LP Gas Leak Detection

Bob J. · Apr 8, 2013

Albanach said:
The manual/instruction sheet of my gas range recommends a leak check by opening/closing the tank valve and then observing whether there is a drop in pressure. As far as I can see, this only addresses the gas tightness in the line from the tank to the solenoid operated safety valve.

Should one not check the rest of the line, by leaving it filled after activating burner, shutting it down without emptying line?

You would leave the solenoid on to test the gas pipe from the tank to stove connection. You would also keep the burner(s) off. Any drop in pressure would indicate a leak. Checking
the stove connection, burner valves & tank connections would be straight forward with soapy water in a spray bottle. There should be no other joints/connections between the source & appliance so after shaking all of the above out, if you have a drop in pressure, replacement of the gas line would be in order.

Bob 04 H260 · Apr 8, 2013

How long should the stove, gas pipes and fittings hold the pressure after the gas is shut off at the tank ?
Bob

Ralph Johnstone · Apr 8, 2013

I would say a 24 hour test (as described by Misfits) without a drop in pressure should tell the story.

HOWEVER don't get toooooooooooo concerned if you see a few pounds drop overnight and you're checking first thing on a cold morning. The gas pressure may change a little with temperature. If you're worried, wait for the outdoor temp. to go up and see what happens.

Doc_holiday · Apr 8, 2013

I hope you don't have pounds of pressure in the line after the regulator.

Ross · Apr 8, 2013

A leak that will get you into trouble will be evident within a few minutes. I turn the gas on to pressurize the system and shut it off, watch the gauge for a few minutes and if there is no drop turn the tank valve on and go from there.

Bob 04 H260 · Apr 9, 2013

From what I have been able to find out the ABYC standard is for the propane gauge to hold the pressure for 4 minutes after the tank valve is closed. If it would hold full pressure for 24 hrs fantastic ! I don't know if that would be possible with the solenoid valve and the packing around the tank valve. Does anyone have a system that holds the pressure for 24 hours ? Ours holds steady for hours but goes down over night. I think a leak that small would be hard to find, it must have a very small quantity of gas in the line and the pressure after the regulator will be very low.
Bob

robertsapp · Apr 9, 2013

I thought the threshold was a noticable drop in pressure within five minutes.

Ross · Apr 9, 2013

How good are your eyes?

Doc_holiday · Apr 10, 2013

At regulated pressure, the volume and pressure in the line is pretty low so a few hours is good. You have to be careful with high pressure against any controls which usually have a max inlet of 1/2 psi or 15 inches of water column. You would not test against the control more than that. If you had a manual valve at the appliance, you could close that and test the lime between that valve back to the tank valve at 2 psi using a kohlman (sp?) gauge. But they are expensive. Frankly soap bubbles will suffice for checking the line but you also need to make sure the control is holding too and you can check that with a lighter at the orifice.

Regardless keeping the tank off when not in use is advised, especially in a low lying confined space.

Bob J. · Apr 11, 2013

Bob 04 H260 said:
How long should the stove, gas pipes and fittings hold the pressure after the gas is shut off at the tank ?
Bob

Typically when gas piping is tested in new construction, it has to hold for 15 minutes.

John R · Apr 11, 2013

I have a propane detector on my boat. What do others think of these systems?

Ross · Apr 11, 2013

Don't bet your life on it!