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Pressure Maintenance (Jockey or Make-Up) Pumps (NFPA 20 Clause 4.27):

Pressure Maintenance (Jockey or Make-Up) Pump. A pump designed to maintain the pressure on the fire protection system(s) between preset limits. Pressure maintenance (jockey or make-up) pumps should be used where it is desirable to maintain a uniform or relatively high pressure on the fire protection system.

Factors such as the nature of the water supply or leakage through the system piping can cause pressure drops or fluctuations within the fire protection system. These pressure fluctuations can cause the fire pump to operate even though the fire protection system has not been activated that is, a sprinkler did not activate, or a standpipe valve was not opened. Fire pumps are not intended to operate for short durations to maintain system pressure.

The benefits of a pressure maintenance pump go beyond maintaining system pressure. A pressure maintenance pump will reduce the likelihood of a pressure surge and thereby improve the effectiveness of waterflow alarms by avoiding false alarms created by pressure surges.


Waterfall Pumps Proposed Vertical Multistage Jockey pump with Cast Iron Casing and Stainless Steel Impeller which will be complying with the NFPA 20 Requirements.


Listing:

4.27.2 “Pressure maintenance pumps shall not be required to be listed. Pressure maintenance pumps shall be approved.”

Selection:


Pressure Maintenance (Jockey or make-up) pumps are generally low-flow, high-pressure pumps. For sprinkler systems, pumps are usually sized to flow a quantity of water less than or equal to that required by a single sprinkler. When sized in this manner, if a sprinkler opens on the system, the jockey pump will start, usually after an additional 5psi (0.3bar) has been lost to friction following the start of the jockey pump.


A rule of thumb for sizing jockey pumps supplying underground piping is to use 1 percent of the fire pump rated capacity and add 10 psi (0.68 bar) to the pressure rating of the fire pump


 Example:

A fire pump with a rated capacity of 1000gpm (3785L/min) @ 100psi(6.9bar)

 Jockey pump flow

1000gpm x 1% = 10gpm

3785 L/min x 1%= 37.8L/min

Jockey pump pressure

Fire pump rating (100 psi) + 10 psi = 110psi

Fire pump rating (6.9 bar) + 0.68 bar =7.58 bar

Therefore, the jockey pump rating would be 10gpm (37.8L/min) at 110psi (7.58 bar).