NFPA #20 Figure A-2-14.1.2(b) Flow Meters

[SprinklerDesigner2]

From NFPA #20 A-2-14.1.2

Figure A-2-14.1.2(b) Typical arrangement for measuring fire pump water flow with meter. Discharge from the flowmeter is recirculated to the fire pump suction line.

http://img170.imageshack.us/img170/6518/pumpff1.jpg

The diagram references note #4.

(4) The fire protection system should have outlets available to test the fire pump and suction supply piping. (See A-2-14.3.1.)

There's a world of difference between should and shall so I am not going to do it but I must be dense today because I can't figure what they want.

 

[cdafd]

Remeber you are in the "A" section so it further does not apply along with the "Should"

 

[LCREP]

How will you conduct the acceptance test on the fire pump without a test header to flow water? Also NFPA 25 requires water flowed every 3 years if you have a meter. If the meter is piped to the suction side of the fire pump, you will not know if any valves are shut.



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Fire Sprinklers Save Firefighters’ Lives Too!

 

[TravisMack]

I am sure that NFPA 20 references NFPA 25 for maintenance. Therefore, as LCREP stated, you will have to have a way to comply with the NFPA 25 requirement to flow water every 3 years. Therefore, I think you are req'd to put the test header in regardless. You can use a flow meter if you want.

Travis Mack
MFP Design, LLC

 

[SprinklerDesigner2]

Of course the system will have a test header as shown on the diagram. My question had to do with note #4 located top left of diagram. The pump test header is on top right.

 

[cdafd]

from nfpa 20 2003



A.5.19.3.1 The hose valves should be attached to a header or manifold and connected by suitable piping to the pump discharge piping. The connection point should be between the discharge check valve and the discharge gate valve. Hose valves should be located to avoid any possible water damage to the pump driver or controller, and they should be outside the pump room or pump house.

If there are other adequate pump testing facilities, the hose valve header can be omitted when its main function is to provide a method of pump and suction supply testing.

Where the hose header also serves as the equivalent of a yard hydrant, this omission should not reduce the number of hose valves to less than two.

 

[cdafd]

nfpa 20 2003



A.5.19.1.1 The two objectives of running a pump test are to make sure that the pump itself is still functioning properly and to make sure that the water supply can still deliver the correct amount of water to the pump at the correct pressure. Some arrangements of test equipment do not permit the water supply to be tested. Every fire pump installation needs to have at least one arrangement of test equipment where the water supply can be tested. Inspection, testing, and maintenance standards (NFPA 25) require the pump test to be run at least once every three years using a method that tests the water supply's ability to provide water to the pump.

 

[SprinklerDesigner2]

Still having to do with Note 4. Maybe this will clarify my question.

http://img359.imageshack.us/img359/2258/hoseheaderem3.jpg

 

[cdafd]

appears you meet the standard.

remember you are reading from the appendix,

 

[SprinklerDesigner2]

Ncdafd,

Yes, but I would still like to know why Note #4 is there to begin with. As far as testing the suction line you can do that through the hose header.

The true answer is probably lost to antiquity seeing how the figure drawing probably first appeared in the 1914 edtion.

 

[cdafd]

because it costs to remove it

and once again it does say "should" like you say it more than likely has been there for a number of years.
it is in 1999 nfpa 20


it does refer you to:


A.5.19.3.1 The hose valves should be attached to a header or manifold and connected by suitable piping to the pump discharge piping. The connection point should be between the discharge check valve and the discharge gate valve. Hose valves should be located to avoid any possible water damage to the pump driver or controller, and they should be outside the pump room or pump house. If there are other adequate pump testing facilities, the hose valve header can be omitted when its main function is to provide a method of pump and suction supply testing. Where the hose header also serves as the equivalent of a yard hydrant, this omission should not reduce the number of hose valves to less than two.

 

[DavidCR]

I have wondered about it also, I think that the "should" may go also for the possibility of AHJ to allow the discharge of the flow meter to be directed back to the suction tank for big pumps where there is a circumstance where a big flow in a test header is dangerous or not possible to measure easily, so you have the possibility of testing every 3 years with real flow and not messing with the water and saving it if it´s expensive.

 

[cdafd]

3.2.5 Should. Indicates a recommendation or that which is advised but not required.