately coupled single stage–wet pit volute,

1.1-1.2: 14f.separately coupled–single stage–frame mounted

(vertically mounted), 1.1-1.2: 47f.separately coupled–single stage–frame mounted–

pump on base plate, 1.1-1.2: 40f.

p See PressureP See PowerPmot See Submersible motor input powerPp See Pump input powerPw See Pump output powerpacc See Acceleration pressurepb See Barometric pressurePba See Bowl assembly input powerpd See Discharge pressurepd See Outlet pressurepd See Total discharge pressurepd See Working pressurepf See Friction loss pressurepg See Gauge pressurepH See Total differential pressurePmot See Electric driver input powerPmot See Electric motor input powerpmot See Total input powerPp See Pump input powerps See Inlet pressureps See Suction pressureps See Total suction pressurepv See Velocity pressurePw See Pump output powerPwba See Bowl assembly output powerpz See Elevation pressurePacemakers (precautions), 5.1-5.6: 32Pacemakers and magnets, 4.1-4.6: 19Packed stuffing-box, 1.3: 69, 69f., 70f.

Packing, 3.1-3.5: 5, 46, 9.1-9.5: 4allowance for expansion, 8.1-8.5: 16basis of recommendations, 8.1-8.5: 17canvas, 8.1-8.5: 17chemical, 8.1-8.5: 17clearance, 8.1-8.5: 18drip, 8.1-8.5: 17fitting, 8.1-8.5: 18, 18f.gland adjustment, 8.1-8.5: 16hydraulic packing, 8.1-8.5: 17installation, 8.1-8.5: 15lubrication, 8.1-8.5: 17molded ring, 8.1-8.5: 17soaking, 8.1-8.5: 18swelling, 8.1-8.5: 18

Packing box, 9.1-9.5: 4Packing gland, 9.1-9.5: 4Paper stock, 1.3: 15

See also Pulp and paper applicationsParallel misalignment, 3.1-3.5: 36, 37, 37f.Parallel operation, 1.4: 14, 2.4: 12Parallel operation and rate of flow, 2.3: 17, 17f.Parasitic losses, 5.1-5.6: 12Partially suspended solids, 9.1-9.5: 5Particles, 4.1-4.6: 14Parts, 2.1-2.2: 3, 6f.–12f.

alphabetical listing, 2.1-2.2: 14t.–18t.maintenance review, 4.1-4.6: 21names of, 4.1-4.6: 5t.–6t.

Parts replacements, 2.4: 14PATs See Pumps as turbinesPercent accumulation, 3.1-3.5: 5Percent overpressure, 3.1-3.5: 5Percent regulation, 3.1-3.5: 5Percent solids by volume, 6.1-6.5: 27, 9.1-9.5: 5Percent solids by weight, 6.1-6.5: 27, 9.1-9.5: 5Performance and selection criteria, 1.3: 21Performance test, 1.6: 9, 2.6: 1, 9, 6.6: 1

acceptable deviation of dependent test quantities from specified values, 3.6: 7

acceptable deviation of independent test quantities from specified values, 3.6: 6

acceptable instrument fluctuation, 6.6: 6acceptance, 3.6: 6, 6.6: 5acceptance criteria, 2.6: 9acceptance levels, 1.6: 9acceptance tolerances, 1.6: 9, 2.6: 9acceptance values, 6.6: 6accuracy, 3.6: 7bowl assembly, 2.6: 11, 11f.calculation of bowl assembly efficiency, 2.6: 16calculation of bowl assembly total head, 2.6: 15calculation of efficiency, 2.6: 15, 6.6: 9calculation of inlet or suction pressure, 6.6: 9calculation of input power, 6.6: 9


19

calculation of outlet or discharge pressure, 6.6: 9calculation of output power, 6.6: 9calculation of overall efficiency, 2.6: 16calculation of pump efficiency, 2.6: 16calculation of pump input power, 2.6: 15calculation of total differential pressure, 6.6: 9calculation of total discharge head, 2.6: 13calculation of total head, 2.6: 15calculations, 1.6: 15, 3.6: 11, 6.6: 9calculations of pump output power, 2.6: 15calculations of total suction head, 2.6: 13calibration interval for instruments, 1.6: 11, 12t.correcting for solids in suspension, 2.6: 18correcting for specific weight variations, 2.6: 18correcting for speed variations, 2.6: 17correcting for viscosity variations, 2.6: 18correction for solids in suspension, 1.6: 19correction for temperature variations, 1.6: 18correction for viscosity, 6.6: 10correction for viscosity variations, 1.6: 19correction to rated speed, 1.6: 17, 6.6: 10data requirements, 1.6: 13, 2.6: 13, 14f.data sheet, 6.6: 7, 8f.differential pressure formulas, 3.6: 11efficiency calculation, 1.6: 16efficiency formulas, 3.6: 11fluctuation, 3.6: 7fluctuation and accuracy, 2.6: 11t.at increased speed, 1.6: 17, 2.6: 17inlet conditions, 3.6: 8input power calculation, 1.6: 15input power formulas, 3.6: 11instrument calibration interval, 2.6: 9, 10t.instrument fluctuation and accuracy, 2.6: 10instrumentation, 1.6: 11, 2.6: 9, 3.6: 7, 20, 21t.,

6.6: 6instrumentation accuracy, 1.6: 11instrumentation fluctuation, 1.6: 11key conditions, 3.6: 8Level A acceptance, 3.6: 6level A acceptance, 1.6: 9Level B acceptance, 3.6: 6level B acceptance, 1.6: 9liquid conditions, 3.6: 9at non-rated conditions, 2.6: 16–18open or closed tank, 1.6: 13f.at other than rated speed, 1.6: 16outlet pressure, 3.6: 9output power calculation, 1.6: 15output power formulas, 3.6: 11plotting of results, 3.6: 12, 12f.plotting results, 1.6: 16, 16f., 2.6: 16, 16f., 6.6: 9,

10f.power correction (formula), 3.6: 11, 12f.procedure, 3.6: 9, 6.6: 7

pump (closed loop), 2.6: 11, 12f.pump (closed suction), 2.6: 11, 12f.pump (general), 2.6: 12rate of flow correction (formula), 3.6: 11records, 1.6: 15, 2.6: 13, 3.6: 10, 6.6: 9at reduced speed, 1.6: 16, 2.6: 16report, 1.6: 19, 2.6: 18, 6.6: 10sample data sheet, 1.6: 14setup, 1.6: 11, 2.6: 11–8f., 6.6: 6, 7f.for specific weight variations, 1.6: 18speed, 3.6: 9with suction lift, 1.6: 11f.tabulation sheet, 3.6: 10t.and temperature variations, 2.6: 17terminology, 6.6: 1–5total discharge head calculation, 1.6: 15total head calculation, 1.6: 15total suction head calculation, 1.6: 15Type I, 3.6: 10, 6.6: 6Type II, 3.6: 10, 6.6: 6Type III, 6.6: 6Type III and IV, 3.6: 7, 11Type III and IV reports, 3.6: 12, 14f.witnessing, 1.6: 9, 2.6: 9, 3.6: 6witnessing of, 6.6: 5

Performance. See also Submersible pump performance test

calculation based on change in pump impeller diameter, 11.6: 29

calculation based on change in pump speed, 11.6: 29

calculation of ranges based on level A and level B acceptance criteria tolerances, 11.6: 31

Peripheral velocity, 9.6.1: 2Permeability (magnetic), 4.1-4.6: 9Permeance, 4.1-4.6: 9Petroleum process pumps, 9.6.1: 6Phenolic piston rings, 8.1-8.5: 19

application, 8.1-8.5: 19clearance, 8.1-8.5: 20forms, 8.1-8.5: 20maximum concentration of chemicals, 8.1-8.5: 19t.

Pilot-operated relief valve, 9.1-9.5: 4Pipe dope, 8.1-8.5: 15Pipe tape, 8.1-8.5: 15Pipeline pumps, 9.6.1: 10Piping, 2.3: 45, 3.1-3.5: 38, 5.1-5.6: 33

See also Discharge piping, Suction pipinghydraulic resonance, 2.4: 13inlet, 3.1-3.5: 39jacket, 3.1-3.5: 39nozzle loads and criteria (limiting forces and

moments), 3.1-3.5: 39, 40t., 42t.outlet, 3.1-3.5: 39pipe-to-pump alignment, 3.1-3.5: 39f., 39


20

Piston cups, 8.1-8.5: 21f.assembling, 8.1-8.5: 21f.composition, 8.1-8.5: 20inspection, 8.1-8.5: 22installation, 8.1-8.5: 21list of liquids and materials suitable for, 8.1-8.5: 20nut tightening, 8.1-8.5: 21, 22f.synthetic rubber, 8.1-8.5: 21

Piston pumps, 3.1-3.5: 1f., 2, 2f., 6.1-6.5: 1, 6.1-6.5: 2f.

cup type pistons, 6.1-6.5: 64typical service, 6.1-6.5: 53–54

Piston rod load, 6.1-6.5: 23Piston rod packing

drip, 8.1-8.5: 17installation, 8.1-8.5: 15

Piston rod packing installation, 6.1-6.5: 60allowance for expansion of packing, 6.1-6.5: 61chemical packings, 6.1-6.5: 62drip, 6.1-6.5: 61gland adjustment, 6.1-6.5: 61hydraulic piston packing, 6.1-6.5: 62–63lubrication of packing, 6.1-6.5: 62metallic piston-ring-type packing, 6.1-6.5: 63–64molded ring packings, 6.1-6.5: 61phenolic piston ring packing, 6.1-6.5: 64, 64t.piston packing, 6.1-6.5: 62–64

Piston type, 8.1-8.5: 1f., 3Piston valves, 8.1-8.5: 4, 6f.Pit dimensional checks, 2.4: 3Pitot tubes, 6.6: 15Plastic fluids, 3.1-3.5: 22Plunger load, 6.1-6.5: 23Plunger or piston speed, 6.1-6.5: 20Plunger or piston velocity, 8.1-8.5: 7Plunger packing installation, 8.1-8.5: 15

See also Piston rod packing installationPlunger pumps, 6.1-6.5: 1f., 1, 2f., 3f.

typical service, 6.1-6.5: 53–54Plunger type, 8.1-8.5: 3Poise, 3.1-3.5: 19Poles (N-S), 4.1-4.6: 9, 5.1-5.6: 14Polymers

composites, 9.1-9.5: 16, 25elastomeric, 9.1-9.5: 24material selection for maximum continuous

temperature of various liquids, 9.1-9.5: 39, 40t.–44t., 45t.–49t.

rigid, 9.1-9.5: 16, 25thermosetting, 9.1-9.5: 25used in pump construction, 9.1-9.5: 38for various liquids, 9.1-9.5: 37, 38t.

Popping pressure, 3.1-3.5: 4POR See Preferred operating region

Positive displacement pumps, 9.1-9.5: 1, 2f.Positive thrust, 4.1-4.6: 9Power, 1.1-1.2: 58, 1.6: 7, 2.1-2.2: 23, 2.6: 7,

3.1-3.5: 18, 3.6: 5, 6.1-6.5: 23, 6.6: 5, 11.6: 5checking, 2.4: 11consumption too high, 2.4: 16correction to rated speed, 6.6: 10input to motors, 3.6: 19measurement, 1.6: 30, 2.6: 31–32measurements, 6.6: 17

Power check, 1.4: 13Power consumption, excessive, 5.1-5.6: 37Power drive end, 5.1-5.6: 12Power end

connecting rod, 6.1-6.5: 13, 14f.crankpin bearing, 6.1-6.5: 13, 14f.crankshaft, 6.1-6.5: 13, 13f.crosshead extension (plunger extension),

6.1-6.5: 14, 15f.frame extension, 6.1-6.5: 14, 15f.main bearing, 6.1-6.5: 13, 13f., 14f.parts, 6.1-6.5: 13–14, 15f.–18f., 19t.power crosshead, 6.1-6.5: 13, 14f.power frame, 6.1-6.5: 13, 13f.wrist pin, 6.1-6.5: 14, 15f.wrist pin bearing, 6.1-6.5: 14, 15f.

Power measurements, 3.6: 18–19Power monitoring, 9.6.5: 3

control limits, 9.6.5: 3frequency, 9.6.5: 3indicators, 9.6.5: 22means, 9.6.5: 3

Power plant pumps, 2.3: 9Power pump materials, 9.1-9.5: 18Precautions, 4.1-4.6: 11, 5.1-5.6: 34

hazardous materials, 5.1-5.6: 32with magnets, 5.1-5.6: 32starting, 5.1-5.6: 34

Preferred measurement units, 9.1-9.5: 7conversion factors, 9.1-9.5: 8t.–10t.rounded equivalents, 9.1-9.5: 7t.

Preferred operating region, 9.6.3: 1vertical pumps, 9.6.3: 1

Pre-installation, 2.4: 1foundation bolts, 1.4: 1, 2f.foundation requirements, 1.4: 1, 2.4: 2, 2f.handling equipment, 1.4: 1handling equipment for installation, 2.4: 1inspection, 2.4: 1installation tools, 1.4: 1location of unit, 1.4: 2long-term storage, 1.4: 1, 2.4: 1maintenance and repair access, 1.4: 1, 2.4: 2manufacturer’s erecting engineer, 1.4: 1


21

manufacturer’s instructions, 1.4: 1, 2.4: 1manufacturer’s service personnel, 2.4: 1protection against elements and environment, 1.4: 1receiving inspection, 1.4: 1short-term storage, 1.4: 1, 2.4: 1site preparation, 1.4: 1, 2.4: 1suction and discharge pipes, 1.4: 2tools for installation, 2.4: 1unloading, 2.4: 1

Pre-installation hydrotest, 9.6.5: 15axially split case pumps, 9.6.5: 16control limits, 9.6.5: 16double suction pumps, 9.6.5: 16frequency, 9.6.5: 16indicators, 9.6.5: 24means, 9.6.5: 15vertical double casing can type pumps, 9.6.5: 16warnings, 9.6.5: 15

Pre-lubricationcontrols and alarms, 2.4: 8drivers, 2.4: 8lube filtration types, 2.4: 8nonreverse ratchets, 2.4: 8pumps, 2.4: 8submersible pumps, 2.4: 9

Pressure, 3.1-3.5: 16, 3.6: 2, 6.1-6.5: 20–4, 8.1-8.5: 7calculation of inlet or suction pressure, 6.6: 9checking, 2.4: 11insufficient, 2.4: 16, 5.1-5.6: 36measurement, 3.6: 16–15measurement by gauges, 3.6: 18, 18f., 6.6: 16, 17f.,

17measurement by other methods, 6.6: 17multiple measurement orifices, 3.6: 17, 18f.tap location, 6.6: 15, 16t.tap openings, 3.6: 17, 17f., 6.6: 14, 14f.

Pressure boundary leakage failure mode causes and indicators, 9.6.5: 20t.

Pressure check, 1.4: 13Pressure monitoring, 9.6.5: 7

control limits, 9.6.5: 8frequency, 9.6.5: 8indicators, 9.6.5: 23means, 9.6.5: 8

Pressure pulsation, 3.1-3.5: 27Pressure rating, 5.1-5.6: 25Pressure tap opening, 2.6: 25f.Pre-startup, 3.1-3.5: 44Pre-swirl, 9.8: 1, 27Preventive maintenance, 3.1-3.5: 45Priming, 1.4: 10, 2.4: 9, 8.1-8.5: 14

by ejector or exhauster, 1.4: 10, 2.4: 9with foot valve, 1.4: 10by vacuum pumps, 1.4: 10, 2.4: 10

Priming time test, 1.6: 24conversion factor, 1.6: 25determination of maximum developed vacuum by

means of dry vacuum test, 1.6: 25of self-priming pumps, 1.6: 24suction line, 1.6: 24, 25f.

Probe locations, 9.6.4: 8between bearing, single and multistage, 9.6.4: 17f.end suction foot mounted, 9.6.4: 9f.end suction, centerline support, 9.6.4: 13f.end suction, close coupled horizontal and vertical in-

line, 9.6.4: 11f.end suction, frame mounted, 9.6.4: 12f.end suction, hard metal and rubber-lined horizontal

and vertical, 9.6.4: 16f.end suction, paper stock, 9.6.4: 14f.end suction, solids handling, horizontal and vertical,

9.6.4: 15f.vertical in-line, separately coupled, 9.6.4: 10f.vertical turbine, mixed flow and propeller type,

9.6.4: 18f.vertical turbine, short set pumps, assembled for

shipment by the manufacturer, 9.6.4: 19f.Process service, 1.3: 1, 2.3: 3Product lubricated bearings, 5.1-5.6: 13Propeller pumps See Axial flow pumpsProtection against seepage or flood, 8.1-8.5: 14Protective devices, 3.1-3.5: 43Proximity probes, 9.6.5: 9Pseudo-plastic fluids, 3.1-3.5: 22Pulp and paper applications, 1.3: 15, 9.6.1: 9

corrosion, 1.3: 16hydraulic performance correction, 1.3: 16paper stock and consistency categories, 1.3: 16

Pulsation dampener, 9.1-9.5: 4Pump displacement, 6.6: 3, 8.1-8.5: 7Pump duty cycle, 9.6.1: 4Pump efficiency, 1.1-1.2: 59, 1.6: 7, 2.1-2.2: 23, 2.6: 7,

3.1-3.5: 18, 3.6: 6, 11, 6.1-6.5: 23, 6.6: 5, 8.1-8.5: 10

calculation, 1.6: 16, 2.6: 16, 6.6: 9Pump hydraulic efficiency, 11.6: 6Pump input power, 1.1-1.2: 58, 1.6: 7, 2.1-2.2: 23,

2.6: 7, 3.1-3.5: 18, 3.6: 5, 11, 6.1-6.5: 23, 6.6: 5, 11.6: 5

calculation, 1.6: 15, 2.6: 15, 6.6: 9measurements, 1.6: 30, 2.6: 31, 3.6: 18, 6.6: 17and viscosity, 3.1-3.5: 23

Pump location, 8.1-8.5: 14Pump mechanical efficiency, 3.1-3.5: 18, 6.1-6.5: 23Pump output power, 1.1-1.2: 58, 1.6: 7, 2.1-2.2: 23,

2.6: 7, 3.1-3.5: 18, 3.6: 6, 11, 6.1-6.5: 23, 6.6: 5, 11.6: 6

calculation, 1.6: 15, 2.6: 15, 6.6: 9


22

Pump performance testsclosed loop, 2.6: 11, 12f.closed suction, 2.6: 11, 12f.general, 2.6: 12

Pump pressures, 1.1-1.2: 60, 2.1-2.2: 23–25Pump rate of flow, 8.1-8.5: 7Pump selection, 5.1-5.6: 25Pump selection criteria

axial thrust calculation, 2.3: 41f., 41, 42axial thrust terminology, 2.3: 40axial thrust vs. rate of flow, 2.3: 42, 43f.axial thrust with various impeller and shaft

configurations, 2.3: 38, 38f., 39f., 40f.continuous service, 2.3: 17cyclic service, 2.3: 17handling slurry liquids, 2.3: 36handling viscous liquids, 2.3: 22, 25f., 26f., 27f., 28f.impeller diameter change and pump performance,

2.3: 16, 16f.intermittent service, 2.3: 17liquids with vapor or gas, 2.3: 21, 21f.losses, 2.3: 33net positive suction head available, 2.3: 19noise levels, 2.3: 18non-settling slurries, 2.3: 36, 38f.NPSH margin, 2.3: 21NPSH requirements for pumps handling

hydrocarbon liquids and water at elevated temperatures, 2.3: 22, 23f., 24f.

operating range, 2.3: 17, 17f.operation away from best efficiency point, 2.3: 17parallel operation and rate of flow, 2.3: 17, 17f.pump versus system curves, 2.3: 13, 14f.pumping system requirements, 2.3: 13and reduced rates of flow, 2.3: 18reverse runaway speed, 2.3: 14rotating speed limitations, 2.3: 33, 34f., 35f.and runout conditions, 2.3: 18series operation and rate of flow, 2.3: 17, 17f.settling slurries, 2.3: 36, 38f.slurries and construction materials, 2.3: 36f.slurries and performance changes, 2.3: 36, 37f.slurries and rotative speed, 2.3: 38speed torque curves, 2.3: 15start-up and shut-down analysis, 2.3: 15submergence, 2.3: 19suction conditions, 2.3: 18suction specific speed, 2.3: 32system pressure limitation, 2.3: 14water hammer analysis, 2.3: 14

Pump shaft rotation, 2.1-2.2: 3Pump size, 9.6.1: 4Pump speeds, 8.1-8.5: 12Pump suction piping, 9.8: 20, 21f., 21t., 22f., 23f.

Pump torque, 3.1-3.5: 18, 6.1-6.5: 23characteristics, 6.1-6.5: 34requirements, 6.1-6.5: 35

Pump total discharge head, 2.1-2.2: 21Pump versus system curve, 1.3: 21, 21f., 2.3: 13, 14f.Pump vibration, 1.4: 17, 2.4: 12Pump volumetric efficiency, 3.1-3.5: 14, 3.6: 2Pumping chamber, 3.1-3.5: 4Pumping system requirements, 2.3: 13Pumping water level, 2.3: 5Pumps

characteristics, 4.1-4.6: 17constant speed pumping, 9.8: 58, 59t., 60t.decontamination of returned products, 9.1-9.5: 61defined, 9.1-9.5: 4hardware terms, 9.1-9.5: 3hydraulic phenomena adversely affecting, 9.8: 1kinetic, 9.1-9.5: 1, 2f.materials, 4.1-4.6: 15positive displacement, 9.1-9.5: 1, 2f.ratings, 4.1-4.6: 17slurry application terms, 9.1-9.5: 5sump volumes, 9.8: 54types of, 9.1-9.5: 1, 2f.variable speed, 9.8: 58

Pumps as turbines, 2.3: 11, 12f., 13f.Pumps operating in parallel, 1.3: 42, 42f.Pumps operating in series, 1.3: 42, 42f.Pumps used as hydraulic turbines, 1.3: 11

total available exhaust head (TAEH), 1.3: 12total required exhaust head (TREH), 1.3: 12turbine performance characteristics, 1.3: 11, 11f.,

12f.turbine specific speed, 1.3: 11

PWL See Pumping water level

Q See Flow rateQ See Rate of flowQ See also Pump rate of flow

Radial flow impellers, 2.1-2.2: 3Radial flow pumps, 1.1-1.2: 3, 3f.

separately coupled single stage–(vertical) split case, 1.1-1.2: 17f.

separately coupled–mulitstage–(vertical) split case, 1.1-1.2: 19f.

separately coupled–mulitstage–(vertical) split–double casing, 1.1-1.2: 20f.

Radial load, 5.1-5.6: 13Radial seal, 3.1-3.5: 5, 9.1-9.5: 4Radial thrust

calculation for volute pumps, 1.3: 58excessive, 1.3: 43


23

Rate of flow, 1.1-1.2: 55, 1.6: 3, 3.1-3.5: 14, 3.6: 2, 6.1-6.5: 20, 6.6: 4, 8.1-8.5: 7

checking, 2.4: 11correction formula, 3.6: 11correction to rated speed, 6.6: 10measurement, 3.6: 15, 6.6: 13measurement by displacement type meters, 6.6: 13measurement by head type rate meters, 1.6: 26,

6.6: 13, 14f.measurement by nozzles, 1.6: 27, 6.6: 14, 15t.measurement by other methods, 1.6: 29, 3.6: 16,

6.6: 15measurement by pitot tubes, 6.6: 15measurement by thin square-edged orifice plate,

1.6: 27, 6.6: 14measurement by venturi meter, 1.6: 26, 6.6: 14measurement by volume, 1.6: 25, 3.6: 16, 6.6: 13measurement by weight, 1.6: 25, 3.6: 16, 6.6: 13measuring system requirements, 1.6: 25and parallel operation, 2.3: 17, 17f.pressure tap openings, 1.6: 26, 26f.pressure tap openings for head type rate meter

measurements, 6.6: 14, 14f.reduced, 2.3: 18and series operation, 2.3: 17, 17f.straight pipe requirements associated with nozzle

meters, 1.6: 27, 28t.straight pipe requirements associated with orifice

plate meters, 1.6: 28t.straight pipe requirements associated with venturi

meters, 1.6: 26, 27t.types, 1.6: 25

Rate of flow (capacity), 2.1-2.2: 19defined, 2.6: 3measurement, 2.6: 24measurement by head type rate meters, 2.6: 24, 25f.measurement by nozzles, 2.6: 25, 26t., 27t.measurement by other methods, 2.6: 27measurement by pitot tubes, 2.6: 27measurement by thin, square-edged orifice plate,

2.6: 25, 26t., 27t.measurement by venturi meter, 2.6: 25, 26t.measurement by volume, 2.6: 24measurement by weight, 2.6: 24measurement by weirs, 2.6: 25

Rate of flow monitoring, 9.6.5: 11control limits, 9.6.5: 11frequency, 9.6.5: 11indicators, 9.6.5: 24measuring rate of flow, 9.6.5: 11

Rated (specified) condition point, 11.6: 3Rated condition point, 1.1-1.2: 58, 1.6: 1, 2.1-2.2: 22,

2.6: 1, 3.6: 2, 6.6: 1Receiver-pulsation dampener, 9.1-9.5: 4Receiving inspection, 1.4: 1

Reciprocating power pumps, 6.1-6.5: 1cup type pistons, 6.1-6.5: 64discharge piping, 6.1-6.5: 45foundation, 6.1-6.5: 55foundation bolts, 6.1-6.5: 56, 56f.inlet system, 6.1-6.5: 38–45inspection, 6.1-6.5: 65–66installation, 6.1-6.5: 56–60liquid end, 6.1-6.5: 5–8, 9f., 10f., 11f., 12t.location, 6.1-6.5: 55malfunctions, cause and remedies, 6.1-6.5: 66t.–

68t.power end, 6.1-6.5: 13–14, 15f.–18f., 19t.pre-installation considerations, 6.1-6.5: 55–56protection against seepage or flood, 6.1-6.5: 55right and left hand shaft extension, 6.1-6.5: 2–5servicing space, 6.1-6.5: 55speeds, 6.1-6.5: 29–34starting, 6.1-6.5: 34–38storage, 6.1-6.5: 55types and nomenclature, 6.1-6.5: 1typical services, 6.1-6.5: 29

Reciprocating power types, 6.1-6.5: 1f.Reciprocating pump materials, 9.1-9.5: 18Recirculation, 1.3: 43Recommended minimum spares, 1.1-1.2: 27Rectangular intakes

approach flow patterns, 9.8: 1design sequence, 9.8: 5t.dimensioning, 9.8: 2open vs. partitioned structures, 9.8: 2trash racks and screens, 9.8: 2

Rectangular wet wells, 9.8: 19Reducers, 2.4: 4, 4f., 5Reed frequency, 9.6.4: 6

See also Natural frequencyReference materials, 4.1-4.6: 23References, 5.1-5.6: 38Regenerative turbine pumps, 1.1-1.2: 1f., 1, 2, 1.4: 1

impeller between bearings–two stage, 1.1-1.2: 23f.peripheral single stage, 1.1-1.2: 22f.side channel single stage, 1.1-1.2: 22f.

Reinforced fibers, 9.1-9.5: 26Relief valve, 8.1-8.5: 15, 9.1-9.5: 4Relief valves, 3.1-3.5: 4, 43, 6.1-6.5: 45Reluctance, 4.1-4.6: 9Remedial measures, 9.8: 42

approach flow patterns, 9.8: 42, 43f., 44f., 45f.cross-flow, 9.8: 45, 46f.expansion of concentrated flows, 9.8: 46, 47f., 48f.,

49f.pump inlet disturbances, 9.8: 48, 49f., 51f.suction tank inlets, 9.8: 50, 52f.

Repair access, 2.4: 2Reseating pressure, 3.1-3.5: 5


24

Resonance, 9.6.4: 23in piping, 9.6.4: 24

Resonant frequency, 9.6.4: 6Return materials authorization number, 9.1-9.5: 61Reverse runaway speed, 1.3: 22, 1.4: 14, 14f., 2.3: 14,

2.4: 12, 13f.Revolution counter, 9.1-9.5: 4Revolution counter and timer method, 1.6: 31Revolution counter and timer method of speed

measurement, 6.6: 18Rheopectic fluids, 3.1-3.5: 22Right and left hand designations, 8.1-8.5: 3Rigid polymers and composites, 9.1-9.5: 25

parts, 9.1-9.5: 16Rigidity, 9.6.4: 24RMA See Return materials authorization numberRolling element bearings, 1.3: 64, 64t.Rotary pump materials, 9.1-9.5: 17Rotary pumps

data sheet for selection or design of, 3.1-3.5: 29, 30f.–32f.

noise levels, 3.1-3.5: 27–29specified conditions chart, 3.1-3.5: 24f.types, 3.1-3.5: 1, 1f.typical operating conditions, 3.1-3.5: 14

Rotary speed measurement, 3.6: 19Rotating assembly, 3.1-3.5: 4

multistage, axially split, single or double suction centrifugal pumps, 1.1-1.2: 26

single stage, axially (horizontally) split, single or double suction centrifugal pump, 1.1-1.2: 25

Rotating speed limitations, 2.3: 33, 34f., 35f.Rotation, 1.4: 13, 2.1-2.2: 3Rotation check, 3.1-3.5: 35Rotation of casing, 1.1-1.2: 26Rotation of pumps, 1.1-1.2: 26, 26f.Rotational inertia, 9.6.4: 4, 5Rotor, 3.1-3.5: 4, 9.1-9.5: 4Rotor balancing, 9.6.4: 20

allowable residual unbalance in pump impellers, 9.6.4: 21f., 22f.

maximum looseness between balancing arbor and impeller, 9.6.4: 23

Rotor lateral vibration, 9.6.4: 1See also Lateral critical speed

Rotor torsional vibration, 9.6.4: 1Rows of magnets, 5.1-5.6: 14RPM See Speed monitoringRunout conditions, 2.3: 18Rupture, 9.1-9.5: 3

s See Specific gravityS See SlipS See Suction specific speed

Safety, 6.1-6.5: 55, 8.1-8.5: 14characteristics, 4.1-4.6: 17mechanical, 4.1-4.6: 16secondary containment, 4.1-4.6: 16secondary control, 4.1-4.6: 16with magnets, 4.1-4.6: 19

Safety considerations, 5.1-5.6: 23, 9.6.5: 2Saltation, 6.1-6.5: 27, 9.1-9.5: 6Samarium cobalt, 4.1-4.6: 8, 5.1-5.6: 14Sanitary pump, 1.3: 14Screw pumps, 3.1-3.5: 1f., 3f., 3Seal cage, 3.1-3.5: 5Seal chamber, 3.1-3.5: 5, 13f., 9.1-9.5: 4Seal leakage failure mode causes and indicators,

9.6.5: 18t.Seal piping, 9.1-9.5: 4Sealants, 9.1-9.5: 26Sealing by impregnation, 9.1-9.5: 12Sealless (defined), 4.1-4.6: 11, 9.1-9.5: 4Sealless centrifugal pumps

advantages, 5.1-5.6: 23alternative designs, 5.1-5.6: 16application guidelines, 5.1-5.6: 23–26defined, 5.1-5.6: 12design, 5.1-5.6: 16–23items to be avoided, 5.1-5.6: 21limitations, 5.1-5.6: 23nomenclature, 5.1-5.6: 2, 10t.reference and source material, 5.1-5.6: 38safety considerations, 5.1-5.6: 23special considerations, 5.1-5.6: 16types, 5.1-5.6: 2f.uses, 5.1-5.6: 1

Sealless pumpsbearing wear monitoring (plain bearings), 9.6.5: 14failure mode causes and indicators, 9.6.5: 21t.temperature monitoring, 9.6.5: 4

Sealless rotary pumps, 4.1-4.6: 1overview, 4.1-4.6: 11

Second critical speed, 9.6.4: 1f., 1Secondary containment, 4.1-4.6: 9, 16, 5.1-5.6: 15

system, 4.1-4.6: 9Secondary control, 4.1-4.6: 9, 16

system, 4.1-4.6: 9Seismic analysis, 2.4: 14Self-priming pumps, 1.3: 13, 14f., 15f.Separately coupled (defined), 4.1-4.6: 9, 5.1-5.6: 12Separately coupled internal gear magnetic drive pump

with secondary control, 4.1-4.6: 1, 3f.Separately coupled screw type magnetic drive pump,

4.1-4.6: 1, 4f.Series operation, 1.4: 14, 2.4: 12Series operation and rate of flow, 2.3: 17, 17f.Servicing space, 8.1-8.5: 14


25

Set pressure, 3.1-3.5: 4Settling slurry, 6.1-6.5: 28, 9.1-9.5: 6Settling velocity, 6.1-6.5: 28, 9.1-9.5: 6Severity level, 9.6.5: 1–2Sewage pumps, 1.3: 14Shaft breakage mode causes and indicators,

9.6.5: 19t.Shaft deflection, 1.3: 70Shaft fatigue failure, 9.6.3: 3Shaft position monitoring, 9.6.5: 11

frequency, 9.6.5: 11indicators, 9.6.5: 24proximity probes, 9.6.5: 11

Shaft seal life, 9.6.3: 2Shaft seals

alternative, 1.3: 70mechanical seals, 1.3: 68, 69f.packed stuffing-box, 1.3: 69, 69f.

Shafting, 2.3: 43pump-to-driver, 2.3: 46

Shear pin relief valve, 9.1-9.5: 4Shear rate, 3.1-3.5: 19Shear stress, 3.1-3.5: 19Shipment inspection, 3.1-3.5: 33Shipping of magnets, 4.1-4.6: 19Short-term storage, 1.4: 1Shut off, 1.1-1.2: 58, 1.6: 1, 2.6: 1, 11.6: 3Shutdown, 1.3: 22, 3.1-3.5: 45Shut-down analysis, 2.3: 15Shutdown limit (defined), 9.6.5: 2Shutoff, 2.1-2.2: 22Silicon bronze, 9.1-9.5: 20Silicon carbide, 5.1-5.6: 13Simplex pump, 6.1-6.5: 2f., 2, 3f.Single plane balancing, 1.1-1.2: 60Single suction pump specific speed, 1.3: 32, 33f., 34f.Single volute casing, 1.3: 58, 58f., 76

K versus rate of flow, 1.3: 58, 59f.Single-acting pump, 6.1-6.5: 1f., 1, 2f.Site preparation, 2.4: 1

foundation bolts, 1.4: 1, 2f.foundation requirements, 1.4: 1location of unit, 1.4: 2maintenance access, 1.4: 1protection against elements and environment, 1.4: 1suction and discharge pipes, 1.4: 2

Sleeve bearings, 1.3: 64, 9.1-9.5: 4Slip, 3.1-3.5: 14, 3.6: 2, 5.1-5.6: 14, 6.1-6.5: 20, 6.6: 4,

8.1-8.5: 7hydraulic, 4.1-4.6: 10magnetic, 4.1-4.6: 9and slurries, 3.1-3.5: 26and viscosity, 3.1-3.5: 23

Sluice gates, 9.8: 60

Slurries, 2.3: 36, 3.1-3.5: 24apparent viscosity vs. shear rate, 3.1-3.5: 25, 26f.carrier liquids, 3.1-3.5: 24characteristics, 3.1-3.5: 24clearance provision for particle size, 3.1-3.5: 26concentration of solids in, 3.1-3.5: 25and construction materials, 2.3: 36construction materials for, 3.1-3.5: 27corrosion effect on wear, 3.1-3.5: 27flow velocity, 3.1-3.5: 26hardness of solids in, 3.1-3.5: 25, 25f.non-settling, 2.3: 36, 38f.operating sequences, 3.1-3.5: 27and performance changes, 2.3: 36, 37f., 3.1-3.5: 26,

26f.pressure relief provision, 3.1-3.5: 27pump design for, 3.1-3.5: 27and rotative speed, 2.3: 38sealing against, 3.1-3.5: 27settling, 2.3: 36, 38f.settling characteristics, 3.1-3.5: 25shear rate effect on friction power, 3.1-3.5: 26shear rate effect on slip, 3.1-3.5: 26size of solids in, 3.1-3.5: 25speed effect on wear, 3.1-3.5: 27speed effects, 3.1-3.5: 26testing and modeling for, 3.1-3.5: 27wear, 3.1-3.5: 27

Slurry, 6.1-6.5: 27, 9.1-9.5: 6Slurry application terms, 9.1-9.5: 5Slurry service, 1.3: 17–19

materials of construction for slurry pumps, 1.3: 17non-settling slurries, 1.3: 17, 19f.relationship between concentration and specific

gravity for aqueous slurries, 1.3: 17, 18f.rotational speed of slurry pumps, 1.3: 19settling slurries, 1.3: 17, 19f.

Slurry service pumps, 9.6.1: 9Slush pump, 9.1-9.5: 4Smothering gland, 9.1-9.5: 5SO See Shut offSoft start drivers, 6.1-6.5: 37Solids/abrasives in liquid, 9.6.1: 4Soluble chloride, 9.1-9.5: 11Sound level meters, 9.1-9.5: 50Source material, 5.1-5.6: 38Spacer type couplings, 3.1-3.5: 37Spare parts, 1.1-1.2: 27, 3.1-3.5: 46Specific composition bronze pumps, 9.1-9.5: 16, 17Specific gravity, 3.1-3.5: 23, 3.6: 6, 4.1-4.6: 14,

9.6.1: 2Specific heat, 4.1-4.6: 14Specific speed, 1.1-1.2: 2, 3f., 59, 2.1-2.2: 2Specific weight, 3.6: 6


26

Specifications, 4.1-4 .6: 17, 18f.Specified condition point, 1.1-1.2: 58, 1.6: 1,

2.1-2.2: 22, 2.6: 1, 3.6: 2Speed, 1.1-1.2: 55, 1.6: 3, 2.1-2.2: 19, 2.6: 3,

3.1-3.5: 14, 3.6: 2, 9, 6.1-6.5: 20, 8.1-8.5: 7, 11.6: 3

See also Reverse runaway speedchecking, 2.4: 11measurement, 1.6: 31, 2.6: 32and viscosity, 3.1-3.5: 23

Speed check, 1.4: 13Speed measurement, 6.6: 18Speed monitoring, 9.6.5: 13

constant speed systems, 9.6.5: 14control limits, 9.6.5: 14by electric counter, 9.6.5: 14frequency, 9.6.5: 14indicators, 9.6.5: 24methods, 9.6.5: 14by revolution counter, 9.6.5: 14by strobe light, 9.6.5: 14by tachometer, 9.6.5: 14variable speed systems, 9.6.5: 14

Speedsand application details, 6.1-6.5: 33basic speed ratings and formulas, 6.1-6.5: 29–33factors affecting operating speed, 6.1-6.5: 33high, 6.1-6.5: 34and liquid characteristics, 6.1-6.5: 33medium, 6.1-6.5: 33and pump design, 6.1-6.5: 33slow, 6.1-6.5: 34and type of duty, 6.1-6.5: 33

Speed-torque curves, 1.4: 13, 2.3: 15, 2.4: 10Square root law, 9.1-9.5: 6Stainless steel fitted pumps, 9.1-9.5: 16Standards-setting organizations, 11.6: 32Start, 1.4: 12Starting, 5.1-5.6: 34, 6.1-6.5: 34

with liquid bypass, 6.1-6.5: 35, 36f.without liquid bypass, 6.1-6.5: 35pump torque characteristics, 6.1-6.5: 34pump torque requirements, 6.1-6.5: 35soft start drivers, 6.1-6.5: 37torque, 5.1-5.6: 13

Start-to-discharge pressure, 3.1-3.5: 4Start-up, 2.4: 10, 3.1-3.5: 44

across-the-line, 2.4: 10caution, 2.4: 10discharge valve position, 1.4: 12dowelling, 1.4: 13final alignment check, 1.4: 13flow rate check, 1.4: 13leak check, 1.4: 13misalignment causes, 1.4: 13

motor, 1.4: 13power check, 1.4: 13pressure check, 1.4: 13reduced voltage, 2.4: 10rotation, 1.4: 13speed check, 1.4: 13speed-torque curves, 1.4: 13, 2.4: 10valve setting, 2.4: 11vibration check, 1.4: 13with closed discharge valve, 1.3: 22with open discharge valve, 1.3: 22

Start-up analysis, 2.3: 15Static balancing, 1.1-1.2: 60Static suction lift, 1.1-1.2: 58, 2.1-2.2: 22, 6.1-6.5: 25,

8.1-8.5: 10Static water level, 2.3: 5Stator, 3.1-3.5: 4Steam electric power plants, 1.3: 4, 5f., 2.3: 6

boiler circulating pumps, 1.3: 10boiler feed booster pumps, 1.3: 9boiler feed pumps, 1.3: 8closed feedwater cycle, 1.3: 6, 7f.condensate pumps, 1.3: 9condenser circulating pumps, 1.3: 9heater drain pumps, 1.3: 10open feedwater cycle, 1.3: 7, 7f.pumps, 1.3: 8steam power cycle, 1.3: 4, 5f.

Steam jacket, 9.1-9.5: 5Steam power cycle, 1.3: 4, 5f., 2.3: 7f., 7Steam power plants, 2.3: 6, 8f.

closed feedwater cycle, 2.3: 9f., 9condensate pumps, 2.3: 9condenser circulating water pumps, 2.3: 10heater drain pumps, 2.3: 11open feedwater cycle, 2.3: 9, 10f.power plant pumps, 2.3: 9steam electric power plants, 2.3: 6steam power cycle, 2.3: 7f., 7

Steam turbine drivers, 1.3: 77Steel

all stainless steel pumps, 9.1-9.5: 16, 17carbon and low alloy steels, 9.1-9.5: 19chromium (ferric) stainless steel, 9.1-9.5: 20chromium-nickel (austenitic) stainless steel,

9.1-9.5: 19duplex stainless steels, 9.1-9.5: 20high alloy steels, 9.1-9.5: 19stainless steel fitted pumps, 9.1-9.5: 16

Stoke, 3.1-3.5: 19Stop valve, 9.1-9.5: 5Stopping, 2.4: 12Storage, 1.4: 1, 3.1-3.5: 33, 8.1-8.5: 14Storage (pre-installation), 2.4: 1


27

Strain gauge type torque measuring devices, 1.6: 30, 31

Strainers, 3.1-3.5: 42, 5.1-5.6: 13Stripping applications, 4.1-4.6: 15Stroboscopes, 1.6: 31, 6.6: 18Stroke, 6.1-6.5: 20, 6.6: 3, 8.1-8.5: 7Structure dynamic analysis, 9.6.4: 7Structure lateral vibration, 9.6.4: 1, 6

vertical dry pit pumps, 9.6.4: 6vertical wet pit pumps, 9.6.4: 6

Structureborne noise, 3.1-3.5: 28Stuffing box, 3.1-3.5: 5, 13f., 9.1-9.5: 5

area, 1.1-1.2: 48f.bushings, 1.4: 6, 9.1-9.5: 5mechanical seals, 1.4: 6, 2.4: 7packing, 1.4: 5, 2.4: 7, 7f.

Submerged mounting, 5.1-5.6: 21Submerged suction, 1.1-1.2: 58, 2.1-2.2: 22,

6.1-6.5: 24, 8.1-8.5: 10Submerged vortices, 9.8: 1Submergence, 1.1-1.2: 57, 2.3: 19Submergence required for minimizing surface vortices,

9.8: 29, 33f., 34f.Submersible motor efficiency, 11.6: 6Submersible motor input power, 11.6: 6Submersible motor integrity tests

electrical continuity and resistance test, 11.6: 16electrical high-potential test, 11.6: 17electrical megohmmeter resistance test, 11.6: 17housing pressure test, 11.6: 16, 16f.housing vacuum check, 11.6: 16, 17f.objective, 11.6: 15records, 11.6: 17setup and procedure, 11.6: 15

Submersible pump hydrostatic testacceptance criteria, 11.6: 12objective, 11.6: 10procedure, 11.6: 11records, 11.6: 12setup, 11.6: 11, 11f.

Submersible pump NPSH test, 11.6: 12acceptance criteria, 11.6: 15closed-loop dry pit setup, 11.6: 13f., 13closed-loop wet pit setup, 11.6: 13, 14f.with flow rate held constant, 11.6: 14objective, 11.6: 12procedure, 11.6: 14records, 11.6: 15setup, 11.6: 12, 12f., 13f., 14f.with suction head held constant, 11.6: 14, 15f.suction throttling setup, 11.6: 12f., 12variable lift setup, 11.6: 13f., 13

Submersible pump performance testacceptance criteria, 11.6: 9dry pit setup, 11.6: 7, 8f.

efficiency tolerance at specified flow rate, 11.6: 9, 10t.

flow rate tolerance at specified total head, 11.6: 9, 10t.

objective, 11.6: 7pretest data requirements, 11.6: 10procedure, 11.6: 8records, 11.6: 10setup, 11.6: 7, 7f., 8f.test curve, 11.6: 10, 11f.total head tolerance at specified flow rate, 11.6: 9t., 9wet pit setup, 11.6: 7, 7f.

Submersible pump tests, 11.6: 1flow-measuring systems, 11.6: 19gauges in head measurement, 11.6: 24, 26f.instrument calibration intervals, 11.6: 18,: 21t.instrument fluctuation and inaccuracy, 11.6: 18, 21t.model tests, 11.6: 27noncontact type flow meters in rate of flow

measurement, 11.6: 24pressure differential meters in rate of flow

measurement, 11.6: 22, 22t., 23t.pressure tap location for head measurement,

11.6: 24, 25f.pump input power measurement, 11.6: 25rotary speed measurement, 11.6: 26rotating type flow meters in rate of flow

measurement, 11.6: 22routine production tests, 11.6: 1standards-setting organizations, 11.6: 32subscripts, 11.6: 3t.symbols, 11.6: 2t.temperature measurement, 11.6: 27terminology and definitions, 11.6: 1test conditions, 11.6: 1test types, 11.6: 1weirs in rate of flow measurement, 11.6: 22witnessing of tests, 11.6: 1

Submersible pump vibration testacceptance criteria, 11.6: 18objective, 11.6: 18procedure, 11.6: 18pump support, 11.6: 18records, 11.6: 18setup, 11.6: 18vibration instrumentation (transducer), 11.6: 18, 19f.vibration limits, 11.6: 18, 20f.

Submersible pumps, 1.1-1.2: 5f., 6f., 2.1-2.2: 2, 7f.special considerations, 2.4: 9

Submersible vertical turbine pump intakes, 9.8: 11, 14Subscripts, 1.1-1.2: 57t., 1.3: 3t., 1.6: 3t., 2.1-2.2: 19,

21t., 2.3: 3t., 2.6: 3t., 3.1-3.5: 16t., 3.6: 4t., 6.1-6.5: 22t., 6.6: 1, 3t., 8.1-8.5: 9t.

Sub-surface vortices, 9.8: 26f., 27


28

Suction, 3.1-3.5: 33loss of, 2.4: 16, 5.1-5.6: 37pressure, 5.1-5.6: 15

Suction and discharge pipes, 1.4: 2expansion joints and couplings, 1.4: 7flat faced flanges, 1.4: 7pipe support and anchors, 1.4: 7requirements, 1.4: 7, 8

Suction conditions, 1.1-1.2: 58, 1.3: 57, 2.1-2.2: 22, 2.3: 18, 6.1-6.5: 24, 8.1-8.5: 10

Suction energy, 9.6.1: 10, 5determination, 9.6.1: 3, 3f.factors, 9.6.1: 2

Suction energy level, 9.6.1: 1Suction nozzle, 9.1-9.5: 5Suction piping, 2.4: 4

See also Discharge piping, Pipingeccentric reducers, 2.4: 4, 4f.elbows, 2.4: 5reducers, 2.4: 4, 4f., 5requirements, 2.4: 4strainers, 2.4: 5supports, anchors, and joints, 2.4: 4tanks, 2.4: 5valves, 2.4: 5

Suction port, 3.1-3.5: 4, 9.1-9.5: 3Suction pressure, 1.1-1.2: 60, 8.1-8.5: 7Suction pumps, 1.1-1.2: 4f.

datum elevations, 1.1-1.2: 55f.submersible, 1.1-1.2: 5f.

Suction recirculation, 1.3: 43, 9.6.3: 5centrifugal pumps, 9.6.3: 5, 5f., 6f., 7f.large boiler feed pumps, 9.6.3: 8vertical turbine pumps, 9.6.3: 8, 8t.

Suction specific speed, 1.1-1.2: 3f., 3, 1.3: 32, 33f., 34f., 35f., 36f., 2.3: 32, 9.6.1: 1, 9.6.3: 5

Suction system relationships, 6.1-6.5: 41, 42f., 43f.Suction tanks, 9.8: 9

minimum submergence, 9.8: 10, 10f., 11f.multiple inlets or outlets, 9.8: 11NPSH considerations, 9.8: 11simultaneous inflow and outflow, 9.8: 11

Sump volumecalculating, 9.8: 54decreasing by pump alternation, 9.8: 57minimum sequence, 9.8: 55operational sequences, 9.8: 55, 56f.pump and system head curves, 9.8: 55, 56f.

Surface vorticesrequired submergence for minimizing, 9.8: 29, 33f.,

34f.Swirl, 9.8: 1

in the suction pipe, 9.8: 27meters, 9.8: 27, 27f.

SWL See Static water level

Symbols, 1.1-1.2: 56t., 1.3: 1, 2t., 1.6: 2t., 2.1-2.2: 19, 20t., 2.3: 1, 2t., 3t., 2.6: 2t., 3.1-3.5: 15t., 3.6: 3t., 6.1-6.5: 21t., 6.6: 1, 2t., 8.1-8.5: 8t., 9.8: 38

Synchronous drive, 4.1-4.6: 10Synchronous magnet coupling, 4.1-4.6: 11System piping, 2.3: 45System preparation, 2.4: 9

filling, 1.4: 10flushing, 1.4: 10pre-filling, 1.4: 11priming, 1.4: 10

System pressure limitation, 1.3: 22, 2.3: 14System ratings, 4.1-4.6: 17System requirements, 1.3: 21

double suction pump specific speed, 1.3: 32, 35f., 36f.

effects of handling viscous liquids, 1.3: 23, 24f., 25f., 26f., 27f.

net positive suction head, 1.3: 38–42NPSH margin considerations, 1.3: 39NPSH reduction, 1.3: 39, 40f., 41f.NPSH reduction for liquids other than hydrocarbons

or water, 1.3: 40f., 41f., 42NPSH requirements for pumps handling

hydrocarbon liquids and water at elevated temperatures, 1.3: 39, 40f., 41f.

NPSHA corrections for temperature and elevation, 1.3: 38

pump selection for a given head, rate of flow, and viscosity, 1.3: 28

pump versus system curve, 1.3: 21, 21f.reverse runaway speed, 1.3: 22shut-down, 1.3: 22single suction pump specific speed, 1.3: 32, 33f.,

34f.starting with closed discharge valve, 1.3: 22starting with open discharge valve, 1.3: 22start-up, 1.3: 22suction specific speed, 1.3: 32, 33f., 34f., 35f., 36f.system pressure limitation, 1.3: 22torque curves, 1.3: 23, 23f.viscous liquid calculations, 1.3: 30t., 31, 32t.viscous liquid performance correction chart

limitations, 1.3: 23viscous liquid performance curves, 1.3: 30f., 30, 31f.viscous liquid performance when water performance

is known, 1.3: 29, 30f., 31f.viscous liquid symbols and definitions, 1.3: 28water hammer, 1.3: 22

t See TemperatureTachometers, 1.6: 31, 6.6: 18, 9.1-9.5: 5TAEH See Total available exhaust headTail rod, 6.6: 3


29

Tape recorders, 9.1-9.5: 50Temperature, 3.1-3.5: 18, 4.1-4.6: 13

bearing, 1.3: 75correction, 3.6: 13Curie, 4.1-4.6: 7, 5.1-5.6: 14effects on NPSH and drive section, 5.1-5.6: 25high, 5.1-5.6: 24in hydrostatic test, 6.6: 10instruments, 1.6: 32internal rise, 4.1-4.6: 20limits, 1.4: 12, 5.1-5.6: 13limits of magnets, 4.1-4.6: 20limits on end suction pumps, 1.3: 78, 78t.measurement, 1.4: 11, 1.6: 32, 3.6: 20, 6.6: 18rise in drive section, 5.1-5.6: 13vs. time, 1.4: 12, 12f.

Temperature buildup, 1.3: 43Temperature measurement and instruments, 2.6: 32Temperature monitoring, 9.6.5: 3

control limits, 9.6.5: 5frequency, 9.6.5: 5indicators, 9.6.5: 23liquid film bearing and seal faces temperatures,

9.6.5: 4means, 9.6.5: 4motor winding temperature, 9.6.5: 4pumped liquid temperature rise, 9.6.5: 4rolling element bearing temperatures, 9.6.5: 4sealless pump liquid temperature, 9.6.5: 4sealless pump temperature damage, 9.6.5: 5temperature sensitive fluids, 9.6.5: 4

Temperature rise, 1.3: 43, 9.6.3: 2calculation, 1.3: 43, 44f., 45f.and minimum flow, 1.3: 46and pump performance, 1.3: 44, 44f.

Terminology, 1.3: 1, 2t., 1.6: 1, 2.6: 1–8, 3.1-3.5: 15t., 3.6: 2–6, 4.1-4.6: 7–35

alphabetical listing, 1.1-1.2: 27t.–35t.numerical listing, 1.1-1.2: 35t.–38t.

Tests, 1.6: 1, 4.1-4.6: 24, 5.1-5.6: 39conditions, 1.6: 1explanation, 3.6: 1hermetic integrity, 5.1-5.6: 39hermetic integrity test, 4.1-4.6: 24inert gas sniffer test, 4.1-4.6: 24mechanical integrity, 5.1-5.6: 40objectives, 1.6: 1reports, 5.1-5.6: 40scope, 1.6: 1torque confirmation test, 4.1-4.6: 24types, 3.6: 1winding integrity, 5.1-5.6: 40winding temperature, 5.1-5.6: 40

Thermal effects on NPSH and drive section, 5.1-5.6: 25

Thermodynamic properties, 9.6.1: 2Thermoplastics, 9.1-9.5: 25Thermosetting polymers, 9.1-9.5: 25Thin square-edged orifice plate, 6.6: 14Thixotropic fluids, 3.1-3.5: 22Thrust bearings, 2.3: 46Thrust reversal on impeller, 9.6.3: 3Tie-down fasteners, 3.1-3.5: 40Time-independent non-Newtonian fluids, 3.1-3.5: 22Timing gear, 3.1-3.5: 4, 9.1-9.5: 5Tin bronze, 9.1-9.5: 20Tin-base bearing metals, 9.1-9.5: 23Titanium alloys, 9.1-9.5: 23Top suction impellers, 1.3: 20, 21f.Torque, 5.1-5.6: 12Torque confirmation test, 4.1-4.6: 24Torque curves, 1.3: 23, 23f.Torque shafts, 3.6: 18Torsional critical speed, 9.6.4: 4, 4f.

calculation, 9.6.4: 5Torsional dynamic analysis, 9.6.4: 5Torsional dynamometer, 9.1-9.5: 5Torsional stiffness, 9.6.4: 4, 5Total available exhaust head, 1.3: 12, 2.3: 13Total differential pressure, 6.1-6.5: 22, 6.6: 4,

8.1-8.5: 7calculation, 6.6: 9

Total discharge head, 1.1-1.2: 57, 1.6: 5, 2.1-2.2: 21, 2.6: 5, 5f., 11.6: 5

calculations, 1.6: 15, 2.6: 13Total discharge pressure, 6.1-6.5: 20, 6.6: 4

calculation, 6.6: 9Total gap, 4.1-4.6: 8, 5.1-5.6: 12Total head, 1.1-1.2: 57, 59, 1.6: 5, 2.1-2.2: 21, 2.6: 5,

6, 11.6: 5calculation, 1.6: 15, 2.6: 15effects of compressibility of liquid on, 1.6: 5measurement, closed suction above atmospheric

pressure (can pump), 2.6: 29, 29f.measurement, open suction above atmospheric

pressure (wet pit), 2.6: 30, 30f.Total head tolerance at specified flow rate, 11.6: 9t., 9Total input power, 3.6: 5, 6.6: 5Total required exhaust head, 1.3: 12, 2.3: 13Total suction head, 1.6: 4, 2.6: 4, 5, 5f., 11.6: 4

calculation, 1.6: 15calculations, 2.6: 13closed suction, 2.1-2.2: 19closed suction test, 1.1-1.2: 57net positive suction head available, 1.1-1.2: 58net positive suction head required, 1.1-1.2: 58open suction, 1.1-1.2: 57, 2.1-2.2: 19

Total suction lift, 1.6: 5, 6.1-6.5: 25, 6.6: 4, 8.1-8.5: 10Total suction pressure, 6.1-6.5: 20, 6.6: 4

calculation, 6.6: 9


30

Toxic liquids or vapors, 8.1-8.5: 14Toxicity ratings, 5.1-5.6: 23Transfer pumping, 1.3: 4Transfer service, 2.3: 4Transition manholes, 9.8: 59Transmission dynamometers, 1.6: 30, 31, 9.1-9.5: 5Trash pumps, 1.3: 14TREH See Total required exhaust headTrench-type intakes, 9.8: 7, 8f., 9f.

approach velocity, 9.8: 9centerline spacing, 9.8: 9end wall clearance, 9.8: 9floor clearance, 9.8: 9inlet conduit elevation, 9.8: 9orientation, 9.8: 9width, 9.8: 9

Trench-type wet wells, 9.8: 16f., 17Troubleshooting, 2.4: 15, 5.1-5.6: 36

See Malfunctions, causes and remediesexcessive power consumption, 1.4: 16, 5.1-5.6: 37insufficient discharge, 2.4: 15insufficient discharge flow, 5.1-5.6: 36insufficient discharge flow or pressure, 1.4: 16insufficient pressure, 2.4: 16, 5.1-5.6: 36little or no discharge flow, 1.4: 16loss of suction, 1.4: 16, 2.4: 16, 5.1-5.6: 37no discharge, 2.4: 15no discharge flow, 5.1-5.6: 36power consumption too high, 2.4: 16

Turbine specific speed, 1.3: 11, 2.3: 12Turbines See Pumps as turbinesTwo plane balancing, 1.1-1.2: 61Type I performance test, 6.6: 6Type II performance test, 6.6: 6Type III performance test, 6.6: 6Type JM motors, 1.1-1.2: 51t.

having rolling contact bearings, 1.1-1.2: 50f.Type JP motors, 1.1-1.2: 52t.

having rolling contact bearings, 1.1-1.2: 50f.

Unbalance, 9.6.4: 20allowable residual in impellers, 9.6.4: 21f., 22f.maximum looseness between balancing arbor and

impeller, 9.6.4: 23Unconfined intakes, 9.8: 14

cross-flow velocities and pump location, 9.8: 15debris and screens, 9.8: 15submergence, 9.8: 15

Units (pumps complete with mounting bases), 3.1-3.5: 33

Units of measure, 1.3: 1, 2t., 2.3: 1, 2t., 3t., 3.1-3.5: 15t., 9.1-9.5: 7

conversion factors, 9.1-9.5: 8t.–10t.rounded equivalents, 9.1-9.5: 7t.viscosity, 3.1-3.5: 19

Universal joint, 9.1-9.5: 5Unloading, 2.4: 1US Customary units, 9.1-9.5: 7

conversion factors, 9.1-9.5: 8t.–10t.rounded equivalents, 9.1-9.5: 7t.

v See Plunger or piston speedv See VelocityVacuum breaker piping, 9.1-9.5: 5Valve gear, 8.1-8.5: 4Valve gear adjustments, 8.1-8.5: 4, 6f.Valve plate type, 8.1-8.5: 3, 3f.Valve pot type, 8.1-8.5: 3, 4f.Valve seat area, 6.1-6.5: 24, 24f., 25f.Valve setting, 2.4: 10

discharge valve position (high or medium head pumps), 2.4: 11

discharge valve position (mixed or axial flow pumps), 2.4: 11

reduced flow/minimum flow discharge bypass, 2.4: 11

at start-up, 2.4: 11warning against closed valve operation, 2.4: 10

Vane pumps, 3.1-3.5: 1f., 1Vane-in-rotor pumps, 3.1-3.5: 1f., 2, 2f.Vane-in-stator pumps, 3.1-3.5: 1f., 2, 2f.Vapor, 2.3: 21Vapor See Liquids with vapor or gasVapor pressure, 3.1-3.5: 23Variable speed drives, 1.3: 77, 2.3: 45Variable speed pumps, 9.8: 58Variable viscosity, 4.1-4.6: 14Vegetable oils, 9.1-9.5: 11Velocity, 8.1-8.5: 7, 9.8: 1Velocity head, 1.1-1.2: 55, 1.6: 4, 2.1-2.2: 19, 2.6: 4,

11.6: 4Velocity pressure, 3.1-3.5: 16, 3.6: 4, 6.1-6.5: 22,

6.6: 4, 8.1-8.5: 9Velocity profiles, 9.8: 27Vent piping, 9.1-9.5: 5Venting, 5.1-5.6: 18Venturi meter, 6.6: 14, 9.1-9.5: 5Vertical diffuser pumps (excluded), 1.4: 1Vertical hollow shaft drivers, 2.4: 6Vertical mounting, 5.1-5.6: 21Vertical pump materials, 9.1-9.5: 16Vertical pump tests, 2.6: 1

conditions, 2.6: 1Vertical pumps, 2.4: 1, 6.1-6.5: 1, 2f.

bearing and spacing types, 2.3: 42classification by configuration, 2.1-2.2: 2classification by impeller design, 2.1-2.2: 2definition, 2.1-2.2: 1drivers, 2.3: 45enclosed lineshaft, 2.3: 43


31

final alignment check, 2.4: 8flexibility of design, 2.3: 1foundation, 2.3: 45impeller types, 2.3: 44intake system design, 2.3: 46leveling and plumbness, 2.4: 3, 3f.locating, 2.4: 3lubrication systems, 2.3: 43open lineshaft, 2.3: 43operating, 2.4: 9pre-lubrication, 2.4: 8shafting, 2.3: 43system piping, 2.3: 45types, 2.1-2.2: 1, 4f.typical applications, 2.3: 1–13vibration, 2.4: 12

Vertical solid shaft drivers, 2.4: 6Vertical solid-shaft motor dimensions (HP and HPH),

1.1-1.2: 53f., 53t., 54t.Vertical turbine pumps, 9.6.1: 6

and inlet eye diameter, 9.6.1: 4and NPSH margin, 9.6.1: 6

Vertical turbine short set pumps, 9.6.2: 17force analysis, 9.6.2: 17loading examples, 9.6.2: 32nozzle loads, 9.6.2: 17, 18f., 19f.terminology, 9.6.2: 17

Vertical volute pump installationalignment, 1.4: 9configurations, 1.4: 8couplings, 1.4: 9, 10discharge piping requirements, 1.4: 8flexible or line shaft configuration, 1.4: 8grouting, 1.4: 8in-line configuration, 1.4: 8mounting to support structure, 1.4: 9pump leveling and plumbness, 1.4: 8separately coupled configuration, 1.4: 8solid shaft coupling, 1.4: 10stuffing-box steps, 1.4: 10suction piping requirements, 1.4: 8v-belt drive, 1.4: 10wet pit configuration, 1.4: 8

Vertical-in-line pumpsadjustment factors, 9.6.2: 11, 14t.flange stress, 9.6.2: 10material specifications, 9.6.2: 13t.nomenclature, 9.6.2: 10, 10f.nozzle loads, 9.6.2: 10, 12t.pressure-temperature, 9.6.2: 10

Vibration, 1.4: 17, 2.4: 12, 5.1-5.6: 35, 9.6.3: 2checking, 2.4: 11dynamics, 9.6.4: 1factors affecting, 9.6.4: 20field values, 9.6.4: 8, 9f.–19f.

frequencies and methods of determination, 9.6.4: 1measurements, 9.6.4: 7probe locations, 9.6.4: 8, 9f.–19f.

Vibration check, 1.4: 13Vibration monitoring, 9.6.5: 8

bearing housing vibrations, 9.6.5: 8control limits, 9.6.5: 9frequency, 9.6.5: 9indicators, 9.6.5: 22means, 9.6.5: 8proximity probe, 9.6.5: 9shaft vibrations, 9.6.5: 8on vertical pumps, 9.6.5: 9

Vibration test. See Submersible pump vibration testViscometers, 3.1-3.5: 19Viscosity, 3.1-3.5: 19, 4.1-4.6: 13, 5.1-5.6: 25

apparent, 3.1-3.5: 19dynamic, 3.1-3.5: 19effect on pump and system performance, 3.1-3.5: 23high, 3.1-3.5: 14, 4.1-4.6: 13kinematic, 3.1-3.5: 19low, 3.1-3.5: 14, 4.1-4.6: 13units of measure, 3.1-3.5: 19variable, 4.1-4.6: 14

Viscous input power, 1.3: 30Viscous liquids

calculations, 1.3: 30t., 31, 32t.correction chart limitations, 2.3: 22effects of handling, 1.3: 23, 24f., 25f., 26f., 27f.handling, 2.3: 22, 25f., 26f., 27f., 28f.performance correction chart limitations, 1.3: 23performance correction charts, 2.3: 25f., 26f., 27f.,

28f.performance curves, 1.3: 30f., 30, 31f.performance when water performance is known,

1.3: 29, 30f., 31f.pump performance when performance on water is

known, 2.3: 30, 30f., 31t., 31f., 32t.pump selection for given head and rate of flow,

2.3: 25f., 26f., 26, 27f., 28f.pump selection for given head, rate of flow, and

viscosity, 1.3: 28symbols and definitions, 1.3: 28, 2.3: 22

Viscous response types, 3.1-3.5: 19–22VOCs See Volatile organic compoundsVolatile liquid pump, 1.3: 3Volatile liquids, 5.1-5.6: 24Volatile organic compounds, 9.6.5: 6Volume, 1.6: 3, 2.6: 1, 11.6: 3Volume units, 6.6: 1Volumetric efficiency, 6.1-6.5: 23, 6.6: 5

calculating for hydrocarbons, 6.1-6.5: 47–53calculating for water, 6.1-6.5: 45–47, 48t., 49t.water compressibility, 6.1-6.5: 47, 48t., 49t.


32

Volute pumpscalculation for radial thrust, 1.3: 58calculation of axial thrust for enclosed impellers,

1.3: 60–63circular casings, 1.3: 60, 60f.dual volute casing, 1.3: 58, 59f.K versus rate of flow (double volute casing), 1.3: 58,

59f.K versus rate of flow (single volute casing), 1.3: 58,

59f.single volute casing, 1.3: 58, 58f.

Vortices, 9.8: 1free surface, 9.8: 1, 26, 26f.required submergence for minimizing surface

vortices, 9.8: 29, 33f., 34f.submerged, 9.8: 1sub-surface, 9.8: 26f., 27

Wastewater, 9.1-9.5: 61Wastewater service pumps, 1.3: 14Watches and magnets, 4.1-4.6: 19, 5.1-5.6: 32Water compressibility, 6.1-6.5: 47, 48t., 49t.Water hammer, 1.3: 22, 1.4: 13, 2.4: 11

analysis, 2.3: 14Water lubricated pumps, 2.3: 44Water/wastewater pumps, 9.6.1: 8Waterflood (injection) pumps, 9.6.1: 10Wear plates, 1.4: 15Wear rings, 1.4: 15, 2.4: 14

arrangements, 2.1-2.2: 12f.Welding, 5.1-5.6: 20, 9.1-9.5: 12Well pumping, 1.3: 4Well service, 2.3: 5

Wells, 2.4: 2, 2f.checking, 2.4: 2draw-down, 2.4: 11

Wet critical speed, 9.6.4: 2Wet pit pumps, 2.3: 1Wet pit, short setting or close-coupled (lineshaft)

pumps, 2.1-2.2: 1, 9f.Wet pit volute pumps, 1.1-1.2: 14f.

total suction head, 1.1-1.2: 57Wet wells (solids-bearing liquids), 9.8: 15

cleaning procedures, 9.8: 17confined inlets, 9.8: 16trench-type, 9.8: 16f.vertical transitions, 9.8: 16wet well volume, 9.8: 17

Winding temperature test, 5.1-5.6: 40Working pressure, 1.1-1.2: 60, 2.1-2.2: 23

Yellow brass, 9.1-9.5: 20Yield point, 3.1-3.5: 22Yield value, 9.1-9.5: 6

Z See Elevation headZ See Elevation pressureZinc and zinc alloys, 9.1-9.5: 23Zirconium, 9.1-9.5: 23


I 2002

Documents

9 8 Intake Design (HIS)