How to air pressure test water pipes

[max2016]

Hi Guys

UFH water pipes Im looking to Air pressure test the pipes before 2nd fix

What equipment do you guys use for air pressure testing of water pipes

Thank you

 

[Madrab]

You need to be very careful if air testing pipework, it can cause significant damage if a fitting or pipe goes due to the ability of air to be compressed.

It isn't standard practice to use air to test water systems, would always recommend wet testing. 1.5 times the working pressure for 90mins after stabilisation.

 

[justigator]

On my rare forays into plumbing, I try to make up - usually by soldering - what I can best call sub-assemblies: sets of pipework having a number of joints, that are small enough overall to be tested for leakage in my car boot. Why? Because there I can join them with demountable pushfits onto another bit of pipework that has a pressure gauge attached, one with a valve that accepts a feed from a standard 12 volt tyre pump. All open ends sealed, of course. With pushfits, all of them arranged and if necessary covered such that if one should blow off on testing with compressed air, there will be no risk of injury. Some sub-assemblies have been small enough to immerse in a bucket of water where a leak will be immediately apparent; with bigger ones I have just ramped the pressure up to 3 or 4 bar or so and left them some minutes to slowly leak and release pressure (or hopefully not), as shown on the gauge. If a sub-assembly is leak-free, then I will typically only have one joint or maybe two to pay attention to when installing it in the house. Wet testing obviously better - if possible and economic.

If I could pump compressed air in the house, maybe with a 12 volt car battery, then I could test more thoroughly.

 

[endecotp]

Cheap but good-enough water pressure testers like the one in the photo in Madrab's post are available on eBay for under £15.

Don't mess around with compressed air.