Fire service main testing 1

[N3M4N]

Hi all,

When pressure testing the water meter assembly the actual meter itself is left out, is there a reason why the meter is left out? is there specification or code reference that speaks to this? Once the meter is put back in there will be two new joints that won't be accounted for.

Is the fire service main designed under the same code as the domestic water mains? Where can I find testing standards for fire main? is it in the NFPA?

Should the Fire service main also undergo swabbing, chlorination similar to the domestic water main?

What pressure should the fire service main be tested at (200 psi for 2 hours?) what is the allowable leakage?

Thank you in advance.

 

[amlinerrichard]

Standard test for pressure lines is 2 times the working pressure plus 50 psi. Leakage is less than 20 gal per internal inch diameter per day

 

[coloeng]

From the 2016 Edition of NFPA 13

10.10.2.2.1* All piping and attached appurtenances subjected to system working pressure shall be hydrostatically tested at gauge pressure of 200 psi (13.8 bar) or 50 psi (3.4 bar) in excess of the system working pressure, whichever is greater, and shall maintain that pressure at gauge pressure of ±5 psi (0.34 bar) for 2 hours.
10.10.2.2.2 Acceptable test results shall be determined by indication of either a pressure loss less than gauge pressure of 5 psi or by no visual leakage.

25.2.1.1 Unless permitted by 25.2.1.2 through 25.2.1.5, all piping and attached appurtenances subjected to system working pressure shall be hydrostatically tested at 200 psi (13.8 bar) and shall maintain that pressure without loss for 2 hours.
25.2.1.2 Portions of systems normally subjected to system working pressures in excess of 150 psi (10.3 bar) shall be tested as described in 25.2.1.1, at a pressure of 50 psi (3.4 bar) in excess of system working pressure.
25.2.1.4 Modifications to existing piping systems shall require testing at system working pressure.
25.2.1.4.1 Where modification is made to an existing system affecting more than 20 sprinklers, the new portion shall be isolated and tested at not less than 200 psi (13.8 bar) for 2 hours.
25.2.1.4.2 Modifications that cannot be isolated, such as relocated drops, shall require testing at system working pressure.
25.2.1.5* The test pressure shall be read from a gauge located at the low elevation point of the system or portion being tested. The pressures in piping at higher elevations shall be permitted to be less than 200 psi (13.8 bar) when accounting for elevation losses. Systems or portions of systems that can be isolated shall be permitted to be tested separately.

From the 2017 Edition of NFPA 25

6.3.2.1* Hydrostatic tests of not less than 200 psi (13.8 bar) pressure for 2 hours, or at 50 psi (3.4 bar) in excess of the maximum pressure, where maximum pressure is in excess of 150 psi (10.3 bar), shall be conducted every 5 years on manual standpipe systems and semiautomatic dry standpipe systems, including piping in their department connection.
6.3.2.1.1 Manual wet standpipes that are part of a combined sprinkler/standpipe system shall not be required to be tested in accordance with 6.3.2.1

 

[LittleInch]

What's the design pressure of the meter? Will it withstand the test pressure without damage?

Test pressure is there to test mechanical strength not leaks from flanges.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Krystal Hale]

I need a little more detail. And then you can get good advice.