Fixing a Leaking Propane Fill Valve on a Mounted RV Tank

[wesellyourstuff]

Filled tank with propane and the fill valve spews propane eventually leaking all out. Has this happened to anyone else and what was the solution.

 

[Lou Schneider]

Filled tank with propane and the fill valve spews propane eventually leaking all out. Has this happened to anyone else and what was the solution.

Welcome to The RV Forum! The easiest fix is to replace the whole valve assembly. This should be done by a professional as the tank will have to be purged of air after it's been opened. Any major distributor that services fixed tanks like Amerigas or Suburban can do the work on their lot.

 

[wesellyourstuff]

It is the RV's original propane tank.

 

[Rene T]

Is it a portable tank like a 20# or 30# or is it mounted permanently to the rv?
How old is this tank?

 

[uchu]

It is the RV's original propane tank.

As @Lou Schneider indicated, the leakage is most likely due to a failing filling valve, and it has to be replaced.

 

[PancakeBill]

Important fact for answer, Is it a mounted tank like in a class A or C or a 20 or 30# tank on a trailer? If mounted, taking to an LP distributor to replace valve, if 20, an exchange at a Rhino place, if 30, toos up between cost of repair or new tank.

 

[Gary RV_Wizard]

Need more info to give a meaningful answer. First is whether it is a DOT portable bottle or a fixed (ASME) tank. If it's a fixed ASME tank, definitely need to know where the leak is coming from. If a portable DOT bottle, need to know whether the lead is in the tank itself or at the connection to the external LP regulator & hose. A photo with an arrow pointing to the leak point would be great.

 

[RayIN]

Filled tank with propane and the fill valve spews propane eventually leaking all out. Has this happened to anyone else and what was the solution.

Describe your container please, ASME or USDOT and size.

 

[wesellyourstuff]

Need more info to give a meaningful answer. First is whether it is a DOT portable bottle or a fixed (ASME) tank. If it's a fixed ASME tank, definitely need to know where the leak is coming from. If a portable DOT bottle, need to know whether the lead is in the tank itself or at the connection to the external LP regulator & hose. A photo with an arrow pointing to the leak point would be great.

It is the mounted tank in a Class A RV.

 

[PancakeBill]

OK, that is helpful. If it is not empty spray some gas leak detector arould all the fittings. Because it is a whole system it could really be anywhere, there are fittings in many places. Sart with the valve and connections at the tank.

 

[Larry N.]

If it is not empty spray some gas leak detector arould all the fittings.

Soapy water works...

 

[Gary RV_Wizard]

A fixed ASME LP tank has a filler port that is separate from the service valve (dispensing port). Also a small bleeder valve. Those are the three common sources of leaks and may be simply not fully closed after use. Opening and then reseating the valve or cap might resolve the problem. Since you are inexperienced with propane tanks, probably best to drive the coach to a propane shop for more expert help.

 

[Isaac-1]

If it is the fill port on a fixed ASME tank, and it is leaking through the fill port and not around it you can add a stacker valve to it, there are multiple models of these made by Marshall Excelsior, they are commonly used by propane delivery truck drivers, they keep them installed on the end of their fill hoses, and if they find a leaking fill port on a residential tank, they can simply leave the stacker valve attached until the problem can be corrected. There are several versions of these some with bleed screws, some without, the M570, ME570 ME571 , ME572 and ME574 are common variants. The all do about the same thing, just with different features, swivel, non swivel, bleed screw, low profile, high flow, ball valve for positive cut off, etc.

I have the basic old M570 non swivel with bleed screw on mine (they don't make this version anymore), it basically acts as belt and suspenders for the occasions when my main inlet valve tries to stick open.

 

[Kirk]

Filled tank with propane and the fill valve spews propane

I would assume that you had the tank filled by a propane seller, and didn't fill it yourself? As Gary points out, the valve that supplies propane for use is not where the tank would have been filled but it should have been closed before the tank was filled and then opened again after the filling was completed. If you had the tank filled at a propane supply company then I would go back there first, and very soon. Leaking propane is heavier than air so it can pool in low places and when mixed with air be explosive. A propane leak is not something to put off.

 

[Rene T]

I would assume that you had the tank filled by a propane seller, and didn't fill it yourself? As Gary points out, the valve that supplies propane for use is not where the tank would have been filled but it should have been closed before the tank was filled and then opened again after the filling was completed. If you had the tank filled at a propane supply company then I would go back there first, and very soon. Leaking propane is heavier than air so it can pool in low places and when mixed with air be explosive. A propane leak is not something to put off.

And do it soon before you run out of gas

 

[House Husband]

My fill valve seal failed a few years ago. I found a new valve on the internet. I waited until the tank would not support a flame on the stove. (less than 11 in. water column of pressure). Unscrewed the old valve and very quickly installed the new valve, with teflon pipe dope on the treads. Still had pressure about atmospheric, so no purge was necessary.

Richard

 

[wesellyourstuff]

If it is the fill port on a fixed ASME tank, and it is leaking through the fill port and not around it you can add a stacker valve to it, there are multiple models of these made by Marshall Excelsior, they are commonly used by propane delivery truck drivers, they keep them installed on the end of their fill hoses, and if they find a leaking fill port on a residential tank, they can simply leave the stacker valve attached until the problem can be corrected. There are several versions of these some with bleed screws, some without, the M570, ME570 ME571 , ME572 and ME574 are common variants. The all do about the same thing, just with different features, swivel, non swivel, bleed screw, low profile, high flow, ball valve for positive cut off, etc.

I have the basic old M570 non swivel with bleed screw on mine (they don't make this version anymore), it basically acts as belt and suspenders for the occasions when my main inlet valve tries to stick open.

thank you that was most helpful

 

[Kirk]

Still had pressure about atmospheric, so no purge was necessary.

You were lucky as if significant air gets into the open tank it will become an explosive mixture and can be very dangerous. The fact that you got by without any explosions doesn't mean that someone else will be so fortunate. It is kind of like walking across a busy highway. You might do so safely 9 times but the fellow who is number 10 will die.

WE, think about what you are risking in order to save a few bucks? Do you wear a seatbelt when you drive? Not much different than this.

 

[Gary RV_Wizard]

You were lucky as if significant air gets into the open tank it will become an explosive mixture and can be very dangerous.

I don't want to belittle any safety precaution, but the air/fuel ratio for propane combustion is around 15:1, so it takes a LOT of air in an already fueled tank to get dangerous. The heavy propane remains in the bottom of the tank plus a fair amount of propane vapor above it. Just don't dawdle getting that new valve seated. And once you refill, venting a lot of gas as you do so (purging), you should be safe again.

 

[Isaac-1]

I had to change a leaking overpresure valve on mine last year, which required it to be empty and open for some time (I had to get the model number off the old valve). It was a very simple matter to have the propane supplier purge the tank before refilling.