ips gas test

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