Propane System Pressure and Leak Down testing

[GCroyle]

Folks,

I was intrigued by Darren’s My RV Works video on testing your propane system so I made my own test rig. I chose to remove the WH burner to make attaching the test rig easier. The locked PSI and loaded testing went well but the leak down, not so good.



During the leak down test, I could watch the pressure slowly drop, now time to find the leak. I soap bubbled from the tanks, regulator, hose, copper line and all fittings including the stove.

No bubbles found and I had no know propane leak symptoms.

Next, I decided to disconnect each appliance service line and plug the line. Re-pressurize and leak down test for each of them. Stove and refrigerator, no change and the WH burner was already disconnected. That left the furnace.

I’ve had the furnace burner out for service, not difficult to do. Then I capped the furnace line and leak tested. No more leak down pressure loss.

Next, I attached the burner and valve to my test line and turned on the propane. With soapy water on my finger tip the burner orifice blew bubbles. Order new valve, transfer the old parts to new valve, install and test. The leak down test was easily passed with the new valve.

If you’ve never had your rigs propane system leak down tested, might want to consider it as a maintenance item.

Please be careful if you decide to try working on your own propane system might be time to have your shop do this test.

Gary

 

[Wiredawg]

Great writeup. thanks.

Cheers, Ron

 

[promisedland]

Good job, I'm in the l.p. industry and it's amazing how little "some" folks understand/care about their systems.
Always blows my mind how some red-necks will leak test with a lighter..
Slapping a gauge on the line and turning the supply off is the best, soap is a great tool to find the leaks.
This is my ride the last 5yrs.

 

[promisedland]

Wrong pic, this is my ride.

 

[GCroyle]

Promisedland,

Thanks. My goal was not a tutorial on how to do it rather just raise a little awareness about it.

After initial testing I verified a Marsh inches of water gauge to the U tube changed to Marsh and now it’s a portable tool.

Gary

 

[Tuesdak]

LP related maintenance items are the electronic LP leak detector in the RV as it has a 5 year lifetime. The CO detector is also a limited life item of 5-7 years. Smoke alarm is 10 year life. Replace them if they are over this age. The date of manufacture should be on the back of the alarm if in doubt to it's age. (New ones have a "lifetime's up" alarm in them - older ones do not.)

It doesn't hurt to "leave it to the professionals" like @promisedland for your RV. Most propane outfits can leak check your RV system including a tech doing a house call.

I had a leaking hose off a tank I could not find with soap bubbles but could smell. So I had the local propane outfit adjust the twin tank Rego regulator after finding and fixing the leak.

I grow tired of the troublesome non-adjustable China regulators starving the generator for fuel when they fail and got a USA made Rego unit. Your propane supplier can get the Rego stuff as it's not at the local RV shop/store. (The propane outfit reached for the Cheap China stuff till I made them order a Rego in.) The Rego on my RV been working fine since 2016. You can also get Made In USA Teeco hoses for the tanks as well.

https://www.regoproducts.com/lpg/lpg-nh3-products/products/7525b.html

A new product just out is an ultrasonic fuel gauge for propane tanks. About time something with some accuracy came out for the 20-100LB tanks without built in gauges.

https://www.mopeka.com/

Another maintenance item: these tanks (pictured) need to be re-certified after 12 years and then every 5 years. Shop around as some places require a new valve ~$50 and it's almost cheaper to go new esp. for 12 year vs. 5 year cert life. (One valve on my tank was leaking when turning on/off so it's not just a cash grab.)

USA Hose brand.

 

[promisedland]

2x on Rego

 

[mwilson]

I bought a new 30 for my fifth wheel after finding out a recert cost darn near as much a new a few years ago. Probably not the case now....

One thing that concerns me is the new tank requires about 3 full revolutions of the hand wheel to shut it off. OEM tanks were less than a full turn.

Is there a specific valve for RV's that shut off quickly? I picture myself turning the hand wheel like forever while flames are jumping at me....

 

[promisedland]

Haha! It would seem like forever!
I have very little to do with RVs, once in a while a customer asks me to top off his tank when I'm at his home filling a big tank for the house.
What I remember is they have the reg 3ish turn valve.....

 

[Tuesdak]

OEM tanks were less than a full turn.

You got DOT tanks on it or the standard 20/30/40 LB tanks? Like the pic above on mine is a 40 LB tank and it takes a few turns on the valve between off/on.