Sprinklers for diesel pump house

[chaz12]

I have a 1500 gpm diesel fire pump in a dedicated pump house with 300 gal fuel storage. The pump water supply comes from a 250,000 gal storage tank. The tank is filled with a 6" line off the city main which flowed 1900 gal at 72 psi static, 64 psi residual. I am uncertain about parts of the design for the sprinklers needed in the pump house itself.

If there are 2-4 heads in the pump house, would you need a flow switch for fire alarm?

Would you need an inspector's test valve?

Could you supply the sprinklers off the 6" fill line
rather than the 10" discharge off the pump, and would this have any advantages?

Thanks for any input

Chaz

 

[TravisMack]

I would put a flow switch on the sprinklers. I would think a fire in the pump house would be something that I would want to know about as soon as possible.

You can supply the sprinklers from the fill line if you want. There is no real difference doing it before or after the pump as long as you have adequate pressure for the system.

Since you are supplying the pump from the tank, I would probably supply the sprinklers from the city line. That way, if the pump is down, you still have an active sprinkler system in the pump house.

Good luck!

Travis

 

[stookeyfpe]

2006 International Fire Code, section 906.4 requires that the sprinkler system be electrically supervised.

I am not sure what your separation distance is from the pump building to the protected building. Sprinklers may or may not be required depending on your separation distance and the construction type. See NFPA 20, Table 5.12.1.1.2.

And I like Travis's idea. Just be careful because I can see a plumbing inspector requiring a backflow preventer if one is not currently installed on the supply pipe to the atmospheric tank.

 

[LCREP]

NFPA 20 2003 5.12.1.3 requires the building and or room to have sprinkler protection with a diesel fire pump.

From my insurance point of view we would also require the sprinkler system to be monitored. I like the idea off the public water given the water supply u have.

 

[LCREP]

"I have a 1500 gpm diesel fire pump in a dedicated pump house with 300 gal fuel storage. The pump water supply comes from a 250,000 gal storage tank. The tank is filled with a 6" line off the city main which flowed 1900 gal at 72 psi static, 64 psi residual"

Why not a booster pump off the city water supply? OR does the insurance company want a secondary water supply, i.e. the tank and pump??

 

[gouveia]

Some where in NFPA 20 it says that to have a fully sprinklered building, BOTH the pump house and main building must be sprinklered. Sorry don't have the code book handy.

And, I would definitely put a separate flow and inspectors test on the pump house bldg.

 

[TravisMack]

Something else to consider on this. Typically, when you have a tank as the water source, you don't do a bypass around the pump. But, since it sounds like your city line is coming into the pump house to fill the tank, I would run a bypass from the city line around the pump. The pressures you have seem to be of "material value" and could offer some supply to the system if the pump were down.

I had a similar scenario on a large warehouse. The insurance carrier required the pump and tank as the source for the facility. We brought the city line in the pump house to feed the tank as you are doing. We only had about 50 psi static, but I still ran a bypass around the pump off that city line. It would not have provided much pressure for the ESFR sprinklers at 40' in the air, but could be of benefit to the office sprinklers and other low areas in the warehouse. The added cost was relatively insignificant for the bypass. The project was 1.3M sq ft of warehouse, so adding a couple butterfly valves and a check valve was barely noticed in the costs.

Good luck on your project.

 

[LCREP]

I have also asked and get ( from and insurance point of view) a suction point off the tank so the FD can draft from the tank if the pump does not start. Just have to make sure the vent at the top of the tank is the same size as the fire pump and FD pumper. Also the tank has to have a road to the tank so the FD can get to it.

 

[chaz12]

Thanks for the replies, everyone. They were very helpful.

Chaz