26 Plumbing Systems & Design • Jan/Feb 2005

NFPA 20: Standard for the Installa-tion of Stationary Fire Pumps for Fire Protection is the governing standard for fire pumps and their installation. Books aren’t often written about National Fire Protection Association standards, but NFPA 20 has an independent reference guide appropriately titled Fire Pump Handbook, published by NFPA and the National Fire Sprinkler Association. Also, numerous articles have been pub-lished and seminars have been held on the subject. Obviously, fire pump instal-lation is quite a popular topic among plumbing and fire protection engineers.

A fire pump’s main function is to receive a set amount of water flow from a certain source at an initial pres-sure and increase that pressure to a desired level. The fire pump enhances the given water supply; it cannot create water. Thus, if a project requires 1,000 gallons per minute and only 500 gpm is available, an auxiliary water source is required. The auxiliary source could be suction tanks, a gravity or elevated tank, ponds, lakes, or other bodies of water.

A complete fire pump system com-prises components between the water supply and discharge pipe to feed sprinklers, standpipes, hose valves,

or other water flow devices. These system’s components include the fol-lowing:• Fire Pump. The fire pump boosts

the water supply’s pressure to a pressure sufficient to operate the fire protection devices properly.

• Fire Pump Driver. The driver is an electric motor or diesel engine device used to supply the power to operate the fire pump.

• Valves and Fittings. These items connect the components to ensure the system is operating properly and allow for testing and servicing of all system components.

• Fire Pump Controller. The con-troller is in charge of starting the fire pump under preset conditions or potentially unfavorable cir-cumstances. The jockey pump, or pressure maintenance, has its own controller.

Installing a Fire PumpBefore you begin to install a fire

pump, make sure you know the answers to the following questions:• What are the applicable codes?

• Does the available water supply meet the facility’s needs?

• Who is providing the water supply to the pump? What are the require-ments or limitations imposed by the water purveyor?

• Is the pump room/house an ade-quate size, does it have a floor drain, and is it heated? Is it accessible to fire fighters and maintenance per-sonnel?

• Who is providing the details of the pump foundation and pump house (if required)?

Also, you must determine several design parameters. First, verify the design conditions: design criteria, required head (pressure), flow require-ments, flow test results, etc. Then, decide the engine type (diesel or electric), whether the pump will be horizontal or vertical, and the electri-cal characteristics (208 volt or 480 volt). Next, locate the test header and determine if a remote alarm panel is required. Finally, ensure the pipe sizing is in accordance with Table 5.25(b) in NFPA 20 (see Table 1).

Flow rates are standardized and range from 300 gpm to 5,000 gpm. Four types of pumps are available: horizontal shaft, vertical inline, vertical turbine, and end suction.

After installing the fire pump, use the checklist on page 28 to ensure all of the components are included and properly assembled. ■

James E. Stenqvist, CPD

Fire Pump InstallationPLUMBING DESIGN by the NUMBERS

James Stenqvist, CPD, is the former president of ASPE’s Connecticut Chapter. Please contact him with your suggestions, comments, or questions at jstenqvist@msn.com.

This article is meant to provide some basic guidelines. Always check all relevant codes and resources for a particular project.

Table 1. Summary of Centrifugal Fire Pump Data (U.S. Customary)

Pump Rating (gpm)

Minimum Pipe Sizes (Nominal)

Suction1, 2 (inches)

Discharge1 (inches)

Relief Valve

(inches)

Relief Valve Discharge (inches)

Meter Device

(inches)

Number and Size of Hose

Valves (inches)

Hose Header Supply

(inches)300 4 4 2½ 3½ 3½ 1-2½ 3400 4 4 3 5 4 2-2½ 4450 5 5 3 5 4 2-2½ 4500 5 5 3 5 5 2-2½ 4750 6 6 4 6 5 3-2½ 6

1,000 8 6 4 8 6 4-2½ 61,250 8 8 6 8 6 6-2½ 81,500 8 8 6 8 8 6-2½ 82,000 10 10 6 10 8 6-2½ 82,500 10 10 6 10 8 8-2½ 103,000 12 12 8 12 8 12-2½ 103,500 12 12 8 12 10 12-2½ 124,000 14 12 8 14 10 16-2½ 124,500 16 14 8 14 10 16-2½ 125,000 16 14 8 14 10 20-2½ 12

1 Actual diameter of pump flange is permitted to be different from pipe diameter.2 Applies only to that portion of suction pipe specified in 5.14.3.4.Source: NFPA 20, Table 5.25: Summary of Fire Pump Data

28 Plumbing Systems & Design • Jan/Feb 2005

Foundation and Setting❑ Pump and driver are securely

mounted with anchor bolts and are grouted.

❑ Pipe strain is not transmitted to pump and valve flanges.

❑ Pump and driver are aligned prop-erly.

❑ A seismic restraint is included (if necessary).

❑ Overhung impeller and impeller between bearings, design pumps, and driver are mounted on a common grouted base plate.

❑ The overhung impeller’s pumps (close coupled inline) are mounted on a base attached to the pump mounting base plate.

❑ The base plate is securely attached to a solid foundation in a way that ensures proper pump and driver shaft alignment.

❑ The foundation is sufficiently sub-stantial to form a permanent and rigid support for the base plate.

❑ The base plate, with pump and driver mounted on it, is set level on the foundation.

Valves❑ A listed outside screw and yoke

gate valve is installed in the suc-tion pipe.

❑ No valve other than a listed OS&Y valve is installed in the suction pipe within 50 feet of the pump suction flange.

Backfl ow Preventers, Check Valves, and Water Supply Protection❑ Check valves and backflow preven-

tion devices and assemblies are listed for fire protection service and meet the water purveyor’s requirements.

❑ Where the backflow prevention device or assembly incorporates a relief valve, the relief valve dis-charges to a drain appropriately sized for the maximum antici-pated flow from the relief valve.

❑ An air gap is provided in accor-dance with the manufacturer’s recommendations.

❑ Water discharge from the relief valve will be readily visible or easily detected.

❑ Engineering calculations and tests document the preceding require-ments’ performance.

❑ A flow control device is installed on the pump suction (if required by the water purveyor). Ensure hydraulic calculations reflect this device’s imposed flow control.

❑ Where located in the pump’s suction pipe, check valves and backflow prevention devices or assemblies are a minimum of 10 pipe diameters from the pump suction flange.

❑ Where the authority having juris-diction requires the installation of a backflow prevention device or assembly in connection with the pump, special consideration has been given to the increased pressure loss resulting from the installation, which is reflected in the hydraulic calculations.

❑ Where a backflow prevention device is installed, the final arrangement provides effective pump performance with a mini-mum suction pressure of 0 pounds per square inch at the gauge at 150 percent of rated capacity.

❑ Engineering calculations and tests document determination of effec-tive pump performance.

❑ If required by the local jurisdic-tion, the suction control valve is mounted in the discharge piping with the sensing line properly piped to the suction supply piping.

❑ If the existing water supply is normally of adequate pressure, a properly installed bypass has been provided.

❑ If the water supply is taken from a raw water source (pond or lake), suction screens and a vortex plate have been installed.

Centrifugal Pump Factory and Field Performance❑ Pump furnishes no less than 150

percent of rated capacity at no less than 65 percent of total rated head.

❑ The shutoff head does not exceed 140 percent of rated head for any type pump.

Centrifugal Pump FittingsThe pump manufacturer has pro-

vided the following fittings:❑ automatic air release valve (not

required on vertical inline or top centerline end suction pumps)

❑ circulation relief valve (not required on water-cooled, diesel-driven pumps and vertical tur-bines)

❑ pressure gaugesThe following fittings are provided

where necessary:❑ eccentric tapered reducer at suc-

tion inlet❑ hose valve manifold with hose

valves❑ flow measuring device❑ relief valve and discharge cone❑ pipeline strainer

Vertical Turbine Pump Fittings

The following fittings are included:❑ automatic air release valve❑ water level detector❑ discharge pressure gauge❑ relief valve and discharge cone

where required❑ hose valve header and hose valves

or metering devices

Pipeline Strainer❑ For pumps requiring removal of

the driver to clean rocks or debris from the pump impeller, a pipeline strainer is installed in the suction line a minimum of 10 pipe diam-eters from the suction flange.

❑ The pipeline strainer is cast or heavy fabricated with corrosion-resistant metallic removable screens to permit cleaning of the strainer element without removing the pump’s driver.

❑ The strainer screens have a free area of at least four times the area of the suction connections, and the openings are sized to restrict the passage of a 0.3125-inch sphere.

Jockey Pump FittingsThe following fittings are included:

❑ suction and discharge butterfly or gate valves

❑ discharge check valve❑ relief valve (only required if the

maximum suction pressure plus the jockey pump’s shutoff head

exceed the fire protection system’s working pressure)

❑ pressure gauges (not required by NFPA 20 but sometimes required by the AHJ and always recom-mended)

Fuel for Diesel Pump❑ Each engine has separate tanks

and fuel lines.❑ The tank(s) is/are exclusive for the

pump(s).❑ The tank is aboveground (gravity

fed).❑ The fuel lines are protected from

damage.❑ The tank and fuel lines are located

in the pump room (preferred).❑ Fuel lines and fittings are cast

iron or stainless steel (no copper, galvanized steel, bronze, or brass).

❑ The appropriate grade of diesel fuel is marked on the fuel tank.

❑ A method for indicating the fuel tank level other than sight glasses is provided.

Electric Motor❑ Electric motor is listed for fire

pump service.❑ Electric motor nameplate HP and

voltage matches the controller nameplate HP and voltage.

Electric Controller❑ Controller is within sight of the

fire pump.❑ The correct controller type—full

voltage (across the line), wye delta, part winding, primary resistor, auto transformer, or limited service—is supplied per specifications.

❑ The fire pump controller has no thermal protector at the service entrance. (Any short circuit or disconnecting equipment must indefinitely hold 600 percent of the motor’s full load amps and be lockable in the closed position.)

❑ The controller is not being used as a junction box to supply power to other loads in the pump room.

❑ The transfer switch (if supplied) has been wired to the backup generator.

❑ A main relief valve is installed if a variable speed pressure limiting controller is provided.

PLUMBING DESIGN by the NUMBERS

Checklist for Fire Pump Installation❏✘✘❏✘❏

Jan/Feb 2005 • Plumbing Systems & Design 29

❑ There are no other means of disconnecting power to the pump (such as a disconnect switch).

Diesel Engine❑ Engine has proper fluids (oil and

coolant).❑ Engine jacket water heater is

wired and functional.❑ Fuel and water solenoids are prop-

erly wired to the instrument panel.❑ Engine instrument panel is wired

to the fire pump controller.❑ Batteries have been charged for

24 hours.

❑ Adequate ventilation is available to maintain design pump room temperature and adequate air supply.

❑ Pipe hangers (not the engine) support the exhaust piping.

❑ Engine muffler is installed properly and exhaust piping ter-minates in an approved location and manner.

Diesel Controller❑ Controller is within sight of the

fire pump.

The following local alarm indica-tors are functional:❑ low oil pressure❑ high temperature❑ failure to start❑ overspeed shutdown❑ battery failure❑ battery charger failure❑ low fuel level

Pressure Control Sensing Lines❑ Sensing lines are of copper, brass,

or bronze construction.

❑ Sensing lines are one-half-inch nominal diameter.

❑ Sensing lines for each pump are independent (including all fire pumps and jockey pumps).

❑ Sensing lines have two one-half-inch check valves with 3∕32-inch holes in the clapper.

❑ Each check valve is separated by a minimum five feet of sensing line.

❑ No shutoff valves are in the sens-ing lines.

Publisher’s Note: ASPE and PSD do not directly or indirectly endorse products or manufacturers. Material present in this magazine is for furthering the technical interests of plumbing engineers, designers, contractors, and other interested professionals. From time to time a product may be mentioned, or an article or the material from a professional or specialist from a product manufacturer may be presented.The presentation of this type of material is in no way an endorsement of the American Society of Plumbing Engineers or of Plumbing Systems & Design magazine. The material has been reviewed by PSD professionals who provide technical editing services to the Society and is deemed to be of sufficient or significant interest to the plumbing industry and profession.

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