NFPA 20 Test Loop

[CPGTECH]

Hi All!

Is there any requirement to provide additional test loop around the fire pump if the system is already equipped with metered test header?

Thanks All!

 

[LCREP]

Is the meter piped back to the suction side of the pump? If yes, then as per NFPA 25 you need to flow water via the test header every 3 years, so you need one. If the meter flow is to a drain or back to the tank, where you can actually flow water, then a meter is OK.

I had a flow meter only back to the suction side of the pump on a $1 billion hospital, the test header was removed as part of an addition 10 years ago. The pump tested was fine for the 10 years via the meter. As the insurance engineer I wanted a test header to flow water as per 25. They did not want to do it because of $$$, local AHJ had no problem with no water flowing. I stuck to my guns, they installed the test header. Witnessed the flow test, 1st hose header valve opens, suction pressure goes to 0psi! The curb box valve was closed in the street to the pump when they added the new addition, they were so happy I was a pain in the butt and stuck to my guns.

 

[cdafd]

Are you talking about a bypass?


4.15.4* Pumps with Bypass.

4.15.4.1 Where the suction supply is of sufficient pressure to be of material value without the pump, the pump shall be installed with a bypass. (See Figure A.4.15.4.)



4.15.4.2 For multistage multiport pumps, a bypass shall be installed between the pump suction and the first outlet port and between sequential outlet ports wherever the bypass can provide pressure that is of material value without the impeller. (See Figure A.4.15.4.)



4.15.4.3 The size of the bypass shall be at least as large as the pipe size required for discharge pipe as specified in Section 4.27.

 

[CPGTECH]

Thanks LCREP for your response!

The meter is not piped back to suction line, it is located before the test header, so the meter flows/discharge to drain.
So a metered test loop piped back to the suction line is not required as long a flow meter will be installed to achieved full flow test?

 

[CPGTECH]

Thanks cdafd for your response!

I'm referring to a flow meter piped back to suction line.

 

[LCREP]

You are correct. Make sure the meter is calibrated as per the mfg of the meter. Also use calibrated gauges during the acceptance test and annual flow test. Will the drain be able to handle 150% Gpm rating of the fire pump say for 30 mins?

 

[CPGTECH]

LCREP,

I will verify if the the drainage system is capable to handle the required required flow.

Thanks for the response, really appreciated it.