NFPA 20 Questions

[Ub1que]

Hello Everyone,

This is my first post on the forum. I'm hoping you guys can help me out with a few questions about fire sprinkler systems, particularly, regarding NFPA 20 code. I'm currently developing a Diesel driven, split horizontal pump @ 1000 gpm.

1. Hose Valves and Fire Department connection - From what I understanding of the NFPA 20 both a hose valves + header ( For testing the water supply ) and fire department connections are required by all fire sprinkler systems. I have seen a lot of fire pump packages (ie; AC fire pumps) where neither a hose valve header or fire department connection are included. Are these items required on all systems, or are there circumstances where they can be ommited?

2. Tees and elbows located on the suction line - I would like to have a test loop on my system. therefore, the pipe tees would be vertical, or would have a centerline plane perpendicular to my drive shaft. Section 4.14.6.3.3 says " Elbows and tees with a centerline plane perpendicular to the horizontal split case pump shaft shall be permited at ANY LOCATION in the pump suction intake. Now, after reading through section A.4.20.1.2 (2) it says " There should be a distance of not less than 5 diameters of suction pipe for top or bottom suction connection to the fire pump suction flange". I'm confused as these two sections seem to contradict one another. I have again seen systems by AC fire pumps and other manufacturers where the intake tee for the test look is connected directly to the pump intake. Can anyone clarify how, or why this is acceptable given the A.4.20.1.2.

Thanks a lot!

 

[LCREP]

1. A FDC is always required for most instances. NFPA 13 has a few exceptions when the FDC is not required, one of them being if the sprinkler demand is greater than what the FD can deliver say a airplane hanger with a flow of 15,000 GPM. Check it out to see if they apply, most times you will need to provide a FDC.

A pump test header is always required unless you use a flow meter to an open discharge such as a tank or open drain etc. If the meter flows back to the suction side of the pump without flowing water, NFPA 25 requires water to be flowed every 3 years. So you will need a test header.

2.The section you refer to is on the suction side of the pump, where water enters the pump. After the pump discharge you can have as many elbows you want as long as it works hydraulicly.

 

[cdafd]

So are you just trying to sell an engine and pump package????


If so than all the extras are supplied by whoever installs the rest of the pump
Room setup

 

[Ub1que]

Thanks LCREP. I will have to check through NFPA 13 to verify if a fire department connection is required. The fire sprinkler system is for a construction camp, so I believe there would be fire department connection located around the building.

 

[Ub1que]

One more question if you don't mind LCREP. If I were to pipe my testing line ( with flow meter connected ) back to my supply tanks, I could eliminate the hose valves + header?

 

[LCREP]

Regarding the FDC from NFPA 13, 2013 Ed

8.17.2.2 The following systems shall not require a fire department connection:
(1) Buildings located in remote areas that are inaccessible for fire department support
(2) Large-capacity deluge systems exceeding the pumping capacity of the fire department
(3) Single-story buildings not exceeding 2000 ft (186 m ) in area

Regarding the pump test header.

Yes if the flow meter goes back to the tank no test header is required as per NFPA 20 and 25.