Propane regulator went bad...need recommendations

RockyMtnRay · 07-01-2003, 04:52 PM

Came back yesterday from an 11 hour hike/climb of Pikes Peak to discover propane was leaking around the tank change valve handle on on my TM's propane regulator. Interestingly, it would only leak if the right tank was on (regardless of which tank the valve was pointed toward)...and the indicator was showing red (as in empty tank) regardless of which tank was on or which way the valve was pointed. Both tanks were full BTW. I shut off both tanks and semi-roughed it until I could bring the trailer home today.

It's been about a year and 20 days since I bought the TM so the regulator (a Marshall Model # 294) is now out of warranty.   :'(

So it seems that I have several options:

1. Buy a generic replacement regulator (Camping World sells a similar item made by "Mr Heater" for about $40) and either install it myself or, perhaps, have a propane dealer do the hose installation and leak testing. If I were to install it myself (only 3 hoses & 3 screws), what kind of pipe sealant should I use on the high pressure lines to the tanks? (the TM factory used some kind of red goop on the threads).

2. Take it over to the TM  dealer (The Car Show is only about a 30 minute cross town trip here in Colorado Springs) and have them get an OEM regulator and install it. The only problem is The Car Show's maintenance department tends to run a long backlog and I'm planning to take the TM out for another mountain climbing adventure on July 18th.

Bottom line: Is changing the regulator something that only professional technicians should do or can anyone do it with the right tools and pipe sealant...and do I need to stay with the OEM Marshall regulator?

**BobWilson** · 07-02-2003, 03:34 AM

Working with propane is not difficult. If it were me, I would do the work myself. Read your owners manual on the precautions of working with propane. Every manufacturer is going to give you warnings and make it sound like you have to have a contractors license to work on it. This is because they don't want to have liability on their hands for foolishness on the part of the user.

Fortunately the tanks are all outside of the TM and if you do the work outdoors, there should be little hazard or problem for you. Be sure to use good ventilation and keep all sources of heat and flame away from the area.

I would first make a leak detection fluid out of liquid soap and water in a spray bottle. Spray it on the regulator and all connections for your tanks including the hoses. Watch for bubbles forming to reveal the location of the leak. Make sure you pin point the all areas of leakage. You can go to any RV place for help since this is not unique to Trailmanor. When you buy your parts ask for thread sealant. I would use the teflon tape on the pipe threads only. When done make a thorough leak check again to verify that you have fixed the problem.

Be aware that when you flip the lever of the regulator there MAY be a little propane released to vent any trapped gas in the regulator. But it should completely stop when you let go of the lever. An RV dealer should be able to verify this.

**Bill** · 07-02-2003, 07:02 AM

When our TM was 6 months old, the propane regulator blew its cookies while we were in a campground in Payson, Arizona. We had time constraints and I didn't want to deal with it myself, so I hitched up the TM and towed it to a small RV shop in Payson, where the owner replaced it on the spot. Wish I could remember the name, I'd give him a plug. Since it was just him and me, I looked over his shoulder and chatted with him as he did the job. One of the things he said was "Never use a sealant or teflon tape on a propane connection." He torqued down on the brass connectors until I was afraid he would strip them, but he didn't, and it has worked fine to this day.

I don't know why he advised against sealant or tape, but he has a lot more experience than I, so I accept it.

So I pass that advice on to you. It is easy to do the work yourself. Use no sealant. Don't be afraid to REALLY tighten the connections. And, as was suggested by another post (and as the RV shop owner actually did), use a soapy-water leak detection when you are done.

BTW, Marshall Brass reimbursed me, without question or delay, for my out-of-pocket costs of both the new regulator and the installation labor. A GOOD company. Now this is the same trip where I lost the left TM brake coming down a very long steep mountain grade, and Dexter Axle screwed me over on the warranty repair. A BAD company. Dexter, you did NOT make a friend here.

A final note. The labeling on tubes of pipe thread sealant and rolls of teflon tape mentions suitability for "gas connections". To the best of my knowledge, this phrase refers to low-pressure natural gas from a pipe under the street - not high-pressure propane gas.

Bill

**BobWilson** · 07-02-2003, 10:20 AM

I was afraid this was going to turn into such a technical discussion that it would only confuse the issue.

Propane vapor pressure in the tank varies depending on the temperature, about 50 psi at 0 deg F to 300 psi at 120 deg F. That's not really high pressure by industrial pneumatic standards. Pressure is reduced to less than 1/2 psi by the regulator before it is distributed to your appliances.

Teflon tape is a controversial topic. You will find many sources that recommend it and some that don't. Even some local ordinances that don't allow it. The only reason I can think of is that the tape can shred and come loose in the system if it is installed beyond the end of the fitting. This could clog the regulator and cause it malfunction. National Pipe Threads are a tapered pipe thread which means they seal by an interference fit. The tighter you go the more it deforms and the more surface area to seal. We in the Navy use teflon tape up to 3000 psi in some systems. Some pipe fitters will only use the liquid pipe dope teflon for gas systems. More than sealing, the Teflon lubricates the threads so it can be turned more easily so you can tighten it more. There is a yellow teflon tape that is heavy duty and recommended for gas systems up to 10,000 psi. Again this is for tapered pipe threads not flare fittings which seal at the beveled end of the fitting. Some documents that state not to use teflon on propane systems don't address the type of fittings used. I personally still would use the teflon tape. I have used it for years on hydraulic, water and gas systems. But if you have good threads and you can tighten it up until it doesn't leak, that should work. Trailmanor used some kind of sealant on the threads for my TM. Again, a qualified RV repair place would probably be your best source of current practice and supplies.

Here are some interesting websites if you want to read more about propane systems.

http://www.boatus.com/boattech/casey/18.htm

http://dev.obatadesign.com/clients/E...rb/cs-200w.pdf

Working safely with a propane gas system
http://www.rvmobile.com/Tech/Trouble/gassafe.htm

Bob W., Mech Engineer

RockyMtnRay · 07-03-2003, 07:00 AM

Thanks for the advice fellers...and a particular thanks to Bob for the links on LP gas safety in RVs and boats. The boat link said: "The rule is that when the threads form the seal, you need Teflon tape, but not when the seal is formed with a flare, O-ring, or other compression fitting. " The RV link had almost identical advice.

Soooooo...armed with good guidance, an identical replacement regulator (only $41 from a real-close-by-and real-good RV dealer (Pikes Peak Traveland, http://www.pikespeakrv.com/), some teflon tape, and just-in-case, some flare wrenches, the replacement process only took about 20 minutes even at a deliberate and careful pace. The hoses to the tanks connected to the regulator with flare fittings (didn't use teflon), the hose out to the TM itself used a pipe thread fitting so I did use teflon on this one. Snugged all three connections down real good, turned on the tanks, and then sprayed all connections with a handy-dandy little bottle of "Leak Detector" fluid  Nary a bubble was to be seen, nor a hiss to be heard, nor a smell to be smelled. And the little green thingie popped up just like it was supposed to. I am (or will be the next time I go out) once again a happy camper  

Yeah, I know I could have mixed up my own leak detection fluid but it was so convenient to just buy the little spray bottle of it...and now I'll have it with me on future trips.

BTW, Pikes Peak Traveland had a whole bin of these Marshall 254 regulators in their parts store...apparently they're fairly big sellers which would indicate that failures aren't that uncommon (and I was afraid I would have to order one). So, hopefully, my little experience will be helpful to others should they have a regulator failure.

07-04-2003, 09:00 AM

When I purchaced my TM, the regulator on it came with a blown out diaphram. I simply purchaced a new one, and installed it myself. And NO, you do not use the white teflon tape for the connections, the proper sealant for propane is the yellow variety it is rated for the higher pressures associated with gases, as opposed to the white, which is rated for pressures associated with liquids. It can be purchaced in both a tape form, as well as a squeeze tube type. I used the squeeze tube type on mine, and have not had a single problem since. Oh, and btw, you are *not* supposed to use *any* sealant where the fittings go into the propane tanks themselves. These fittings seal in a different way.

[glow=red,2,300]Happytrails.........[/glow]

RockyMtnRay · 07-04-2003, 09:14 AM

However, the outlet connection of the regulator (only connection appropriate for the tape) is at a pressure of only about .5 psi (actually 11 inches of water column). At that miniscule pressure (far less than even the pressures in water systems), the white tape is more than adequate.

If teflon tape were to be used on the high pressure lines (e.g. the lines to the tanks ahead of the regulator), then the yellow variety would be necessary.