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Topic: Propane Tank Inlet Valve (Read 537 times) previous topic - next topic

Propane Tank Inlet Valve

It didn't take long to discover my next problem with my 1999 U270 40foot.  I was having the propane supplier fill up my tank yesterday and was told that even though the tank was just under half full, it would only take 2 gallons of propane.  It didn't even move the gauge needle.  The propane person said it was probably a bad inlet valve.

Anybody else run into this problem?  Is there any possible EASY solution other than to drain the tank and find someone who know how to replace the valve?  Anyone replace the valve themselves?  I can probably take off the old one and put a new valve on, but how do I go about completely draining the propane in the tank?

Re: Propane Tank Inlet Valve

Reply #1 –
I just didn't fill my propane tank but used the propane until the gauge read almost empty. Then I hooked up my fire pit and ran it until no more gas. Then I opened the pipe fitting closest to the fill valve. Changing the fill valve wasn't a big deal. So much so that I don't even remember any difficulty doing it.
I do recall setting up a 20" box fan to aid in dissipating any possible propane fumes that might come out while changing the valve. SAFETY FIRST, you know.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Propane Tank Inlet Valve

Reply #2 –
We had a problem one time when on a trip.  Stopped at a place to fill and nothing would go in. They tried several times.  Disconnected..reconnected...nothing.  We left dreading the rest of our trip without A/C.  Stopped at another place and tried it and they thankfully had no trouble!  All we could think was that the first place had a weak pump or something.  So maybe try somewhere else?

If your valve is bad, do what nitehawk did if possible.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: Propane Tank Inlet Valve

Reply #3 –
If your propane tank has a liquid tap, like some earlier tanks had, propane dealer could empty tank via liquid hose into an empty tank. Not only did a shop do that for us to repair inlet valve, he credited us for the estimated propane gallons drained.

An important item to have is an emergency inlet repair adapter, which will be immediately needed IF after filling, the inlet one-way valve FAILS TO CLOSE. Carry this brass screw-on adapter that has new male threads with a built-in one-way valve. These emergency adapters can be left in place until the inlet valve is repaired.

Propane fillers use on the end of their hose, so they are not stuck with a problem of a tank valve that does not close:

MEC Swivel Fill Check Adapter 1-3/4 Acme Part # ME572

IF tank does not seal back up, one has a big-time dangerous problem. Best to be ready.

Re: Propane Tank Inlet Valve

Reply #4 –
Quote from: TurboXK –
Anybody else run into this problem?  Is there any possible EASY solution other than to drain the tank and find someone who know how to replace the valve?  Anyone replace the valve themselves?  I can probably take off the old one and put a new valve on, but how do I go about completely draining the propane in the tank?

I have my set up with both a high pressure and low pressure port, I mostly use the low pressure port to connect a 40# DOT cylinder for those occasions when we run the built in tank empty.  I too had the problem where the propane guy couldn't fill the tank, so I just used propane until there was no more.  Bought this and a couple of other things:

1 3/4" Acme x 3/4" MPT Propane Fill Valve - propanegear

While I was in there, and working swiftly to minimize outside air from contaminating the tank, I examined the original safety valve and found that the inside end had to be in the tank so I removed the valve and spring and installed my brand new 1 3/4" Acme x 3/4" MPT Propane Fill Valve, what I call a  Prestolite POV valve for some reason lost in my memory.

I bought crow's foot wrenches and did some creative grinding to achieve clearance for tightening.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Propane Tank Inlet Valve

Reply #5 –
Thanks for your ideas, everyone.  I have a plan of action now.  First, I am going to try filling the propane from an alternate provider.  Or two.  If the problem persists, I will use up the rest of my tank as much as possible and then buy a new valve.  The swivel MEC fill check adapter sounds like a good purchase, too.

Thanks again for your help.  I am not planning any long trips away from Austin soon, But I will be up at the Oshkosh Wisconsin Air Show next July, if any of you are going.  Probably at the Elkhart Lake Weathertech Sportscar Challenge then, too.

1999 Foretravel U270
2018 Nissan Truck
2018 BMW motorcycle 1200RT
2010 Ducati motorcycle Hyper motard
1973 Rickman 250 MX
2019 Finnish Spitz
2006 J/29 sailboat (just sold)
Looking for a new used sports car

Re: Propane Tank Inlet Valve

Reply #6 –
I had the same problem you have.  I got a new valve and thought I would need to empty my tank completely to replace.

I ran the tank down to 1/4 or so and thought I would just give it a shot.  Pulled the old valve off, expecting a spewing of propane.  I was surprised that very little gas escaped and was not apparent that any really came out.  I'm sure some escaped but it was not a lot.

If you decide to do as I did.  Make sure you extinguish all open flames, and the gas side of fridge, no Smoking.  Loosen the existing valve to make sure you don't have higher gas pressure.

It took me less than a couple minutes from the time I took off the old and had the new one tightened down.
1998 U320 40'
2005 GMC Yukon
MC# 17609

Re: Propane Tank Inlet Valve

Reply #7 –
Liquid propane is only liquid under pressure.  When you removed the valve on your tank all pressure would have escaped and any liquid propane would have instantly flashed to vapor.  It is likely that your tank was empty in spite of what the gauge may have read.  The other possibility is that there is a check valve built into the tank to prevent the rapid escape of propane in the event that the valve is removed.  I'm not familiar with the tank construction.
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: Propane Tank Inlet Valve

Reply #8 –
Quote from: Geodmann –
Liquid propane is only liquid under pressure.  When you removed the valve on your tank all pressure would have escaped and any liquid propane would have instantly flashed to vapor.  It is likely that your tank was empty in spite of what the gauge may have read.  The other possibility is that there is a check valve built into the tank to prevent the rapid escape of propane in the event that the valve is removed.  I'm not familiar with the tank construction.
First some facts about Propane.  On a standard day the internal pressure of the propane is 145 PSI plus or minus and the liquid propane varies in volume with temperature.  That's why we only fill a propane tank 80% full to leave room for expansion.

IF your fill valve is screwed into a welded bung, that's a clear path into the tank.

If your fill valve is screwed into a square plate held in place with 4 bolts then you have an accessory safety valve.  I had the plunger in this valve break in such a fashion as this valve prevented the flow of liquid propane.  Either way, removing the propane fill valve with any pressure in the tank is a very bad idea.  Opening the 80% "outage valve" a couple of turns will be the final indicator that you've used up all of the propane inside the tank.  And yes, most propane technicians will not be familiar with this additional safety valve.

If you're going to replace the fill valve yourself, have one on hand along with the yellow thread dope or tape and go with your normal routine until all of the propane is gone.  The safety odor will become quite intense near the end as that has been concentrated through the distillation process.  Any doubt?  Hire a technician from the propane company, learn your system, and politely but firmly coach the technician any time you see the "deer in headlights" look in his eyes.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.
 

Re: Propane Tank Inlet Valve

Reply #9 –
On my last coach I had to rebuild all the valves and hoses. (want to do this on the FT too) I was concerned about emptying a large propane tank to atmosphere and I have neighbors so I called the fire dept and gave them a heads up in case someone called for smell of gas. I opened the valve and it took a very long time to drain. Not going to lie I was nervous but I was re-assured by the FD that it really isn't that dangerous  in open air.  Just make sure no open flames or possible sparks generated in the area. I unhooked batteries first!