Booster Fire Pump without Jockey Pump 1

[DenverFPE]

Hello All,

I am working on a small facility project in which we are installing a wet pipe sprinkler system. In order to meet pressure/flow demands of the system, we are providing a small (750 gpm/50 psi) pump to supplement the available city water supply. I have concluded that we do not need a jockey pump due to the available static pressure in the city water main (98 psi @ 530 gpm), which should be more than adequate to maintain pressure in the system piping. In addition, using the recommended sizing guidelines for a jockey pump provided in NFPA 20H, the recommended size of a jockey pump for this size fire pump is less than what is available from the city suppy (NFPA 20H recommends a jockey pump of 7.5 gpm @ 60 psi).

For these reasons, I have concluded that a Jockey Pump is not required; is there something that I am missing or any error in my logic?

 

[DubMac]

Your facility's system will now depend upon the City maintaining sufficient water pressure to pressurize your system. Probably fairly safe, but why take a chance for such a small pump?

 

[Artisi]

Agreed, in theory safe, however - your reasoning assumes that the towns pressure will always be above the designed minimum pressure.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[MortenA]

I would leo go without the jockey pump. If the pressure drops below the design minimum it seems unlikely to me that there will be water at all to boost - at least for any significant time to make a difference (what I'm trying to say is that low pressure==disruption of service)

 

[pennpiper]

Denver:
#1. I suggest you have an informal conversation with the Local Fire Marshal about your plan and the reasoning behind it.

#2. Leave space for the Jockey Pump(JP)

#3. Install Valved connections, properly located, sized and type, for the JP suction, JP discharge and the Pressure Sensor Switch.

prognosis: Lead or Lag