Pump & System - Feb 2016

8/18/2019 Pump & System - Feb 2016

1/60

FEBRUARY 2016

PUMPSANDSYSTEMS.COM

The Leading Magazine for Pump Users Worldwide

SYSTEMS

K A L A M A Z O O R I V E R R E M E D I A T IO N D I V E R T S 5. 9 B I L L IO N G A L L O N S | 3 Q U E S T I O NS A B O U T U SI N G I oT

SMARTPUMPINGEnhancing security & increasing

uptime with intelligent controls

8/18/2019 Pump & System - Feb 2016

2/60

Circle 100 on card or visit psfreeinfo.com.

8/18/2019 Pump & System - Feb 2016

3/60

pumpsandsystems.com | February 2016

C i r c l e 1 0 1 o n c a r d o r v i s i t

p s f r e e i n f o . c o m .

8/18/2019 Pump & System - Feb 2016

4/60

8/18/2019 Pump & System - Feb 2016

5/60Circle 103 on card or visit psfreeinfo.com.

8/18/2019 Pump & System - Feb 2016

6/60

February 2016 | Pumps & Systems

30 ALTERNATIVE TECHNOLOGIES CONTROL COMPLEX PUMPING PROCESSES & SYSTEMS

By Jeff Payne, AutomationDirect.comPLC-based PACs ll the gap between traditional distributed controlsystems and basic programmable logic controllers.

34 INTELLIGENT PUMP CONTROL REDUCESENERGY CONSUMPTION BY 80 PERCENT

By Martin Hoffmann, Colfax Fluid Handling/Allweiler

A ame retardant manufacturer incorporatedfrequency converters to control its cooling waterpumps.

38 3 QUESTIONS TO ASK BEFORE IOT

IMPLEMENTATION By Jon Hilberg, Accudyne Industries—Precision Flow Systems

A well-planned systems approach to predictiveanalytics using cloud connectivity can optimize pumping systems.

COVERS E R I E S

2 FROM THE EDITOR

6 NEWS

53 PRODUCTS

54 PUMP USERS MARKETPLACE

56 PUMP MARKET ANALYSIS

MART PUMPING

PUMPING PRESCRIPTIONS

12 By Lev Nelik, Ph.D., P.E. Pumping Machinery, LLC

Using Pump Effi ciency Monitoring toMake Faster Decisions

PUMP SYSTEM IMPROVEMENT

15 By Ray HardeeEngineered Software, Inc.

Troubleshooting a Piping SystemFirst of Two Parts

COMMON PUMPING MISTAKES

18 By Jim Elsey Summit Pump, Inc.

Solid Shaft Designs & Cartridge Seals

INDUSTRY INSIGHTS

22 By Mike Pemberton Pumps & Systems

Intelligent Pumping Continues to Evolve

COLUMNS

This issue FEBRUARYVolume 24 • Number 2

PUMPS & EQUIPMENTFOR HARSH CONDITIONS

24 LIQUID-LUBRICATED DOUBLE SEALS INCREASE STABILITY FOR PTAPRODUCTION

By Andreas Pehl, EagleBurgmann Germany Gmbh & Co. KgOne facility’s high-speed centrifugal pumps saw improved performance and effi-

ciency after adding custom seals.

27 MATCH HYDRAULIC FLUIDS TO SEAL LIP MATERIALBy Stephen A. Maloney, Colonial Seal Company

Companies interested in reducing safety hazards and environmental impact shouldconsider compatibility issues.

S P E C I A L

S E C T I O N

PRACTICE & O PERATIONS

48 PUMPING SYSTEM DIVERTS 5.9BILLION GALLONS OF WATERFOR KALAMAZOO RIVERREMEDIATION

By Duane Hargis, Cornell Pump Co.

& Rich Goethals, BakerCorp

DEPARTMENTS

40 EFFICIENCY MATTERSPeristaltic Pumps Offer Protection in

Mining Operations

By Tom O’Donnell, Abaque, part of PSG

42 MAINTENANCE MINDERSCreative Coupling Design Saves

Downtime at Utility Plant

By Jim Anderson, Coupling Corporation

of America

44 SEALING SENSEWhat to Consider When Upgrading or

Changing Pre-Specified Gaskets

By Mike Shorts, FSA Member & President

46 HI PUMP FAQSSubmersible Vertical Turbine Pump

Intake Designs, Common AC Single-

Phase Motors

By Hydraulic Institute

50 MOTORS & DRIVESObtain Maximum Bearing Life &

Performance

By Mike Pulley, Bartlett BearingCompany

48

34

8/18/2019 Pump & System - Feb 2016

7/60

pumpsandsystems.com | February 2016Circle 102 on card or visit psfreeinfo.com.

8/18/2019 Pump & System - Feb 2016

8/60

6 NEWS


NEW HIRES,PROMOTIONS & RECOGNITIONS

RICH GREATTI

FLUID SEALING INTERNATIONAL

CORAOPOLIS, Penn. (Jan. 5, 2016) – FluidSealing International has announced that RichGreatti has joined the company as directorof sales and marketing. Greatti brings morethan 30 years of experience in the fluid sealing

industry in sales, engineering and businessdevelopment with a successful track recordthat includes international sales, product development as well asmanaging a global sales force. He has helped develop several newsealing products and a successful distribution/direct/OEM network inthe fluid sealing industry. worldfsi.com

CHUCK KELLOGG, HUBBARD-HALL

WATERBURY, Conn. (Dec. 11, 2015) – Hubbard-Hall Chairman/CFOChuck Kellogg has received the prestigious Lifetime AchievementAward at the annual meeting of the National Association of ChemicalDistributors (NACD). Kellogg was one of the founding members ofNACD in 1971 when he and other CEOs recognized the need for thechemical distribution industry to adopt best practices and becomeovert stewards of the chemical distribution process. Kellogg hasremained active and vocal in the association since its founding. hubbardhall.com

BOB LAUSON, PSG

OAKBROOK TERRACE, Ill. (Dec. 9, 2015) – PSG, a Dover company,has appointed Bob Lauson to general manager for PSG Grand Rapids(Blackmer). In this role, Lauson will be responsible for leading theGrand Rapids organization and will report directly to PSG PresidentKarl Buscher. He will be based out of the PSG Grand Rapids facilityin Grand Rapids, Michigan. Lauson joined PSG from Terra SonicInternational, where he held the position of president. psgdover.com/en/blackmer/home

ALEXANDER SEVERT

& JIARAN SUN

WATER PLANET

LOS ANGELES (Dec. 7, 2015)

Water Planet has furtherexpanded its engineering teamwith the addition of AlexanderSevert as mechanical anddesign engineer and Jiaran Sunas research and development engineer. At Water Planet, Severt willprovide modeling, fabrication and design support to the membraneand system design team. Sun will assist with the developmentand commercialization of Water Planet’s PolyCera polymer andmembranes. waterplanet.com

HEATHER GREEN, APPLETON GROUP

ROSEMONT, Ill. (Dec. 4, 2015) – Heather Green has been promotedto director of product marketing for Appleton Group, a division ofEmerson. In this role, Green will work with product management, theengineering team and global sales for the division’s brands Appleton,O-Z/Gedney and others to achieve success across multiple industries.She will report directly to Tim Graff, vice president of engineering for

Appleton Group, within the engineering organization. As leader ofthe product management team, Green will guide Voice of Customerresearch, identify customer value propositions, define platformstrategy, establish product requirements and improve supportingoverall business processes. emersonindustrial.com

MYLA PETREE

BALDOR ELECTRIC COMPANY

FORT SMITH, Ark. (Nov. 24, 2015) – BaldorElectric Company has appointed Myla Petree tothe newly created position of director – strategicprogram management. In this role, she anda recently formed team of project managerswill be responsible for organizing, driving andsuccessfully implementing key projects across avariety of Baldor locations and products. Petree joined Baldor in 2011as the company’s director of quality. Petree has a bachelor’s degreein mechanical engineering from the University of Oklahoma and is anASQ Certified Manager of Quality/Organizational Excellence.baldor.com

Rich Greatti

JiaranSun

Alexander

Severt

Myla Petree

MERGERS & ACQUISITIONS

8/18/2019 Pump & System - Feb 2016

9/60

7

pumpsandsystems.com | February 2016Circle 104 on card or visit psfreeinfo.com.

8/18/2019 Pump & System - Feb 2016

10/60

8 NEWS


STW Resources Holding CorpReceives Approval for WaterPermit in West TexasMIDLAND, Texas (Dec. 16, 2015) – STWResources Holding Corp., a provider ofpipeline services, water reclamationand processing management servicesincluding water desalination, hasreceived approval from the MiddlePecos Water District for drilling,production and transportation of thewater on STW Water’s MRK lease inPecos County. Previously, STW Waterapplied for a consolidated drillingand production permit from the San

Andrés formation to be utilized withinthe county and exported out of PecosCounty to surrounding areas in need ofwater. The company also has the abilityto submit a request to the water districtfor a larger permit once it is determinedby a hydrogeologist that theformation can withstand an increasein yield without any negative effects.Additionally, with several prospectivebuyers already in place, STW canbegin selling water immediately. Thecompany anticipates water sales in thefirst quarter of 2016, as it has alreadyreceived a letter of intent from acustomer to purchase water.

stwresources.com

Xylem Supplies Technologyfor Vital Connector Routein EuropeLANAYE, Belgium (Dec. 10, 2015)Xylem has designed a water pumpingsolution as part of a complex project toexpand the Lanaye Locks in Belgium, avital connector route between Northernand Southern Europe. Xylem’s Flygtpumps and turbines will regulate waterlevels in the canal network and harness

energy from excess water in the AlbertCanal. The addition of a fourth Lanayelock (225 x 25 meters) will quadruplethe lock system’s convoy capacityfrom 2,000 to 9,000 tons. The pumpingsolution, which includes five Flygt 500kilowatt submersible hydroturbineswith a flow of 18 cubic meters persecond, pumps water back into theAlbert canal, maintaining adequatelevels to accommodate canal trafficduring dry weather spells. xyleminc.com

Siemens Joins Notre Dameto Develop $36 MillionTesting FacilityATLANTA (Dec. 9, 2015) – Siemenshas announced that it will supply theUniversity of Notre Dame with the mainmotor and variable frequency drivefor its new Turbomachinery Facility.The facility will be a research and testfacility for advancing the technologyused in gas turbine engines used by thecommercial and military aircraft, powerplant, and the oil and gas industries.Siemens will provide a 10-megawattSINAMICS SM120 variable frequency

drive and a 5-megawatt SIMOTICSAboveNEMA TEWAC motor.

siemens.com

KLINGER Holding GmbH FormsKLINGER IGI Inc.VANCOUVER, Wash. (Dec. 1, 2015)KLINGER Holding GmbH in Austria hasannounced the formation of KLINGERIGI Inc. as an addition to the group’sindustrial gasketing presence in theU.S. Headquartered in Wilsonville,Oregon, with an additional locationin Denver, Colorado, the seals and

gasketing manufacturer is a result ofKLINGER’s acquisition of IGI.klinger-international.com

China Leads World in PrivatelyFunded Water InvestmentBOSTON (Dec. 1, 2015) – China is firmlypositioned as the global epicenter forprivately financed water investment.The combined water infrastructurebuild-out across 20 provinces accountsfor more than 50 percent of privatelyfinanced treatment capacity addedin emerging markets over the lastdecade. According to a new report

from Bluefield Research, China’swastewater treatment market hasadded more than 20 million cubicmeters per day of capacity from 2013-2015. The level of annual investmenthas surged to more than $5 billionin 2014. As a result, private firmsnow manage about two-thirds ofthe country’s wastewater treatmentinfrastructure. bluefieldresearch.com/china-municipal-wastewater-

market-private-player-opportunities-

strategies-2015-2020/

Massachusetts WaterResources Authority MovesForward with Pump SystemOptimization ProgramPARSIPPANY, N.J. (Nov. 30, 2015)Massachusetts Water ResourcesAuthority (MWRA), which provideswholesale water and sewer services to2.5 million people and more than 5,500large industrial users, conducted anin-house Pump System Optimization(PSO) Program in November 2015as a precursor to a pump systemassessment of all its facilities. ThePSO Program was developed by the

Hydraulic Institute for engineers,operations, facilities, maintenanceand management personnel toeducate their staff about operatingpump systems more efficiently. A.W.Chesterton Company and WEG ElectricCorp. co-hosted this particular pumpsystem optimization training course. mwra.com

World’s Largest 5-TurbineCommercial Tidal InstallationPut into ServiceDEN OEVER/SCHIEDAM, The

Netherlands (Nov. 26 2015) – The tidalpower plant in the Dutch EasternScheldt surge barrier has been putinto service. The commissioning forthe largest tidal energy project in theNetherlands as well as the world’slargest commercial tidal installation offive turbines in an array was performedby Diederik Samsom, Dutch LabourParty group chairman. tocardo.com

CENTA and Christie & GreyLimited Announce GlobalSales Cooperation

AURORA, Ill. (Nov. 16, 2015) – Themanagement teams of CENTA AntriebeKirschey GmbH and Christie & GreyLimited have announced a strategicglobal sales cooperation between theircompanies. The agreement allowsthe two companies to join forces toengineer and strategically supplythe industry’s premium “quiet drive”solutions—combining soft mountingsystems, flexible couplings andintermediate drive shaft systems. centa.info christiegrey.com

AROUND THE INDUSTRY

To have a news item considered, please send the information to Amelia Messamore, [email protected].

8/18/2019 Pump & System - Feb 2016

11/60

9


PRESSURE?NO PROBLEM.

7020 Series

Q U A L I T Y . S E R V I C E . I N N O V A T I O N . I N T E G R I T Y .

1-800-928-7867 | www.zoellerengprod.com

The Shark ® 7020 Series Progressing Cavity

Grinder Pumps are ideal for pressure sewer

systems. For commercial and residential

sewage removal with high head requirements,

these pumps have an integral pressure reliefvalve. Packages designed for new installations

and retrofitting existing systems. Designed,

machined, assembled in the USA. Cast iron,

Cool Run™ design is fully submersible.

100% factory tested.

YOUR PEACE OF MINDIS OUR TOP PRIORITY.®


8/18/2019 Pump & System - Feb 2016

12/60

10 NEWS


FEBRUARY 24, 20161 P.M. EASTERN

Sponsored by

January 28, 2016 How to Read a Pump Curve (now available online)

February 24, 2016 Efficient Pump Selection and Control

March 23, 2016 Introduction to Boiler Feed Systems

April 27, 2016 Choose the Right Pump for the Application

May 18, 2016 Vertical Turbine Pumps - Wire-to-Water

June 22, 2016 Dosing Basics

F R E E

A 6-PART WEBINAR SERIES

Efficient PumpSelection andControlTHE SECOND IN A 6-PART WEBINAR SERIES FOR 2016

pumpsandsystems.com/2016/grundfos

Sign up today for this webinar and the entire series!

With more focus on energy efficiency these days, building owners

will rely on pump experts to assist in the determination of efficient

pumping solutions. For variable flow systems this poses some

challenges when single and parallel connected variable speed pumpsare evaluated. This webinar will help to answer questions like: “How

many pumps should our system use?” and “How should we sequence

(stage) on additional pumps?”

Presenter Reece Robinson has a bachelor of

science degree in mechanical engineering from

California State University Fresno. He has more

than 16 years experience providing variable

speed pumping solutions and energy analysis for

commercial, municipal and industrial applications.

Participants will receive a certificate to submit for CEU credits!

8/18/2019 Pump & System - Feb 2016

13/60

11


C i r

c l e 1 0 9 o n c a r d o r v i s i t p s f r e e i n f o . c o m .

EVENTSThe Process Heat Exchangers:Applications & Rules-of-ThumbShort CourseFeb. 1 – 2, 2016HTRI HeadquartersNavasota, Texas979-690-3250

20th Annual ARC Industry Forum –Industry in Transition: Navigatingthe New Age of InnovationFeb. 8 – 11, 2016Renaissance Orlando at SeaWorldOrlando, Florida781-471-1175 / arcweb.com

Maintenance Planning &SchedulingFeb. 17 – 19, 2016San Francisco, California203-783-1582 / newstandardinstitute.com/product/maintenance-planning-and-scheduling/

WQA Convention & ExpositionMarch 14 – 17, 2016

Music City CenterNashville, Tennessee630-505-0160 / wqa.org/convention

Offshore Technology Conference(OTC)May 2 – 5, 2016NRG ParkHouston, Texas972-952-9494 / 2016.otcnet.org

2016 EASA ConventionJune 12 – 14, 2016

Metro Toronto Convention CentreToronto, Ontario314-993-2220 / easa.com

National Fire Protection Association(NFPA) Conference & ExpoJune 13 – 16, 2016Mandalay Bay Convention CenterLas Vegas, Nevada800-344-3555 / nfpa.org/training/ events-calendar

8/18/2019 Pump & System - Feb 2016

14/60

Using Pump Efficiency Monitoring to MakeFaster Decisions

In 2015, I wrote a series

for Pumps & Systems titled

“Effi ciency Monitoring Saves

Plants Millions.” I gave readers

a real-world example of the

importance of understanding how

equipment is performing. Below,

I answer a question from a reader

about the effectiveness and speed

of plant monitoring systems.

Letter from a Reader

“I enjoyed your four-part series

(Pumps & Systems, July, August,

September and October 2015)

relating the dynamics of what goes

on at the plants in an interesting

real-world dialogue format. You

started the set by introducingthe reader to a pump salesman,

Bob, who visits the water plant

and works with a local plant

maintenance manager, Jim, on

measuring the effi ciency of his

large pumps. Other people get

involved along the way, and the

amount of savings they discovered

shocked me—nearly $125,000

for a 3,000-horsepower pump. In

Part 1 of your article series, you

said the entire test was done inless than a day by a system you

referred to as “PREMS,” but you

did not describe what it is. We have

plant monitoring systems in our

plant, but they cost millions, and

I doubt that anything, no matter

how simple that may sound, can be

done in a day. Can you elaborate?”

Jack Francis

Chemical plant employee

Chicago, Illinois

Nelik’s Response

Tank you for your question. It

does not surprise me that the

amount of wasted energy seemed

so high to you. Most folks think

more about a piece of machinery’s

reliabil ity than about its effi ciency.

Te thought process is, “If a pump

fails too often, water spills a ll over

the plant, and I get home late for

dinner.” Tat is personal. But to

look at a running pump to see 10

percent effi ciency being wasted,

that is often too abstract.

But the numbers are there—

in dollars instead of red ink on

a pump housing. Consider the

3,000-horsepower (hp) pump

in the articles you mentioned.

Multiplying 3,000 hp by 0.746 gives

us 2,238 kilowatts. Multiply that

by 24 hours for 365 days, times

$0.10 per kilowatt-hour, and it

adds up to $2 million. If 10 percent

is wasted, that is $200,000. Te

$125,000 in the articles is adjusted

for the pump running less than 100

percent of time.

Figure 1 (above). Live data streaming in. Figure 2 (below). Spectral (FFT) data is taken and

displayed continuously by the PREMS system.

12 PUMPING PRESCRIPTIONS


By Lev Nelik, Ph.D., P.E.

Pumping Machinery, LLC, P&S Editorial Advisory Board

Troubleshooting & repair challenges

8/18/2019 Pump & System - Feb 2016

15/60

For details of how to measureeffi ciency, let me do a brief review.

In March 2007, Pumps & Systems

published “How Much Energy is

Wasted When Wear Rings Are

Worn to Double Teir Initial

Value?” Double was picked because

that is the point where most

original equipment manufacturers

(OEMs) recommend replacement

of rings. But such repairs are

costly. Users do not know the worn

dimensions until they pull thewear rings from the pump.

By measuring effi ciency

continually, they can pinpoint the

time when the effi ciency value

drops below the value that justifies

the repair and restoration of the

ring clearances to the initial OEM

recommended values. Continuousmonitoring reconstructs the entire

performance curve, because most

pumps do not “sit” at the same

flow. In response to changes in

the system, the flow changes, and

pressure, power and effi cienc y

change with it.

A dynamic, live reconstruction

of the performance curve does not

require intrusive periodic testing.

Continuous monitoring makes the

performance curve more accurateand detailed over time. It would

also tell where the plant typically

runs—something that plants

often do not know.

In regard to the pump’s

reliabil ity and effi ciency

measurement system (PREMS)

in Part 1 (Pumps & Systems,July 2015), the key to a good

technology is accuracy and

simplicity. Te PREMS is

essentially a box, similar to a

suitcase, that can be installed

for one pump, monitoring it for a

period of time, and then moved as

needed to another pump.

Te system transmits through

a wireless cell gateway (or a

local modem), alleviating any

concerns of interfering withthe plant operational system.

Instrumentation measures

pressure, flow and amps, which the

software converts into a complete

pump performance curve (head-

capacity, power and effi ciency) that

is displayed on the screen.


13


8/18/2019 Pump & System - Feb 2016

16/60

Examining the data over time

reveals that the pump operatesmainly in two regions (see Figure

1, page 12). One region is near

the best effi ciency point, but the

other is much closer to the shutoff

head (below minimum continuous

stable flow). Te second region is

in the area where internal forces,

pulsations and vibrations are

detrimental to the pump. Vibrations

are measured continually, including

overall values and spectral (Fast

Fourier ransform, or FF) data

to troubleshoot live. Te chart

on Figure 2 (page 12) shows the

first and second harmonics being

predominant (1X and 2X). What

does it tell us? Email me your

answer from the following choices

for a chance to win a discounted

seat at the next Pump School.

a. Rotor unbalance

b. Misalignmentc. Cavitation

d. Both a and b

e. a, b and c

Using Figure 1, we can compare

the original OEM performance,

shown with solid lines, to actual

performance, shown with multiple

data points outlining the evolving

curves. Te system provides stand-

alone data acquisition, combining

instrumentation with software,

to present a real, standard pump

curve—live and continually.

Interpretation of data is simple—it

is on the screen. Te difference in

effi ciency is calculated continually

and translated into yearly prorated

dollars wasted. Tis data can

help users decide between repair

(yearly energy cost vs. repair cost),

adjustments to the system or no

action (if energy cost is smallrelative to the quoted repair cost).

For more information, email

me or visit Pump Video Academy

online at pumpingmachinery.

com/pump_school/PVA/pva.htm

(modules #10 and #11).

T F S E A L S U S A . C O M

We Deliver!

[email protected]

Phone: 1.713.568.5547

Fax: 1.713.758.0388

10620 Stebbins Cir, Suite E

Houston, TX 77043

Serving Manufacturers and Distributors Over 30 Years!

PZ05

metal bellow cartridgemechanical seal

TF-P241

packing Nomex fiberand graphite PTFE

TF-P214

packing 100% PureGraphite PTFE yarn


Dr. Nelik (aka “Dr. Pump”)

is president of Pumping

Machinery, LLC, an Atlanta-

based firm specializing in pump

consulting, training, equipment

troubleshooting and pump

repairs. Dr. Nelik has 30 years

of experience in pumps and

pumping equipment. He may

be reached at pump-magazine.

com. For more information, visit

pumpingmachinery.com/pump_

school/pump_school.htm.

14 PUMPING PRESCRIPTIONS


8/18/2019 Pump & System - Feb 2016

17/60

A better understanding of complete system operation

Troubleshooting a Piping System

First of Two Parts

Using the example system

in Figure 1, this series

will focus on the process

elements found in piping systems.

In this example, a process fluid

is pumped from a storage tank,

PX-K-120, through an end suction

pump, PX-PU-120, specified to

pass 800 gallons per minute (gpm)

with 202 feet of head. From the

pump discharge, the 80 F process

fluid travels to a heat exchanger,

PX-HX-121, where the fluid is

heated to 120 F. Level control

PX-LCV-120 maintains the level

in process vessel PX-PV-122 to 15

feet. Te system boundaries are

the tanks PX-K-120 and PX-VP-

122. Te system contains only onecircuit. able 1 lists the physical

properties of the process fluid.

Less than six months ago, a

piping system model was created

and validated using the installed

plant instrumentation (values are

shown in Figure 1). Te difference

between these values and the

calculated results was less than

2 percent.

Te piping drawing shows that

the flow rate through the systemis controlled to maintain the level

in the process vessel PX-PV-122 at

15 feet. Te system does not have

an installed flow meter, so we must

determine the system flow rate.

One of the easiest methods

is to use a portable clamp-on

ultrasonic flow meter. If operated

correctly, these devices can provide

accuracy of ±1 percent. During

the assessment, the flow meter

indicated a flow rate of 770 gpm.

In a previous column, we

discovered that the flow rate

through a pump can be calculated

by converting the differential

pressure to head. Using the pump

curve, enter the value for pump

head on the vertical axis and movehorizontally until you intersect the

pump curve. Ten move down to

determine the flow rate.

Figure 1. Example system consisting of the items making up the systemalong with displayed operating data (Graphics courtesy of the author)

Table 1. Physical properties of the process fluid used in this example

Fluid Temp (F) Density (lb/ft3 ) Viscosity (cP) Vapor press (psia)

Process fluid 80 48.9 0.30 8.8

Process fluid 120 47.3 0.25 16.4

Table 2. Comparing as observed conditions with cavitation to validated results

Condition/Value PX-TK-120

ft

PX-PI-120

psi

PX-PI-121

psi

PX-LCV-120position*

PX-PV-122

level

PX-PV-122psi

Current Operation 5 -2.0 65 78% 15 20

Validated 5 0.4 69.6 69% 15 20

* The value position is not on the operator’s log sheet.

NPSHa =

Formula 1

NPSHa = (-2 + 14.7 - 8.8) x =11.5 ft

Where:P

in = Suction pressure psig

Patm

= Atmospheric pressure psia

Pvp

= Fluid vapor pressure psig

Ρ = Fluid density lb/ft3

144

ρ(P

in + P

atm - P

vp) x

144

48.9

Equation 1

15


By Ray Hardee

Engineered Software, Inc.

8/18/2019 Pump & System - Feb 2016

18/60

In this example, the differentialpressure across the pump is 69.2 pounds

per square inch (psi). Using a process

fluid density of 48.9 pounds per cubic

foot (lb/ft3), we can determine a pump

head of 203.8 feet.

Te manufacturer’s supplied pump

curve shows that, with a head of 204

feet, the flow rate through the pump

is 770 gpm. Te flow rate calculated

through the pump correlates with the

flow rate obtained with the ultrasonic

flow meter.

Now that we have discussed how the

model was validated with the observed

values, we can troubleshoot.

An operator notifies the shift

supervisor that pump PX-PU-120

sounds like it is cavitating. Additionally,

the pump discharge pressure gauge is

oscillating, another indication of possible

pump cavitation. able 2 shows thesystem’s current operation along with

the validated results.

able 2 shows that the levels and

pressures at the system boundary tanks

are the same in both conditions, resulting

in the same static head. Te pressure at

pump suction pressure PX-PI-120 is -2

pounds per square inch gauge (psig), 2.4

psi less than the validated results. Te

pump discharge pressure PX-PI-121 is 67

psi, 2.6 psi less than the validated results.

According to able 2, the position of

PX-LCV-120 is 78 percent open, greater

than the validated results.

Te first step is to determine if these

conditions are the cause of cavitation.

Using Equation 1, we will determine

the net positive suction head available

(NPSHa) at the pump suction based on the

pressure gauge reading at PX-PI-120.

As indicated in Figure 1, the NPSHais 11.5 feet. Te pump curve shows that

the net positive suction head required

(NPSHr) is 14.3 feet. As a result, the

NPSHa is greater than the NPSHr,

indicating pump cavitation is occurring.

Because the pump is cavitating, the pump

is probably not operating on its curve.

Part 2 of this series will use the

data discussed here to determine the

cause of cavitation and analyze other

system problems.

Ray Hardee is a principal founder of

Engineered Software, creators of PIPE-FLO

and PUMP-FLO software. At Engineered

Software, he helped develop two training

courses and teaches these courses

internationally. He may be reached at ray.

[email protected].

BOOTH

5429


16 PUMP SYSTEM IMPROVEMENT


8/18/2019 Pump & System - Feb 2016

19/60

17


C i r c l e 1 5 1 o n c a r d o r v i s i t p s f r e e i n f o . c o m .

8/18/2019 Pump & System - Feb 2016

20/60


This month’s column

focuses on whether to use

shaft sleeves in overhung

centrifugal pumps (ype OH-1

per American Petroleum Institute

[API] 610 designation). Te mostcommon OH-1 pump type is the

American National Standards

Institute (ANSI) B73.1M. Te

practice of using cartridge-type

mechanical seals on solid pump

shafts (in lieu of sleeved shafts)

is not new or radical. While the

benefits of building a pump in this

manner are real and measurable in

most instances, a large percentage

of pump owners will not change.

Background

I would estimate that shaft sleeves

have been used on pump shafts for

at least 100 years. My 1919 edition

of Pumping Machinery by Arthur M.

Greene mentions “sacrificial shaft

liners.” I do not know exactly when

the first pump shaft sleeve was put

into service, but I assume it was

not long after someone adjusted

the packing incorrectly on an

expensive pump.Shaft sleeves serve multiple

purposes. Te most important is to

protect the main pump shaft from

wear caused by packing abrasion,

followed closely by prevention of

erosion and corrosion. In some

pump designs, the sleeve serves

additional purposes. For example,

in some horizontal split-case

pumps, the sleeve also serves

(in conjunction with a threaded

shaft nut) as an adjustable means

to axial ly locate the impeller on

its respective mechanical and

hydraulic center in the casing.

Te sleeve is designed to be the

inexpensive and replaceable part.

It is easier and less expensive tochange a sleeve than the whole

shaft. Users who have packing in

their pump consider the sleeve a

must-have design feature.

In 1905, the mechanical seal

as we know it was invented, but

it was not commonly used until

after World War II. Fifty years

ago, most centrifugal pumps in

industrial and commercial services

stil l had packed stuffi ng boxes.

Pumps with mechanical sealswere uncommon and expensive.

Later in the 1970s, many users

began to use simple mechanical

seals because of safety concerns,

stricter Environmental Protection

Agency (EPA) regulations, and the

cost of both lost product and flush

fluids. Tese simple seals were

eventually displaced by component

type mechanical seals. Prudent

pump users continued to use

the existing shaft sleeve designsbecause the component seals

were held in place by tightening a

number of set screws. Te torqued

set screw points damaged the shaft

sleeve surface. Tese “dog marks”

(damaged metal surfaces) from

the set screws were an accepted

negative side effect because of

the shaft sleeve’s status as an

inexpensive and replaceable part.

In recent years, most pump users

have switched to cartridge-type

mechanical seals. Most present-day

designs will not damage the shaft

or shaft sleeve during instal lation,

operation and subsequent removal

from service. Even O-ring fretting

of the shaft or shaft sleeve iseliminated in most new designs.

By Jim Elsey

Summit Pump, Inc.

Solid Shaft Designs & Cartridge Seals


18

Simple solutions for end users

Figure 1. An example of stiffness ratiocalculations ( Graphics courtesy of the author )

Figure 2. An example of a sleeved pumpshaft design with ample diameter tomaintain a low stiffness ratio

8/18/2019 Pump & System - Feb 2016

21/60

When the American Voluntary Standards

(AVS) pumps and the forerunners ofthe modern ANSI pump (B73.1M) were

designed in the late ’50s and early ’60s,

packed stuffi ng boxes were standard. If

these pumps were to be redesigned today,

they would use cartridge-type mechanical

seals, and the design length of the shaft

from the radial bearing to the impeller

would be shorter.

When a packed pump is operating, the

packing acts like an additional line bearing

because of the hydrodynamic properties

of the close clearances between the shaftsleeve and the packing. Tis “consequential

and beneficial phenomenon” mitigates shaft

deflection caused by any unequal radial

forces acting on the impeller.

Without packing around the shaft (for

example, when a seal is used), the shaft

will deflect more, especially if the pump

is not operating near the best effi ciency

point/best operating point (BEP/BOP).

Pump operation at or near shutoff (far left

side of the curve) and at runout conditions

(far right side of the curve) away from thepreferred operating region results in shaft

deflection, which causes premature bearing

and mechanical seal face wear, shortening

the life of these critical components.

Te ability of a shaft to resist deflection

is a direct function of the overhung length

and the shaft diameter. Tis is commonly

referred to as the shaft stiffness ratio,

shaft deflection ratio, or the L over D ratio

(L3 / D4). Te lower the ratio number, the

better the shaft wi ll resist deflection. Te

formula for calculating the ratio factoris based on the simple cantilevered beam

deflection formula.

Many of the factors in the beam

deflection formula cancel each other out

when applied to an overhung pump shaft.

As a result, the revised formula is simply

the length (L) of the shaft as measured from

the centerline of the radial bearing position

to the centerline of the impeller (take L to

the third power) divided by the diameter

of the shaft in this area (D) to the fourth

power, or L3 / D4 (see Figure 1).

Measure Flowfrom Outsidethe Pipe

Designed for dirty or aerated liquidslike wastewater,slurries, sludgeand liquids with

bubbles or solids

Non-Contacting Flow Measurement

and Control

888-473-9546 [email protected]

www.greyline.com

Works with a clamp-on sensor for pump

protection, flow control and high or low flowalarms. bargraph displays flow rateThe LEDand relay state.

DFS 5.1 Doppler Flow Switch

Low-Flow or No-Flow

Pump Protection

DFM 5.1 Doppler Flow Meter

The clamp-on ultrasonic sensor installs inminutes without shutting down flow. Start-upis easy with the built-in keypad and simplemenu system.

C i r c l e 1 1 3 o n c a r d o r v i s i t p s f r e e i n f o . c o m .


19

8/18/2019 Pump & System - Feb 2016

22/60


A smaller shaft diameter results in

a higher stiffness ratio, which is nota desired attribute. Without delving

into a protracted formula derivation,

the strength of the shaft material is of

little importance, but the modulus of

elasticity (Young’s modulus) does come

into play. Most common shaft materials

share similar ranges for the modulus of

elasticity. If pump shafts are breaking,

the cause is usually cyclic fatigue, not

material strength. So a stronger material

is not the answer, but preventing or

reducing deflection is.

When a pump is purposely designed

to incorporate a shaft sleeve, the

original shaft diameter in the packing

and mechanical seal area is typically

machined down to a smaller diameter

of some incremental distance (D) to

accommodate the corresponding sleeve.

Some manufacturers’ processes design

and machine the shaft differently. Eitherway, the end result is that the shaft has

a smaller diameter on the overhung

portion. Te smaller diameter yields

a higher shaft deflection ratio, which

means the shaft will deflect more for a

given radial force. More deflection will

result in deleterious effects on the seal

and bearings.

Note that the presence of the sleeve

does not contribute to the stiffness

factor, no matter how tight the fit. Te

sleeve is not an integral part of the

shaft and does not become a factor in

the equation.

In the past, most pump shafts

were generously over-designed/sized

to transmit some amount of torque

(horsepower) at some speed range, but

most shafts were not designed for high

side loads (like belt or chain drives) and

cyclic fatigue factors. Current designsare taking these side load factors more

into consideration.

Current Practices

Many pump owners continue to use old

design shaft sleeves when using new

design cartridge mechanical seals. Tere

are some good reasons, such as corrosion/

erosion mitigation, for continuing this

practice. In most cases, however, there

is no other reason than “that is the

way we have always done it.” I would

say that, for a given system (curve) and

the consequential pump operation on

its curve, the pump life would be much

longer if the shaft design was solid versus

sleeved. Te pump would be more reliable,

and the mean time between failure and

repair (MBF/R) would be longer.


20


8/18/2019 Pump & System - Feb 2016

23/60

In some modern OH-1 pump models,

the incorporation of a shaft sleeve isby design and is an acceptable practice

because the shaft deflection ratio is

already very low as a result of a generous

shaft diameter in the sleeve area. X-17

ANSI pumps (ANSI sizes A105, 110 and

120) are one example (see Figure 2,

page 18).

Many pump manufacturers also

offer solid pump shafts that are made

of different materials in the wetted

(sacrificial) versus non-wetted areas.

Furthermore, most ANSI pump

manufacturers offer an optional shaft of

larger diameter for given midrange sizes

(for example, M, or medium-sized shaft

and bearing systems, versus L, or large

sized, models).

Even with sleeve construction, the

deflection ratio between the two models

of different shaft diameters is significant.

Te difference between the smaller (M)sleeved shaft and a larger (L) solid shaft

is dramatic.

ANSI B73.1M has set tolerances for

allowable shaft deflection at the stuffi ng

box area of the shaft over the allowable

operating range.

Pumps in compliance with this

specification are not allowed more than

0.002 inches of deflection. Simply

looking at the L/D ratios is one way

to evaluate the pump, but it is equally

important to calculate the radial loads for

your specific operation and the resultant

shaft deflection.

Shaft runout, or total indicator

reading, with a sleeve design is harder tocontrol because of the added surfaces and

associated tolerances. Te allowable shaft

runout on a solid shaft is 0.001 inches

and 0.002 inches for a sleeved shaft. As

a final design note, any sleeve design

needs to allow for thermal expansion and

contraction.

Even when we know we should

implement change, some habits are hard

to break.

Are you operating your overhung

pumps with cartridge seals and still

using shaft sleeves? I would like to

hear why.

Jim Elsey is a mechanical engineer who has focused on rotating equipment design and

applications for the military and several large original equipment manufacturers for 43

years. He is the general manager for Summit Pump, Inc., and the principal of MaDDog

Pump Consultants LLC. Elsey may be reached at [email protected].


21


8/18/2019 Pump & System - Feb 2016

24/60

An intelligent pump is

more than a pump; the

product is a combination

of a pump, process instrument(s)

and variable frequency drive

(VFD) with related intelligenceembedded in the microprocessor

motherboard. While variable speed

drives (VSDs)—both mechanical

and electronic—have been applied

to pumps for decades, the drives

on intelligent pumps were the first

commercially available VFDs that

used pump protection logic to alert

end users during upset conditions.

oday, several manufacturers offer

intelligent pumps with vary ing

performance monitoring andasset protection capabilities. An

intelligent pump also typically

includes standard process control

functions, such as proportional-

integral-derivative control (PID)

and power (kilowatt) consumption

monitoring.

Te first intelligent pump was

introduced near the beginning

of the new millennium. Tis

technology has been instrumental

in changing many facets of thepump industry. One change has

been the development of a new

understanding that control valves

do not have to be the de facto

flow control device for pump

systems. Embedding pump

intelligence into VFDs also has

led to the view that the pump—

along with the instrumentation

and control valves—is a key

component of industrial

automation architecture.

Advantages ofIntelligent Pumping

From a process control standpoint,

the primary difference between

a VFD and a control valve is that

the VFD electronically changesmotor speed to maintain flow,

pressure, level or temperature at

set-point, while the control valve

mechanically adjusts its opening to

meet process control requirements.

Both approaches maintain process

flow at the required rate but differ

significantly in how they impact

energy use, equipment reliability

and process control performance.

VFD speed reduction lowers head

(pressure) at the square root ofspeed, while flow is reduced at the

cube root of speed. For example,

a small reduction in speed can

result in a moderate head reduction

and large energy reduction. Te

reduction in head (pressure) and

the accompanying reduction

in energy usage are primarily

the result of fully opening or

eliminating the control valve.

Standard and intelligent VFDs

provide the same level of energysavings but can differ significantly

in the amount of maintenance

savings they provide. Embedded

pump protection can alarm, slow

down or turn off the pump when

the system encounters conditions

such as dead-heading, dry-running

or cavitation.

Te introduction of intelligent

VFDs signaled the rise of variable

speed pumping as an a lternative

to control valves, especially in

continuous process industries.

For the first time, end users could

use the electronic platform as a

“brain” that learns and adapts

pump performance to changing

process conditions. Tis real-timeadaptability plays a critical role in

achieving process sustainability

through uptime, controllability

and reliability improvements. An

intelligent pump offers far more

information about the pump’s

performance than was ever readily

available in the past.

Limitations to Adoption

While plant operators and

engineers typically configurestandard VFDs through a keypad

or laptop in the motor control

center (MCC), the PID algorithm

and control logic in the VFD are

infrequently used. Normally, the

control engineers opt for using the

same control functions that found

in the distributed control system

(DCS). Te DCS then outputs a

speed signal back to the VFD over

an analog cable (4-20 mA), a step

similar to sending an analog signalto a valve positioner to change the

percent that it is open or closed.

Digital bus communication can be

used, but the majority of plants

built before the new millennium

use analog signals to communicate

from the DCS to the field

instruments and valves.

Because the VFD and DCS are

in different locations, operators

and engineers are often unable

to configure the intell igent pump

Intelligent Pumping Continues to Evolve

22 INDUSTRY INSIGHTS


By Mike Pemberton

Pumps & Systems Senior Technical Editor

Trends & analysis for pumping professionals

8/18/2019 Pump & System - Feb 2016

25/60

firmware from the DCS. Tisrestriction causes the embedded

pump intelligence in the VFD to

be underutilized.

While this was an issue with

the first generation of intelligent

pumps, the growth of wireless

communication, the Industrial

Internet of Tings (IIo) and cloud

computing have made it possible

to overcome these limitations.

oday, multiple parameters can

be transmitted from the MCCto the DCS. Access to the pump-

protection logic from the DCS can

lead to more visibility and higher

utilization rates.

An alternate approach

could be to use a third-party

software package with the pump

intelligence and load that program

on the DCS. Tis could make theintelligent pump compatible with

multiple VFD brands and different

voltage ratings. Te end user could

purchase the VFD separately from

software package and combine the

two using wired or wireless digital

communication. In this scenario,

the pump intelligence could access

the DCS database as well as receive

data from the VFD. By accessing

data from both control elements,

the level of intelligence couldpotentially be expanded.

While intelligent pump

technology has made significant

advances in asset protection, the

use of wireless communication,

cloud computing and/or third-

party software offers new

approaches that can increase

the availability and utilizationof pump intelligence. Te DCS

and related information systems

could be able to both configure

and display multiple capabilities,

including the following:

• Alarm and control actions

with data logging, time

stamps and trends

• Real-time pump and

system curve visibility with

mechanical effi ciency

• Real-time horsepower and/or kilowatt consumption and

specific energy

Mike Pemberton is the senior

technical editor for Pumps &

Systems. He may be reached at

[email protected].

WHY MONITOR POWER INSTEAD OF JUST AMPS?

NO LOAD NO LOAD

Power is Linear-Equal Sensitivity

at Both Low and High Loads

No Sensitivity

For Low Loads

FULL LOAD FULL LOAD

P O W E R

A M P S

WWW.LOADCONTROLS .COM

CALL NOW FOR YOUR FREE 30-DAY TRIAL 888-600-3247

PROTECT PUMPS A MONITOR PUMP POWER

TWO ADJUSTABLE SET POINTS

4-20 MILLIAMP ANALOG OUTPUT

COMPACT EASY MOUNTING

UNIQUE RANGE FINDER SENSOR

PUMP POWER

PUMPING

VALVE CLOSING

VALVE OPENINGNO FLUID


23


8/18/2019 Pump & System - Feb 2016

26/60

24


he production of purified terephthalic acid

(PA) poses unique challenges for centrifugal

pumps. For increased safety and reliability, some

facilities with this process have incorporatedcustom-engineered liquid-lubricated double seals. Tis

new technology meets the ever-increasing product

performance requirements of leading PA producers.

HP reactor feed pumps—in many cases, integrally

geared high-speed centrifugal pumps—play a vital role

in the purification stage of crude terephthalic acid (A).

Tese pumps deliver A slurry, which contains A powder

suspended in demineralized water at a high temperature,

into a hydrogenation reactor, where a reaction with

hydrogen removes contaminants from the solution.

PA is the predominant raw material for production

of high-purity polyester resin, which is widely used inthe production of polyester fiber, polyethylene

terephthalate (PE) bottle resin, polyester film and

engineering plastics.

Operational reliability of the HP reactor feed pumps

is critical for maintaining stable operation of PA

purification plants, and mechanical seals are among the

most critical pump components because of high-speed

and high-pressure service requirements.

In one particular application—for one of the world’s

largest PA producers—the selected centrifugal pump

was configured as a horizontally mounted, integrally

geared two-stage pump with a single double-ended output

shaft, which operates at a rotational speed of 6,200

revolutions per minute (rpm) with impellers attached on

each end. Te two stages are piped up to operate in series

to develop the required head rise, and the first-stagedischarge feeds the second-stage pump suction. Tis

setup boosts the Stage 2 seal chamber pressure to 80 bar,

or 1,160 pounds per square inch (psi).

Te seals for the application were engineered as a

cartridge-design double seal face-to-face arrangement

for Stage 1 and as a tandem oriented face-to-back dual

seal arrangement for Stage 2, which splits the total

differential pressure between two seals and maintains

suitable pressure velocity (PV) parameter levels. Te

seal support system utilizes flush supply to both pump

stages, which helps to protect the product side seals from

plugging with A slurry.

Technical Challenges

One of the main technical challenges in this application

pertained to the barrier/buffer fluid. Instead of using

the more common ambient-temperature demineralized

water as a barrier/buffer liquid that is usually supplied

from the PA plant centralized seal-support system, the

facility requested to use plant return water at the normal

temperature of 70 degrees C (158 F), with a maximum

temperature of 80 C (176 F). Te potentia l problem

with using plant return water as barrier/buffer liquid

under these conditions is an adverse seal environment

SPECIAL SECTION

PUMPS & EQUIPMENT FOR HARSH CONDITIONS

8/18/2019 Pump & System - Feb 2016

27/60

25

pumpsandsystems.com | February 2016pumpsandsystems.com | February 2016

characterized by inadequate heat dissipation and poor

lubrication of seal faces resulting from a loss of fluid film

from vaporization.

An additional technical challenge was reverse

pressurization of the Stage 2 process side seal during

pump startup and shutdown. During the startup

sequence, this seal is reverse-pressurized by the buffer

fluid introduced into the seal support system before

the pump main driver is turned on. Under transient

conditions, while the pump is ramping up to full speed

and reaching full discharge pressure, the pressure applied

to the seal is reversed, causing the seal to hang up. Te

same problem occurs in opposite order during pump coast

down to shutdown. Te original seal design was modifiedto incorporate new features to overcome seal hang-up

associated with the secondary seal.

Te demanding requirements of this facility required

an application-specific solution. Once the performance

specification had been drawn up, the development and

design stage began. Te seal and pump manufacturers’

teams met to analyze the operating points in detail.

Tis provided precise performance calculations and a

computer-aided design for the sliding elements.

Te new double seals were based on a special

high-pressure seal from the manufacturer’s existing

product portfolio. Specifically, the team opted for the

effi cient high-pressure seal. In contrast to conventional

mechanical seals from the standard range, high-pressure

seals have one important special feature: the seat

rotates on the shaft while the seal face—with its spring

backing—is stationary in the housing. Tis seal concept

provides additional stability at high speeds. At sliding

velocities of 20 meters per second (66 feet per second)

or more, the springs should be stationary so they do not

absorb vibrations and deform.

Optimized Design

Design improvements to the seal technology, including

the use of ultra-high-performance materials, were made

to guarantee stable running across the entire operatingrange. While the regular seals use silicon carbide ceramic

material for both seal face and stationary seat, the

stationary seal face for this application was based on the

silicon carbide variant BuKa 30. Tis material has a high

carbon content, making it an ideal solution for media

with poor lubricating properties, such as water. BuKa 30

impresses with its effective emergency running properties

and tolerance to dry running.

Te seal was further optimized to guarantee functional

reliability, even in the marginal ranges. A loosely fitted

seal face provides additional safety against tipping and

tilting. Another technical feature of the high-pressure

Image 1. Pump in operation (Image and graphic courtesy of EagleBurgmann)

8/18/2019 Pump & System - Feb 2016

28/60

26 PUMPS & EQUIPMENT FOR HARSH CONDITIONSSPECIAL SECTION


seal developed for the PA application is the

incorporation of high-precision grooves in the seal faces.

Te depth and geometry of these grooves were specified

with accuracy. At low pressure, the grooves promotelift-off of the seal faces by creating a positive pressure

cushion, and they quickly establish a stable operating

state. At high pressure, the grooves have a stabilizing

effect because they prevent the gap from opening further.

Field Tested

Combining all these measures resulted in sophisticated

sealing systems in both tandem and back-to-back

versions. Tese cover the range of applications up to 100

bar (1,450 psi) and 9,000 rpm and ensure functional

reliability. Te liquid-lubricated double seals cope with all

operating parameters, and constant sealing performanceis reliable, even when exposed to considerable pressure,

temperature and speed fluctuations.

Te seals, which are designed as easy-to-fit cartridge

systems, were extensively tested and confirmed in

dynamic test runs in the test field. Te new double seals

have also proven their worth in the many integrally

geared pumps that were bought into service in China in

2014 in one of the world’s largest PA facilities.

Andreas Pehl is technical sales support for mechanical

seal applications at EagleBurgmann

Germany in Wolfratshausen. He joined

EagleBurgmann in 2010. He has a degree in

industrial engineering from the University

of Applied Sciences, Munich. For more

information, visit eagleburgmann.com.

Figure 1. Double seal in tandem arrangement. Theyellow parts are rotating, blue are stationary, andgray shows the shaft and housing.

Circle 137 on card or visit psfreeinfo.com.Circle 139 on card or visit psfreeinfo.com.

8/18/2019 Pump & System - Feb 2016

29/60


27

n the sealing industry, compatibility influences the

ability to form a chemically stable system. Using

the wrong hydraulic fluid could result in a violent

reaction that is disastrous for the entire hydraulic

assembly. Te fix is not simple; it could cost thousands of

dollars in repairs and lost production time. o avoid these

problems, users should ensure that the lip material or

sealing material is compatible with planned media. Any

biodegradable upgrades or media improvements must

also be compatible with the sealing elastomer.

Each year the U.S. uses about 200 million gallons

of hydraulic oils. Of this volume, approximately 165

million gallons are mineral-based fluids. Tese types

of mineral-based oils function at temperatures as low

as -40 C to as high as 150 C with some exceptions.

When choosing the right fluid, it is essential to assess

physical and performance properties along with any

original equipment manufacturer (OEM) approvals or

specifications. Most fluid suppliers should be able to

provide a product data sheet so that the design engineercan discern the best solution for the application.

Mineral-based fluids include specialty fire-resistant

hydraulic fluids and environmentally friendly,

biodegradable fluids. Te International Organization for

Standardization (ISO) acknowledges four major groups

of fire-resistant hydraulic fluids: high-water containing

fluids (HFA), invert emulsions (HFB), water glycols (HFC)

and water-free fluids including synthetics (HFD).

Along with being fire-resistant, the chemical

characteristics of HFA fluids are almost identical to that

of plain water. As a result, this type of fluid is typically

used in equipment that has been intended for use with

water and is subjected to an open flame. HFA fluids

are most commonly used in steel mills and coal mines.

However, because these are fire-resistant fluids and not

fire-proof fluids, HFA fluids can still ignite and burn,

given the right conditions.

HFB fluids are made up of emulsions of water caught

in oil with 60/40 oil-to-water composition. Tis type offluid can sometimes perform to the level of petroleum oil

and offers greater lubrication and corrosion resistance

compared with HFA fluids. Its water content also acts as

an extinguisher in case of a fire.

Te most frequently used fire-resistant hydraulic

fluid category is water glycols (HFC). While these fluids

are comprised of only 35-45 percent water, they also

include unique thickeners that boost viscosity. While

HFC fluids can be used to run equipment designed for

oil, severe damage to machine parts can occur due to an

overwhelming environment if the speeds, temperatures

or pressures are not monitored properly.

SPECIAL SECTION

Image 1. It is important to consider how hydraulic fluids will af fectthe hydraulic seal. (Graphics courtesy of Colonial Seal Company)

8/18/2019 Pump & System - Feb 2016

30/60


28 SPECIAL SECTION

HFD fluids are classified as synthetic

because they contain neither petroleum

oil nor water. Polyol esters have an

organic makeup that is biodegradable.HFD fluids are also compatible with

system materials and provide exceptional

hydraulic fluid performance. However,

HFD fluids are more than double the cost

of petroleum oil and are typically only

used when the situation demands fire

resistance and biodegradability.

Because governments have become

more vigilant with environmental

regulations, it is increasingly important

to use a more eco-friendly fluid. For a

product to be labeled an “environmentallyacceptable fluid,” more than half of it

must decay within 28 days of exposure

to the atmosphere. Te fluid must be

nontoxic after passing a series of aquatic

toxicity tests on fish. Te most common

base for these environmental fluids is

vegetable oil (or more specifically canola/

rapeseed oil). Although they cannot

be used as a direct replacement, the

lubrication and anti-wear properties will

be comparable to those of petroleum oil.

While eco-friendly fluids are becomingmore available, the problem is that none

of the current options can be used as

a direct replacement in hydraulically

powered equipment. Tere are drawbacks

to using a minimally toxic hydraulic fluid.

Tese fluids may be more vulnerable to

oxidation and have a poor performance

record in extreme cold weather, resulting

in coagulation and problems cold

starting. o increase stability and prevent

problems with viscosity, vegetable

oil producers have turned to geneticengineering to al leviate problems with

biodegradable fluids.

If a plant decides to change the

hydraulic fluid used in an assembly,

personnel must consider the

compatibility of the replacement fluid

with the internal components of the

machinery, ensuring that the seal lip

material is compatible with the chosen

application media. Tese materials range

from standard nitrile Buna rubber, Viton

and ethylene propylene diene monomer



Variable Speed Controls for Pumps

When a standard off the shelf drive will not meet your needs, KB will work

with you to develop a custom drive solution, Ready to Use “Out-of-the-Box.”

Provides variable speed control for AC Induction, DC, PMSM and EC motors, 1/50 to 5 HP.

115, 208/230, 400/460 VAC – 50/60 Hz 1ø and 3ø Input.

KB Electronics, Inc.12095 NW 39th Street, Coral Springs, FL 33065-2516

Designed and

Assembled in USA

8/18/2019 Pump & System - Feb 2016

31/60


29

rubber to polytetrafluoroethylene

(otherwise known as eflon).

Understanding how a seal material will

interact with various fluids is the first

step to finding the right match.

When choosing hydraulic

oil, consider both viscosity and

temperature. o prevent early internal

component failure, the viscosity grade

must match the operating temperature.

Te quality of the hydraulic should not

be a factor; if it is not compatible, a

system failure could result.

If the operating temperature of a

hydraulic system is below the suggestedlevel for the viscosity grade, the fluids

can congeal. Solidified oil will not

flow freely through the system, which

can cause component seizures. Te

solidification can cause media to lose

the ability to lubricate the hydraulic

piston and increase the coeffi cient of

friction undergone by the seal lip. Te

increased wear and heat will cause the

seal lip to quickly deteriorate.

When switching to an eco-fr iendly

hydraulic fluid, be prepared fordifferent results from the interaction

of the seal lip material and the fluid.

Eco-friendly fluids can cause a shorter

life for a traditional nitrile seal.

Fluorocarbon is the best material

for users who go this route. Always

check with the fluid supplier before

switching. Because biodegradable fluids

have a different chemistry composition

than petroleum-based fluids, the

interaction with the seal lip materials

could be an issue.

In a real-world example, a user

experiencing premature hydraulic

seal failure thought he had been sent

either the wrong seal or the incorrect

seal material. Te seal provider

discovered that the user had switched

to a fire-resistant hydraulic fluid so

that he could create a safer working

environment. No research was doneon how this change would impact

his machinery and its components,

including the seal.

Te result was that the ethylene

propylene diene monomer seal was

not compatible with the new fluid.

Te seal was absorbing the fluid at an

accelerated rate, causing the seal lip to

swell. Tis swelling caused increased

wear on the seal, resulting in decreased

seal life and unacceptable leakage.

Contact your fluid or seal supplier forreference charts. Tey will have first-

hand compatibility knowledge.

Table 1. Fire-resistant hydraulic fluids and their features

ISOClassification

Makeup H2OContent

ISOTemperatureRange

Comments

HFA High-watercontaining

fluids

Less than80%

5 to 50 C Chemical characteristics aresimilar to water.

HFB Invertemulsions

Less than40%

5 to 50 C Because of its water content,it can act as an extinguishershould a fire occur.

HFC Waterglycols

Less than35%

-20 to 50 C The most commonly usedhydraulic fluid

HFD Water-freefluids,includingsynthetics

None -20 to 70 C The chemical makeup issynthetic, and the fluidcontains no water or oil and issafe for the aquatic ecosystem.


Stephen A. Maloney founded Colonial Seal Company in 1994. He retired as a colonel

in the U.S. Marine Corps in 2008. He has a Bachelor of Science in management

and technology from the U.S. Naval Academy and a Master of Science in systems

management from the University of Southern California.

8/18/2019 Pump & System - Feb 2016

32/60

ecause of the complicated nature of pump

flow and pressure control, industrial plants

have often incorporated control of complex

pumping and related systems using distributedcontrol systems (DCSs) or expensive specialized

controllers. In the past, many programmable logic

controllers (PLCs) were not up to the task, so engineers

and designers turned to DCSs or similar controllers,

which, in some cases, can lead to higher costs and

complex implementation.

oday, new alternatives allow monitoring and control

of these complex systems with programmable automation

controllers (PACs), saving considerable expense and

simplifying implementation.

Te PAC, or PLC-based PAC, fills the gap between the

DCS and basic PLC. It has the hardware and softwarerequired to monitor, control and communicate with these

pumping systems (see Figure 1, page 32).

Advanced Process Control

Complex pumping systems often require advanced

process control (APC), which goes beyond proportional-

integral-derivative (PID) control and can include methods

such as model predictive control, inferential control and

sequential control.

PID is sometimes insuffi cient because the process that

needs to be controlled has a long dead time, is non-linear

or presents other diffi cult ies.

Various APC control methods and algorithms are

supported in DCS platforms but not in most PLCs.

PLC-based PACs, on the other hand, can execute many

APC algorithms and typically have some built-in APC capability.

Some APC methods require complex custom coding, a

programming technique supported by DCS platforms but

not by most PLCs. Te PLC-based PAC solves this problem

because it allows users to create custom code, encapsulate

it and integrate it into the overall controller program.

When APC is required, a PLC-based PAC provides many

of the capabilities of a DCS but at a lower cost and with

simpler implementation. Pushing a basic PLC to perform

APC is impossible in some cases, and even high-end

PLCs can require an extraordinary amount of effort to

implement APC.

Interfacing to Instruments

Pumping systems for applications such as custody

transfer often contain a large number of instruments

and analyzers. ypical instrument types include flow,

pressure, temperature and density. Many of these

instruments are multivariable, measuring several

parameters at once. Modern pumping systems often

employ smart instruments with a built-in, two-way

digital data link, rather than simple instruments with

a 4- to 20-milliamps (mA) output proportional to the

measured variable.

30 COVER S E R I E S SMART PUMPING


8/18/2019 Pump & System - Feb 2016

33/60

For example, custody transfer applications often use

mass flow meters because they can precisely measure

the amount of liquids transferred from one owner to

the next regardless of product density. Coriolis meters

measure multiple variables including flow, density and

temperature and are most commonly used to measure

mass flow.Tese variables are sent to the control system along

with diagnostic, calibration and other information.

A typical Coriolis meter used in custody transfer will

transmit hundreds of parameters to the control system

over a digital data link, presenting data storage and

handling chal lenges.

Plants often employ analyzers to measure parameters

related to the chemical composition of oil and other liquid

hydrocarbons. Like smart instruments, analyzers are

usually connected to the control system via a two-way

digital data link and often transmit more than a hundred

parameters to the control system.

Complex pumping systems commonly employ smart

valves. Like smart instruments and analyzers, smart

valves communicate large amounts of data with the

control system over two-way digital data links.

A DCS will have built-in communication capabilities

for a number of the process control protocols used by

smart instruments, smart valves and analyzers. While aPLC will have more limited communications capabilities,

a PLC-based PAC will have an extensive array of built-in

communication ports and protocols, with the ability to

expand through plug-in communication modules.

Data Handling

Smart instruments, smart valves and analyzers

produce large amounts of data (see Image 1). A DCS

can handle the storage and processing of this data, but

a PLC generally cannot. A PLC-based PAC provides the

needed data capabilities at a lower cost and with simpler

implementation than a DCS.

Image 1. Each of these smart Coriolismass flow meters provides hundredsof parameters of information relatedto measurement, diagnostics andcalibration. A PLC-based PAC iswell-suited to interface with theseinstruments and to handle the largevolumes of data they produce. (Images

courtesy of AutomationDirect.com)

31


8/18/2019 Pump & System - Feb 2016

34/60

8/18/2019 Pump & System - Feb 2016

35/60

8/18/2019 Pump & System - Feb 2016

36/60

erman company ICL-IP Bitterfeld

GmbH has been producingphosphorus-based flame retardant

since 1997. Its plant in Bitterfeld-

Wolfen employs about 80 people. Many of the

steps in the production process—from the

phosphorus and chlorine starting materials

to the final products (phosphate ester)—

involve exothermic reactions. Much of the

released heat is led away in water-cooled heat

exchangers. A centralized cooling tower runs

almost continuously—about 8,250 hours per

year—to provide the required cooling water.

Water temperature varies seasonally from19 to 25 degrees C. Te flow rate can be as

high as 1,100 cubic meters per hour (m3/h),

resulting in a cooling capacity of up to 6

megawatts (MW).

In 2011, plant managers analyzed

the processes in the cooling tower. Tey

discovered that the three cooling water

pumps running in parallel ran continuously

against throttle flaps, even under partial-load

conditions and reduced thermal loads in the

plant. It resulted in an unfavorable hydraulic

operating point and poor effi ciency.

Image 1. The three cooling water pumps with a capacity of 360 cubic meters per hour andmaximum delivery head of 52 meters ( Images courtesy of Dr. Kurt-Christian Tennstädt )



8/18/2019 Pump & System - Feb 2016

37/60

Termal utilization of the cooling tower

normally fluctuates between 50 and 100

percent as a result of seasonal factors andvaried usage by individual consumers

during normal operations. Average

utilization is about 70 percent.

Energy Effi ciency a Core Concern

A 2014 company-wide program to improve

energy effi ciency systematically identified

additional weak points in how energy is

used. For the cooling water pumps, new

motors and speed control with frequency

converters produced significant savings.

With this foundation, ProductionManager Dr. Jürgen K. Seifert developed a

technical concept for controlling the three

pumps in a way that adapts to the cooling

water’s continually changing needs while

eliminating the ineffi cient method of using

throttle flaps. Before implementation,

multiple simulations indicated a high

potential for savings with a projected

return on investment (ROI) of two years.

Te pump control is central to the

new concept. Te system utilizes three

frequency converters and includes cascadefunctionality. Te 75-kilowatt (kW) IE4+

synchronous reluctance motors achieve an

effi ciency of 96 percent, an improvement

over previous motors (built in 1996) with

about 90 to 92 percent effi ciency. Tey

even run effi ciently under partial load. As

a result, procurement costs are amortized

in two to three years. Experience in a

previous round of optimizations showed

that converting control over the cooling

tower fans to frequency converters also

achieved significant savings.

Frequency Converters Replace

Manual Intervention

In the past, the pumps ran at a constant

1,450 liters per minute (l/min). Tey were

regulated with throttle flaps located at

the pump outlet on the discharge side.

Tis configuration brought the pumps

into the performance curve range where

the drive motors were not overloaded

(counterpressure at the consumer side is

only about 3.5 bar at full hydraulic load).

Vapor Recovery? LPG Transfer? Natural Gas Boosting?

The answer is the FLSmidth® Ful-Vane™ rotary vane compressor!

Built robustly for long service life, it has only three moving parts. Combined with low operating speeds

which minimizes wear and vibration, it is designed to not only outlast other compressors, but save you

money on power and maintenance costs.

• Suitable for natural gas, flare gas, bio gases, LPG vapor, and ammonia refrigeration

• Carbon fiber vanes last longer than traditional blades

• Variable flows with VFD and/or bypass

• Single stage to 3000 SCFM, two-stage to 1800 SCFM

• Discharge pressures to 250 PSIG

• Made in the USA for over 80 years

Simple, Reliable

Efficient

Find out more at www.flsmidth.com/compressors


Image 2. At the main cooling tower, the fourth pump at the far right is a reserve pumpand it is not automatically included in control.

35


8/18/2019 Pump & System - Feb 2016

38/60

While this type of control can destroy energy, it is

usually unavoidable in situations that consist of a fixed-speed pump and a system with low counterpressure. In

this case, the throttle flaps helped hold the pressure at

a constant 4.8 bar at the pump outlet, regardless of the

actual need for coolant. Tis achieved a constant power

consumption at the motors of 68 to 75 kW, at which

point each pump was expected to stabilize near its rated

capacity of 360 m3/h.

As an initial energy-saving measure after the analysis,

one or two pumps were switched off during partial-load

operations, such as when consumers (heat exchangers)

were turned off. But this approach is diffi cult because

the remaining pumps must be monitored continuously

to make sure they do not become overloaded. If loads

suddenly change, engineers must be prepared to

undertake rapid manual interventions.

Frequency converters help solve this problem by

replacing manual, inconsistent on/off control with a

continuous, intelligent adaptation of pump speeds to

the actual need for cooling water. As a result, manual

interventions are no longer needed. Te pumps are

synchronized and run continuously in their optimal

range, and pump discharge pressure remains constant.

Te cascade feature automatically switches pumps on and

off as requirements change on the consumer side.

Smooth Switch

Te facility completed the practical execution of theupgrade in close contact with the pump supplier. Te

manufacturer has long developed intelligent controllers

for cooling water pumps in systems where the need

for cooling water frequently changes, whether due to

fluctuating cooling water temperature or because of

varying loads imposed by the process.

Because of this experience, the manufacturer was

able to quickly provide a suitable solution for the plant.

“Only rarely have I experienced such a smooth project

execution,” Dr. Seifert said about the experience at the

plant. “Tey immediately understood our concept and

executed it with precision.”

Te upgrade and reconditioning of the three water

pumps was completed within the facility’s one-week

production downtime window. Te manufacturer even

recalculated the impellers and replaced them with the

maximum size impellers. Te optimized impellers, which

are driven at the optimal speed, allow the pumps to

achieve an effi ciency of 85.3 percent.

After only one month, the power costs for the cooling

tower were several thousand euros lower than before.

Because of this success, the facility has short-term plans

to convert other pumps with dynamic requirements to

this control concept.

Image 3. The numerous heat exchangers at various locations in the plantare connected to the main cooling tower with lines of different lengths.This places elevated demands on the intelligence of the pump controller.A specific minimum preliminary pressure must be ensured even at themost distant cooler and in every operating state. Pump output and speedare displayed on the control panel.

CASE STUDY AT A GLANCE

Challenge

• Significantly reduce energy costs

• Convert the entire cooling system within one week

• Flexible pump speed with constant dischargepressure to all consumers

• Elimination of valves; no change to coolingreliability at full load, even if one pump fails

Solution

• Use frequency converters to control the pumps forprecise adaptation of capacities to current need forcoolant

• Optimization of impellers in the centrifugal pumps

Results

• Energy savings of more than 80 percent

• Several thousand euros saved after just one month

• Savings in operation of the cooling tower

• Efficiency of all pumps increased to 85.3 percent



8/18/2019 Pump & System - Feb 2016

39/60

otentialfor Savings

In

many

cases, energy consumption in

such

systems plays only a secondary

role

and

is

often

neglected. Even

at the

Bitterfeld plant,

energy

costs make up a

comparatively

small proportion of overall

production costs. But

the

new controller

reduced power requirements for cooling by

50 to

60

percent, or

about 1,000

megawatt

hours (MWh) yearly. The investment paid

for

itself

within one year,

faster

than

predicted by

the

simulations. Even when

all

three

pumps are

running under

full

load,

energy

requirements drop from 75

to 37

kW

per pump

. The

energy required

to run

the

cooling

tower

now

accounts

for

a much smaller proportion of

the total

energy

consumption of the plant . All

of

the

money that is saved flows

directly

into

operating

results

.

The

Bitterfeld plant

demonstrates

the

potential for savings that

can be found

in

industrial systems with oversized pumps

that

were

dimensioned

and installed years

ago with excess reserves . In

this

case,

the

energy

savings totaled

more

than 80

percent

. As prices for

frequency converters

drop

and the

technology

becomes

more

accessible,

the

use

of

Documents

Pump & System - Feb 2016