Hydrostatic Test with air

[mzg123]

can anyone tell me that if it is acceptable to do hydrostatic test only with air after modification to sprinkler system. since the existing facility is a data centre, it is risky to do hydrostatic test with water.

Thanks

 

[cdafd]

1. is this a wet system or pre action???



NOOOOOOOOO


24.2 Acceptance Requirements.
24.2.1* Hydrostatic Tests.
24.2.1.1 Unless permitted by 24.2.1.2 through 24.2.1.6, 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.
24.2.1.2 Portions of systems normally subjected to system working pressures in excess of 150 psi (10.4 bar) shall be tested as described in 24.2.1.1, at a pressure of 50 psi (3.5 bar) in excess of system working pressure.
24.2.1.3 Where cold weather will not permit testing with water, an interim air test shall be permitted to be conducted as described in 24.2.2. This provision shall not remove or replace the requirement for conducting the hydrostatic test as described in 24.2.1.1.
24.2.1.4 Modifications affecting 20 or fewer sprinklers shall not require testing in excess of system working pressure.
24.2.1.5 Where addition or 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.
24.2.1.6 Modifications that cannot be isolated, such as relocated drops, shall not require testing in excess of system working pressure.
24.2.1.7 Loss shall be determined by a drop in gauge pressure or visual leakage.
24.2.1.8 The test pressure shall be read from a gauge located at the low elevation point of the system or portion being tested.

 

[mzg123]

Thanks for reply,

It is pre-Action system.

24.2.2.1 In addition to the standard hydrostatic test, an air pressure leakage test at 40 psi (2.8 bar) shall be conducted for 24 hours. Any leakage that results in a loss of pressure in excess of 1½ psi (0.1 bar) for the 24 hours shall be corrected.

 

[NJ1]

First of all a hydrostatic test with air does not exist. Hydro comes from water. You meant to say a prressure test with air instead of water.
My answer is no. The NFPA calls for that particular task a Hydrotest however if exposed during cold weather conditions you might be allowed to do air test as per AHJ's

 

[spkreng]

start before you dig, hopefully your installation crew did a "blow back" which means everything is relatively connected, next by all means pump it up with air, at 40 psi and if you have any loss of 1.5 psi or greater over 24 hrs investigate with a soapy sponge, then you are ready for a NFPA #13 200 psi Hydrostatic test

spkreng, CET

 

[mzg123]

Found this in NFPA 13-2007:

24.2 Acceptance Requirements.
24.2.1* Hydrostatic Tests.
...........

A.24.2.1 The use of noncombustible compressed gas to increase the pressure in a water-filled system is an acceptable test
procedure.

 

[786392]

Probably this further emphasizes the Water fullness of any under test system;I believe.

However it in a way permits use of non-combustible to supplement alone,others may correct/guide.

Best Regards
Qalander(Chem)