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    ips gas test (3 Posts)

  • bob young bob young @ 9:23 PM
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    ips gas test

    any new techniques on testing gas malleable  fittings other than soap bubbles. any one ever try black swan leak detector ? if so is it worthwhile or are results similiar. for a working pressure of 1/2 "  , what is recommended test pressure is test pressure is 3 # . if you pumped line to say 30 #  would it affect the integrity of the existing threaded joints. bob nyc lic. plbr.
  • Bob Harper Bob Harper @ 7:39 PM
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    gas pressure testing

    The IRC calls for testing at min. 1.5 times the max. working pressure but no less than 3 psig. So, if your max. is 1/2 psi, you test at 3 psi x 10 min. The test gauge must be no greater than 5 times the test pressure. If you test at 3 psi but use a gauge that reads to 30 psi, that would be illegal. If you test at 30 psi your gauge may not read higher than 150 psi. Now, let's say you have a tiny gas leak. Which do you think will show the leak: the 15 psi gauge at 3 psi or a 150 psi gauge at 30psi? Remember, you are looking for any movement in the needle. Parallax error alone can fool you in reading a minor deflection or not. You want the lowest gauge you can so that the slightest movement of the needle will indicate a leak. All this high pressure testing is asinine. Yes, some fittings can be compromised by higher pressures. For instance, some shutoffs are rated for only 3 or 5 psi. Now, they may have been tested to 125psi burst but that does not mean the can't leak. I can assure you that those brass "key' valves located in the floor or wall for gas logs in fireplaces WILL leak if tested >3psi except for the newer ball valve types.

    When selecting a soap bubble test solution, look for one that is non-corrosive. Otherwise, you definitely have to rise it off. Otherwise, you can cause stress cracking in the base metal and cause a leak later. For very tiny leaks, try a thin-film solution. Larger leaks will blow these bubbles away so you may need a higher viscosity solution to demonstrate these leaks. That means at least two types of solutions. Also, the colder it gets the thicker they all get. Allow sufficient time for a bubble to form.

    Trace gas leakage can be demonstrated by a "Bubble-O-Meter" such as used in lab testing. You can use a simple manometer to test if an appliance valve or MP regulator is holding or creeping.

    HTH
  • bob young bob young @ 9:50 PM
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    ips gas test

    THANX, BOB.  Needed another opinion from a fresh pair of eyes. yours was probably as good as it gets. very well thought out & precise. thanks again. bob young
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