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Finding leaks the hard way

Big Will
Big Will Member Posts: 396
We have a project with four pipe air handlers throughout the building. One of the four lines has multiple leaks we separated the line into three large sections. Each section is leaking about 2 psi a day. The system is very large. Three Knight 499s feed it. We have been messing with this for about two weeks trying to find the leaks. We are running out of time so so I am looking for a magic cure. We have been runing a 200 psi test and using bubbles at all the joints. Other than that the only option is the hydrostatic test pump. This causes problems with fixing the leak when we find it. This may be the answer at this point though. We are brazing all the lines so we can make a pin hole to drain the water and braze it closed. Any other input would be helpfull although I think this is a shot in the dark.  Thanks.


  • hot_rod
    hot_rod Member Posts: 22,266
    are you sure

    you have a leak? 2 psi in a large system, with high test pressure? Temperature change causes pressure to change. Does it go to zero ever?

    Water, or high tech options are about it.

    Leakbusters.com finds steam leaks on military ships, among other things. I've used them to find multiple leaks in slabs. They sometimes use inert gas and a sniffer. Or circulate water with air entrained and use listening devices.

    But, water under pressure generally shows the pinholes quickly.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669

    put some propane in it and use a gas leak detector.

    works every time.
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,338

    Hello:  I've had very good luck using an ultrasonic leak detector with air in the lines.  Works nicely for small leaks.

    Yours,  Larry
This discussion has been closed.