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Topic: Need to re-seal the LP fill valve (Read 2223 times) previous topic - next topic

Need to re-seal the LP fill valve

My LP fill valve has a slow leak on the bottom. My plan is the finished bleeding the LP gas (on E now) and use my large wrench to unscrew the fill valve, seal it, and screw it back on.

Q) Which is better, the yellow LP tape or the pipe thread sealant?

I made the HUGE mistake of filling the tank two months ago. It took DAYS to release the LP gas into the air. I only have the cooktop and the fridge that work on LP. I'll never fill that tank more than 1/4 ever again!

Re: Need to re-seal the LP fill valve

Reply #1 –
That looks more like a flange seal. What are you referring to when you say "unscrew it" If it is the bolts you are talking about it would take a gasket.

Re: Need to re-seal the LP fill valve

Reply #2 –
I am sure you will get lots of answers for this one so I'll start it off. I would use Gasoila pipe dope. My son works with propane and that is what he recommended for me to use on my propane leaks. It worked.

Roland

Re: Need to re-seal the LP fill valve

Reply #3 –
If your concerned about a possible spark from a regular wrench metal against metal, you might try to find a brass wrench when working around propane.

Re: Need to re-seal the LP fill valve

Reply #4 –
i would replace the whole valve. The rubber sealing surface hardens with age and starts leaking. 20 yrs is a good run. Should come out fairly easy with a 3/4" socket set. Harbor freight $39 cannot be beat.

Craneman: it is threaded into the flange. Most likely the threads are leaking, not the flange.

Re: Need to re-seal the LP fill valve

Reply #5 –
Many U270 & U295 coaches of these model years had propane tanks with an unused capped-off liquid valve, in addition to the standard vapor valve that is on every tank.  Liquid valves allow a safer and quicker transfer and recovery of tank contents.

Re: Need to re-seal the LP fill valve

Reply #6 –
I have say that our coach has the " unused liquid valve" that I elected to use for refilling the small  1lb camp stove /  heater type bottles. Everything worked excellent for refilling these UNTILL I couldn't get the valve to shut off.    That was scary untill I finally did get the valve to shutt off.

Of course I called the local propane co. For a fix and of course the obvious answer was to empty the tank and we will install a new valve.

I guess this liquid valve hasn't been used for 20+ years and shouldn't have trusted it. Now I will need to use up the hole dang tank of fuel before a repair is made.

Re: Need to re-seal the LP fill valve

Reply #7 –
I have never had any work required on mu propane tank or valves.
I feel a bit of preventive work in this area should be done.
Do most propane distributors replace the valves if you bring it in on the tank?

Re: Need to re-seal the LP fill valve

Reply #8 –
It is not leaking at the plate with the four bolts. It is leaking where the valve screws into the plate.  I have sprayed soapy water over all of the fittings and everything is tight except that one valve.

I did call all of the local propane places. First, none of them empty the tank. We spent days out in an open space releasing the entire tank of propane into the air. Second, they all referred me to the local RV shop to do the repair. I called the local shop and the service manager was a first class jerk. We full-time so I did not want to leave my coach. He boldly said I'd have to "drop it off go to a nearby restaurant for breakfast" since he did not want someone looking over his shoulder" while he worked. That is when I decided to fix it myself.  I am really tired of RV repair shops that do really poor work and that includes one of the official Foretravel service centers!

Re: Need to re-seal the LP fill valve

Reply #9 –
When we had to empty our tank to make a repair, the propane tech connected a hose between my liquid connector and an empty tank.  Then he drained our tank into his tank, and later even gave us $ credit for our propane.  With this technique there is no reason to wait until tank is used up to make repairs.

Re: Need to re-seal the LP fill valve

Reply #10 –
To answer viewrvs question,why don't you just try and tighten the valve?I would get a new threaded valve because when you remove
that old valve to put the tape on it's going to get out of round and will never seal.

Re: Need to re-seal the LP fill valve

Reply #11 –
On a related issue, if the valve itself starts leaking, the attached PDF has an adapter that screws on and fixes the problem. My propane dealer fixed one for me years ago so I found a source for new ones.

TOM

Re: Need to re-seal the LP fill valve

Reply #12 –
Quote from: John44 –
To answer viewrvs question,why don't you just try and tighten the valve?I would get a new threaded valve because when you remove
that old valve to put the tape on it's going to get out of round and will never seal.
If you install a new valve I would still use "Gasoila" to seal the threads.

Roland

Re: Need to re-seal the LP fill valve

Reply #13 –
Tom has a great idea, and we all (who have propane tanks) need to carry it.  Sometimes the propane filler check-valve fails to close after the hose is removed, causing the valve to leak.  Most fill shops have a handy short piece of 2x4 wood they use to hit the side of the fill valve to try to seat the check-valve.  If that does not work we have a looming disaster with a problematic valve that will not stop leaking.  Screwing on Tom's adapter is a 100% permanent safe resolution.  We have carried this adapter hanging on front of the propane tank in a sealed bag for 20 years awaiting its call to duty.

Re: Need to re-seal the LP fill valve

Reply #14 –
Good backup.  Purchased one even though I have already replaced the fill valve fairly recently

Re: Need to re-seal the LP fill valve

Reply #15 –
Fred,
Tape or pipe dope:
Pipe dope.  Try RectorSeal No 5 available from Homedepot for $8.  It thickens and is a "Soft Set".  When they connect the LP Fill Hose to your Connection the nut could jam and its possible for your connection to loosen or unscrew if you use tape.  Actually the Gasoila Hard Set is better but it costs twice as much and can only be used for Chemicals.  For use on a motorhome  RectorSeal No 5 has more uses as it is CSA and UL listed for NG, Propane, Gasoline, Diesel also NSF listed for drinking water :).  It will be more than sufficient for this application.  All my homes have had Propane and I've used it for 30 years. 
Tape is more difficult to apply properly.  Either not enough or too much.  The tape "strings" and travels downstream, plugging Pilots, or worse causing Regulators to leak-by causing an overpressure failure.  Most equipment manufacturers forbid tape usage.  I used teflon tape almost daily for the past 25 years performing instrument maintenance in a Refinery and a Petrochemical plant.  When I need to seal pipe and then reuse it, I use tape.  For permanent applications that I don't anticipate redoing, it's dope. 

Re: Need to re-seal the LP fill valve

Reply #16 –
Quote from: TexasPop –
Fred,
Tape or pipe dope:
 Actually the Gasoila Hard Set is better but it costs twice as much and can only be used for Chemicals. 


Not true there are many different types of gasoila some soft set hard set and for many applications. As I stated previously my son works with propane and that is what they use as a pipe sealant on propane systems. Check it out at Gasoila Chemicals – Specialty Products for Today's Professional

Roland

Re: Need to re-seal the LP fill valve

Reply #17 –
Gasoila makes many products that are listed for Propane usage, along with a dozen other speciality sealants.  Nothing wrong with them.  I can right now, ask the Tool Room attendant in my Oil Refinery for RectorSeal, Loctite, CRC, or Bostich liquid sealants.  I will choose depending on chemical, material, pressure, temperature or application and can order many others if needed.  All will work for Propane.  I've worked with Crude Oil, Natural Gas, Diesel, Gasoline, Butane, Naptha, Ammonia, Hydrogen, Nitric Acid, Sulfuric Acid, Adipic Acid, HF Acid, C6, C12, Molten Sulfur, H2S, SOx, NOx, COx, and many others ranging from Temperatures of -300 to 3500 F and Pressures from Absolute Zero to 50,000 psig.

But the only one that I can get everyday 7a-9p from Lowes, Homedepot or Ace that has multiple uses on my Motorhome is RectorSeal No 5.

But my main point is DO NOT USE TAPE...

Thanks,
Dan

Re: Need to re-seal the LP fill valve

Reply #18 –
Fred,

You may want to look at Curtis's excellent write up; Propane Tank float valve fitting Modification

By viewing your picture it looks like you have the same Brown Mfg Corp valve that is probably no longer available and will need to be replaced.

The only time that I have filled my tank it spewed out and I simply inserted my finger to reseat the valve.  All was well.

Keep us posted.  I'm looking at the same repairs this winter,

Dan

Re: Need to re-seal the LP fill valve

Reply #19 –
Just a follow-up. I have the tank empty. The cooktop finally burned out.  Now I need to remove the fill valve and re-install it by applying the sealer and screwing it back in! 

After more research, the yellow tape and the Rectorseal 5 (yellow tube) is only good for up to 100 psi.  The would work for LP AFTER the regulator but not for the valve on the tank. It is normally used for natural gas that has a low psi. The LP tank itself will have between 150-275 psi. I ended up getting the Rectorseal 'T plus 2' that is rated for up to 10,000 psi.