Fire Pumps to reduce pipe size 1

[RoyalFire]

I received a call from a local developer with a question that I haven't come across. He wants to use jockey pumps on each floor of a 7 story building to reduced pipe sizes. The system apparently works without a pump but has larger piping and he is convinced that the 7 jockey pumps are a good idea. There is plenty of water, and pressure currently.

Pros, smaller pipe sizes.

Cons, less reliability in equipment, however, if water supply degrades it could supplement the needed water.
Regulated additional equpment such as bypass, relief valves, etc would possibly offset the savings in pipe size, including increasing the stair to have a room that would fit the equipment.

I don't see anything in 20 which says you cannot, but it just doesn't seem to be a good idea. Any thoughts?

 

[SprinklerDesigner2]

Jockey pumps are not rated so they can not be used.

 

[MGXFP]

Fire pumps must be listed if you want to use them for fire protection. A jockey pump is not listed as a fire pump. This arrangement does not comply with NFPA 20.

I have a couple questions:
1. How does a jockey pump reduce pipe sizes? Typically jockey pumps flow 5-20 gpm. A single 1/2" sprinkler at 7 psi discharges about 15 gpm. A jockey pump is designed to be overwhelmed by 1 sprinkler.
2. A jockey pump can't meet the hydraulic demand of a remote area. How does a jockey pump meet the demand?

Does the AHJ approve of this arrangement?

 

[LittleInch]

I suspect what your developer actually means is that he thinks 7 FIRE OUMPS will somehow offset their cost by using smaller pipes. He just knows jockey pumps are smaller so used that terminology.

But the devil is in the detail and frankly sounds bonkers.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TravisMack]

This is what happens when a person knows enough to be dangerous but not know enough at all. The system is an NFPA 13 system. NFPA 13 references NFPA 20. NFPA 20 will require a listed fire pump. The jockey pump alone will not suffice. Why not just one properly sized fire pump to reduce pipe sizes? It seems crazy that you could offset the material enough to justify the initial and ongoing costs for a fire pump, but someone would have to run the numbers.

Travis Mack, SET, RME-G,
MEPCad, Inc
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