Firefighting Pump Sets - Sequence of Operation

[Buildtech2]

Our client is willing to have two firefighting pump sets on the site. One set will serving to all buildings for sprinklers and fire hose cabinets while the other set is dedicated for only external fire hydrants on the yard.Is it required to interlock these pump sets sets so that both will operate at the same time in the event of fire in any building or on the open yard. Please advise.

 

[MatthewJWillis]

I do not think so as the first pup is required to be sized INCLUDING hose streams for the sprinklers system. I think you are dealing with 2 different books here. Well 3, including NFPA 20, 13,
and IFC for the yard system.

R/
Matt

 

[mk3223]

The question for the single pump system is that, if the pump was down, there is no firewater backup. The NFPA code may require the design to have a backup system.

 

[Buildtech2]

At both the locations, we have firefighting pump set, it means there are 3 pumps, electric, diesel, and jockey pumps.

 

[LCREP]

Are you sure the hydrants and sprinkler system are separate water mains, sounds very expensive to have to separate water supplies for each system. Is this project in the USA?

 

[Buildtech2]

I am aware that it would be very expensive to have seperate water mains for both hydrants and sprinkler system which we normally never design like this but our client is insisting to seperate both water mains with seperate pump sets without any valid technical justification. This project is in Dubai.

 

[LCREP]

The only time NFPA 20 offers guidance is when 2 pumps service the same system. They recommend a 5 psi start pressure difference between the 2 pumps. I am not aware of any NFPA code requirements for your situation. Have you reached out to the insurance carrier engineering department for guidance?

 

[mk3223]

Looks to me that the owner wants two separated pumps sets for its facility as long as each set can provide adequate protection per local Authority.

Are two systems required to be operated at the same time? Anyway, you may propose an interlock function to improve the operation flexibility, so they can be activated either one or two together.

 

[rajm008]

Some people in UAE uses fire system for other uses like watering plants or cleaning their sheds etc. So that might be reason for them to go for two diff pump set. I cant see any other reason as to why . both UL pumps means really high price.should ask client itself. Anyway the drawings whould be approved by local civil defense. For foam systems sometimes they ask for diff pump set.