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NFPA 20, 2013

Revisions to the Standard

Presenter: Hansford Stewart

To receive credit for this seminar, please sign in on Sign-In sheet & submit a

completed evaluation form. 1

Instructor ¡  Hansford Stewart is the Director of Global Marketing

for A-C Fire Pump Systems. He has been with the company for 40 years focused on stationary fire pumps systems. Hans is honored to serve as a Principal on NFPA 20 Technical Committee. He also serves on UL’s Standard Technical Panel for UL 448 and 1247. In addition, he also serves on Factory Mutual’s Advisory Board.

¡  Hans conducts many NFPA 20 and NFPA 25 seminars around the world. He has published several articles related to fire pump installations, testing, inspection and maintenance requirements.

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DISCLAIMER This seminar and its content is not a formal interpretation issued pursuant to NFPA regulations. Any opinion expressed is the personal opinion of the author and presenter and does not necessarily present the official position of the NFPA and its Technical Committees.

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Paper-Lite In an effort to be environmentally responsible and to increase the quality and timeliness training resources, AFSA is reducing the amount of paper used at our conventions.

The handout file for this seminar can be downloaded at:

www.firesprinkler.org/convention

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NFPA 20, 2013 Edition

Cover image of NFPA 20-13 reproduced with permission from NFPA, Copyright © 2012, NFPA, Quincy, MA.

3.3.25 Where this Code specifies that one equipment shall

be “in sight from,” “within sight from,” or “within sight of,” and so forth, another equipment, the specified equipment is to be visible and not more than 15 m (50 ft) distant from the other.

New Definitions 3.3.25 Where this Code specifies that one equipment shall be “in sight from,” “within sight from,” or “within sight of,” and so forth, another equipment, the specified equipment is to be visible and not more than 15 m (50 ft) distant from the other.

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Pumps in Series ¡  3.3.42 Series Fire Pump Unit: All fire pump units

located within the same building where pump 1 takes suction directly from a water supply and each sequential pump takes suction from the preceding pumps.

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Reliability of Water Supply 4.6.1.2 Where a water flow test is used to determine the adequacy of the attached water supply, the test shall have been completed not more than 12 months prior to the submission of working plans, unless otherwise permitted by the authority having jurisdiction.

Equipment Protection ¡  4.12.1.1.2 Indoor fire pump rooms in non-high-rise

building or in separate fire pump buildings shall be physically separated or protected by fire –rated construction in accordance with table 4.12.1.1.2.

¡  Refer to Table 4.12.1.1.2 ¡  Equipment Protection

¡  Pg. 14

¡  NFPA 20, 2013 Ed.

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Velocity in Suction Pipe

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¡ NFPA 20 has limited the velocity in suction pipe to not exceed 15 ft/sec.

¡  The standard includes minimum pipe sizes based on flow.

¡  The minimum pipe sizes compared to flow provides velocities slightly above 15 ft/sec (15.1-15.3)

¡ Committee decided to delete the 15 ft/sec requirement and add clarification note to the table.

Suction Pipe

¡ OS & Y Valve within 50’ of suction flange

¡ Eccentric Reducer... air pockets

¡ Above ground must be steel pipe, corrosive water conditions painted or galvanized.

¡ No device restricts the pump installed in pumps suction.

¡  If suction supply cannot provide flow of 150% of the rated flow (can provide greater of 100% of rated flow or maximum flow demand) water supply deemed adequate:

1.  Placard indicating min. suction pressure

2.  Required test flow rate

Elbows and Tees ¡  4.14.6.3.3 Elbows and tees

with a centerline plane perpendicular to the horizontal split case pump shaft shall be permitted at any location in the pump suction intake.

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Suction Piping

Suction Elbow

Pump Suction Flange Impeller

Casing Rings Pump Casing

Water Pressure Increases Here Causing a Greater Flow to One Side of the Impeller

Low Suction Throttling Valve ¡ 4.15.9.4 The friction loss through a low

suction throttling valve in the fully open position shall be taken into account in the design of the fire protection system.

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Engine Cooling

¡  4.18.7.2 Where pump discharge water is piped back to pump suction, and the pump is driven by a diesel engine with heat exchanger cooling, a high cooling water temperature signal at 40ºC (104ºF) from the engine inlet of the heat exchanger water supply shall be sent to the fire pump controller and the controller shall stop the engine provided there are no active emergency requirements for the pump to run.

¡  Comment: The recirculation of fire pump water back to pump suction is becoming more and more a problem. We see this as a problem because we use this water to cool not just the engine, as in days of old, but also to cool the engine intake air temperature which is critical to conform to the EPA engine emission requirements. It is tolerable to see raw cooling water up to 95-100°F, but we have seen temperatures of 120 to 150°F plus.

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Engine Cooling 16

Meters and Testing Devices

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Flow Measurement ¡ Refer to Figure A.4.20.1.2(b) ¡  Typical Arrangement for Measuring Fire Pump

Water Flow with Meter. Discharge from the flowmeter is recirculated to the fire pump suction line.

¡  Pg. 66

¡ NFPA 20, 2013 Ed.

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Flow Measurement

Hose Header Location ¡  4.20.3.3.1 A listed

indicating butterfly or gate valve shall be located in the pipeline to the hose valve header.

¡  4.20.3.3.2 A drain valve or automatic ball drip shall be located in the pipeline at a low point between the valve and the header.

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4.27.4.2 Where a backflow prevention device is installed, the final arrangement shall provide effective pump performance with a minimum pump suction pressure of 0 PSI at the gauge @ 150% of rated capacity.

Backflow Preventors

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Packaged Fire Pump Assemblies 22

System Designer

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¡  7.5.1.6.1 The Pump manufacturer shall provide a mass elastic system torsional analysis…critical speeds ±25% operating speed.

¡  7.5.1.6.2 Wetted pump, rated impeller trim, coupling, RAG, shaft and engine.

¡  7.5.1.6.4 For vertical turbine pumps using angle gear drives driven by a diesel engine, a torsional vibration damping type coupling shall be used and mounted on the engine side of the driver shaft.

¡  7.5.1.6.4.1 The torsional vibration damping type coupling may be omitted when a mass elastic system analysis is provided and accepted by the AHJ.

Mass Elastic Systems

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Pump Room Layout

Electric Motors ¡  9.4.4.1 Wiring from the controller(s) to the pump

motor shall be in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, liquidtight flexible metal conduit or liquidtight flexible nonmetallic conduit Type LFNG-B, listed Type MC cable with an impervious covering or Type MI cable.

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Limited Service Controller

¡ 10.7 Remain in the standard with Circuit breaker upgrade. Only difference between Full Service and Limited Service will be the Isolation Switch.

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Batteries

¡  11.2.7.2.1.5 Batteries shall be sized, based on calculations to have capacity to carry the loads defined in 11.2.7.2.3 for 72 hours of standby power followed by three 15-second attempt-to-start cycles per battery unit as defined in 11.2.7.2.1.4, without ac power being available for battery charging.

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Flow Test Requirements 14.2.5.2.3.1 Simultaneous operation of multiple pumps is required for system demand, acceptance test must include a test of all pumps operating simultaneously.

Work Group ¡ Pump room layout.

¡ 20 items are wrong.

¡ Leslie’s drink tickets for person that finds the most.

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Correct Piping ¡ See instructor presentation for answers to

exercise.

Things Wrong ¡ See instructor presentation for answers to

exercise.

Things Wrong ¡ See instructor presentation for answers to

exercise.

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Things Wrong ¡ See instructor presentation for answers to

exercise.

CONCLUSION ¡  Questions & Answers

¡  Evaluations: Paper or Mobile Device ¡  Paper: leave Seminar ID and Attendee ID blank. ¡  Mobile Device: Use a QR Scan application on your

mobile device to scan the QR code before leaving. ¡  A successful scan of the QR code will direct you to

an electronic evaluation form for this seminar.

¡  To receive credit for this seminar, make sure you’ve signed the Sign-In sheet and completed a course evaluation (paper or mobile device).

¡  www.firesprinkler.org/convention

¡  Refer to inside back cover of your convention program for instructions on how to use this QR code to complete an evaluation for this seminar.

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