Acceptable Propane Leakdown?

[Rustysocket]

I have a 2017 fifth wheel with dual propane bottles and I was wondering what the rest of you have experienced in regards to the propane system.

I have noticed that if I have the bottles turned off, that after about 36 hours the gas that is in the lines between the bottles and the rest of the system has bled off.

I determined this by watching the indicator flag on the auto switch over regulator over a period of time and monitoring when it goes from clear to red.

I first pressurize the lines and make sure the appliances are all off. I then close the bottles and monitor the regulator every few hours until it shows that the pressure has bled off.

In my mind this system should not bleed off at all, but then when I read what the standard is for the test it is only required to hold pressure for a very short time.

I do not ever smell propane.

I was wondering if one of you with some spare time could try to duplicate and see how long your rigs hold pressure on a closed system.

[Hoppy220]

Took me awhile, and I still can't give you really good numbers, but I can tell you mine lasted more than 4 but less than 24 hours, if you got 36, id think that's pretty good, I'm about to start the leak hunting process

[dewey02]

I think this is perfectly normal, although I cannot explain where the propane goes.
All I know is that whenever I have the propane turned off for an extended period, I always have to turn on the gas burners and let them vent air for about 30 seconds to a minute before they will light. This has happened with every trailer I've owned (3) and I think it happens to everyone else who owns one.

I think that the propane in the lines goes to the exact same place that all those socks go when you put them in the wash and always end up with an odd sock!

[North of 49°]

Originally Posted by dewey02

I think that the propane in the lines goes to the exact same place that all those socks go when you put them in the wash and always end up with an odd sock!

The current theory is that the spin cycle opens up an extra dimensional vortex that sucks socks in at random, and spits them out somewhere on the other side of the universe. So there's a planet somewhere that's chest deep in socks -- and none of them match.

Oh yeah, and they all smell like propane.

[Rustysocket]

Thanks for the replys.

While I have been told by many that this is normal and that their rigs do the exact same thing, I am struggling with the concept of where the pressure goes.

I have yet to hear from anyone who says their rig will hold this pressure continuously.

[Mopar_Earl]

Unfortunately no LP system will hold pressure long. It will change with tempature and no system is 100% leak proof. The rule is if it holds 8" of WC for at least three minutes it's good.

The RV Doctor: What the Pro's Do - Propane System

The RV dealers perform the tests in the above link.


Earl

[Rustysocket]

Originally Posted by Mopar_Earl

Unfortunately no LP system will hold pressure long. It will change with tempature and no system is 100% leak proof. The rule is if it holds 8" of WC for at least three minutes it's good.

The RV Doctor: What the Pro's Do - Propane System

The RV dealers perform the tests in the above link.


Earl

Earl,

Prior to starting this thread I had come across the testing procedure and while I have not connected a manometer up to a stove burner and actually performed the test I'm confident my system would pass at this point. There is a provision in the test that states that the system would initially hold 11" and then be bled down to 8" prior to taking the measurement to prevent regulator lockout (or something along those lines).

Coming from my background as a analytical chemist who has installed, pressure tested, and leak checked dozens of gas chromatograph installations I am struggling with the "why" the system leaks down.

Is it the fittings? Is it the appliance valves? is the line itself permeable to the gas over time (like a baloon deflates)?

My primary concern is that I have a proper operataing system that is safe... and it appears that I do.... from that point it is simply my curiosity getting the best of me...

On to bigger projects now.... One of the kids decided a pantry door would make a nice swing and split it at the hinges... so off to the store to get some bar clamps and wood glue.

Thanks for your replies.

[estesbubba]

With my Jayco and previous 2 RV's I would have to prime the lines before each trip using the stove otherwise my fridge might not run using propane. The stove would always take a few to light and sputter for a few until the propane was flowing cleanly.