I put a pressure gauge inline between the tank and regulator for the first time ever.After I shut the gas off the pressure on the gauge will drop overnight from green (pressurized) to the red (meaning low low pressure).Should the pressure on the high side remain high for days/weeks or is it normal for that to drop? Im not sure if the regulator is venting it or if I have a leak after the regulator.Nothing bubbles, but there is one fitting I cannot get to.I used Nylog on every fitting.3/8 copper and flare fittings.There is only a space heater (has solenoid valve) and a stove.I cannot detect any odor.

Might be a very slow leak, but did you take temperatures into consideration?

RV Propane Leak Test.......High Pressure Side (before Regulator) Turn the main LP Gas Valve to the on position and listen for the initial PSST sound. After a second or two, the sound of flowing LP should stop. Next step is to notice the green band in the clear regulator cap. Now turn the main LP gas valve off at the LP tank for 3 to 4 minutes. Watch the green band in the clear regulator window, and it should stay green. If it turns red, (low gas indicator), this indicates a possible leak.Low Pressure Side (after the Regulator) Requires using a manometer connected to system.....stove top burner at manifold can be used Valve in Propane Supply....verify system is 11"WCValve out Propane Supply...then slowly open burner knob and drop system pressure to 8"WC then close burner knobMonitor pressure for 15 minutes....no change in system pressure then system is GOODSystem pressure drops....how fast will indicate size of leak But only 15 minutes is required for leak down test on low pressure sideAnd only 3-4 minutes on high pressure sideDoubt you have a leak....indicator green/red is NOT a accurate means of testing

The LP standard for leak test is as follows.Pressurize to 11 to 14 inches WCInstall the manometerLower the WC to about 8 inches wcMeasure the Manometer for 3 minutesThe system passes if no drop in pressure during the test.There is no such thing as a completely sealed LP system. The system will leak down the LP in the system when the Tank is turned off over days/weeks. YOU NEVER USE OR NEED TO USE ANY SEALANT ON A FLARE FITTING. NEVER!If a flare leaks FIX the copper flare, do not attempt to use sealant. PIPE fittings, you use sealant/teflon tape. Doug

So, it is not normal for the pressure to leak down overnight?This is not a red/green indicator as on a two-tank system, it is a dial, green range is full tank, as tank pressure lowers the dial moves into a red colored background (not unlike the red in your rpm tachometer).The dial measures psi and shows this with a needle.I should have explained this more clearly at first.Nylog is the stuff. It is cheap insurance for sealing things. It is used in the refrigeration industry as gospel. Use it on all your propane fittings from now on. Teflon tapes are of the past now unless you need to lubricate the threads..I did not use Nylog on the tank fitting, possible that is a leak? I will go bubble check that and nylong it and retest.**also, this tank I have had sitting in garage for 6+ months so I do not suspect it is leaking when closed.Temps change very little overnight here during summer, not enough to swing psi this much.If this is not normal then I will assume it is the pigtail, which is the only used part in the system other than the heater.

Old-Biscuit wrote:RV Propane Leak Test.......High Pressure Side (before Regulator) Turn the main LP Gas Valve to the on position and listen for the initial PSST sound. After a second or two, the sound of flowing LP should stop. Next step is to notice the green band in the clear regulator cap. Now turn the main LP gas valve off at the LP tank for 3 to 4 minutes. Watch the green band in the clear regulator window, and it should stay green. If it turns red, (low gas indicator), this indicates a possible leak.Low Pressure Side (after the Regulator) Requires using a manometer connected to system.....stove top burner at manifold can be used Valve in Propane Supply....verify system is 11"WCValve out Propane Supply...then slowly open burner knob and drop system pressure to 8"WC then close burner knobMonitor pressure for 15 minutes....no change in system pressure then system is GOODSystem pressure drops....how fast will indicate size of leak But only 15 minutes is required for leak down test on low pressure sideAnd only 3-4 minutes on high pressure sideDoubt you have a leak....indicator green/red is NOT a accurate means of testingThis is why I have a shutoff c0ck valve behind every propane appliance. My Manchester motor fuel 83 gallon tank has a high flow block off that stops the flow 100% and stays 100% shut off.

Propane leakdown | Good Sam Community

dougrainer
Nomad
Sep 04, 2020
The LP standard for leak test is as follows.

Pressurize to 11 to 14 inches WC
Install the manometer
Lower the WC to about 8 inches wc
Measure the Manometer for 3 minutes
The system passes if no drop in pressure during the test.

There is no such thing as a completely sealed LP system. The system will leak down the LP in the system when the Tank is turned off over days/weeks.
YOU NEVER USE OR NEED TO USE ANY SEALANT ON A FLARE FITTING. NEVER!
If a flare leaks FIX the copper flare, do not attempt to use sealant. PIPE fittings, you use sealant/teflon tape. Doug
Old-Biscuit
Explorer III
Sep 04, 2020
RV Propane Leak Test.......

High Pressure Side (before Regulator)
Turn the main LP Gas Valve to the on position and listen for the initial PSST sound. After a second or two, the sound of flowing LP should stop.
Next step is to notice the green band in the clear regulator cap. Now turn the main LP gas valve off at the LP tank for
3 to 4 minutes.
Watch the green band in the clear regulator window, and it should stay green. If it turns red, (low gas indicator), this indicates a possible leak.

Low Pressure Side (after the Regulator)
Requires using a manometer connected to system.....stove top burner at manifold can be used
Valve in Propane Supply....verify system is 11"WC
Valve out Propane Supply...then slowly open burner knob and drop system pressure to 8"WC then close burner knob
Monitor pressure for 15 minutes....no change in system pressure then system is GOOD

System pressure drops....how fast will indicate size of leak
But only 15 minutes is required for leak down test on low pressure side
And only 3-4 minutes on high pressure side

Doubt you have a leak....indicator green/red is NOT a accurate means of testing
Lynnmor
Explorer
Sep 04, 2020
Might be a very slow leak, but did you take temperatures into consideration?

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