Propane leak

[Rene T]

A little background. I have a fifth wheel with 2 30# propane tanks. One is on the passenger side and the other is on the drivers side. Next to the drivers side tank is the automatic changeover valve with regulator and it has the indicator. The tank on the passenger side has a small regulator which regulates the propane before it goes over to the other side through a 1/2" iron pipe. Recently, everytime I opened my front storage compartment door, I would get a smell of propane. Not much though. I finally ironed it down and yesterday using leak tek, I found that the small vent hole on the passenger side regulator had propane coming out of it.  This regulator has a sticker on the side which reads 30 PSI.  Also, this regulator is much smaller than the one's I'm use to seeing.

I have 2 questions: Do I really need that regulator or can I just remove it and connect the flex hose directly to the iron pipe?  If I do need it, is it a special regulator because of the 30 PSI sticker on the side and the physical size of it,  or can I use any regulator like the ones used on a gas grill? I was told by a service manager at a local RV dealership on a previous RV I had that it was not needed and the only reason it's there, is in case I ever got into and accident, only low pressure propane would come out of the pipe if the pipe severed. Was he right?  Thanks.

 

[Gary RV_Wizard]

Yes, that is a special regulator, special in that it is set to 30 psi rather than the usual(roughly) 0.5 psi. Is there a similar regulator on the other tank? Some RVs use a two stage regulator system, but it is not actually required - the second stage regulator can handle full tank pressure all by itself.

Not sure why there would be a regulator just on one side. 30 psi is still a lot of pressure and would make one heck of a blow torch, so I'm not buying the safety argument.

You can buy a 30 psi regulator on amazon.com or ebay, and surely from most any LP supply shop. Here are some on amazon:

http://www.amazon.com/s/?ie=UTF8&keywords=30+psi+propane+regulator&tag=googhydr-20&index=aps&hvadid=27880160130&hvpos=1t1&hvexid=&hvnetw=g&hvrand=209567133568738882&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_5spu7azkrk_b

 

[Rene T]

Thanks Gary
Yes I think it would make a heck of a blow torch. The drivers side had a huge regulator with the indicator and the change over valve. it's probably a two stage regulator. I'll have to look at it tonight when I get home. The line coming from the passenger side may hook right into the second stage without even going to the first stage and that may be why it's a 30 PSI regulator.  How does a two stage regulator work?  Does the high pressure come from the tank into the first stage then it goes to the second stage at a lower pressure then when it comes out of the second stage once again it's reduced. Is that how it works?

 

[Gary RV_Wizard]

Yeap, that's all there is to it. No magic, and if the primary regulator is any distance form the final one, the final has to be able to handle full tank pressure anyway.

A two-stage system cannot be interdependent unless they are physically integrated as one component. They make regulators like that, but yours doesn't seem to be that way.

Here is a 0-60 psi high pressure regulator at Tractor Supply for $20.
http://www.tractorsupply.com/en/store/mr-heaterreg%3B-high-pressure-regulator-with-pol

 

[Rene T]

That one looks like it's adjustable. I'll have to get a gage and set it for 30 PSI which would be no problem. I could even just leave the gage on it.

 

[Rene T]

I stopped at the local RV dealership and they were able to order a 30 PSI regulator exactly like mine for only 20.00 bucks.  I looked at the other regulator/change over valve assy. and it looks exactly like this:
http://www.pplmotorhomes.com/parts/lp-gas/propane-regulator-valve.htm

Both tanks tie into this unit adjacent to the indicator. Then the propane goes through the regulator shown at the bottom to the appliances. I still don't know why I need a regulator on the passenger side. The drivers side doesn't have it's own regulator. It may be a safety issue after all. Thanks for your help Gary.

 

[Master-Tech]

The second regulator on that tank basically keeps from line having full pressure from tank and not letting Liquid Propane into line which is bad Ju-Ju...  As well the 2 stage basically same first keep liquid out an tank pressure normal , 2nd regulates vapor whjch what all your appliances run on

 

[Gary RV_Wizard]

I fail to see much advantage inf a two stage regulation system, though. A single stage regulator does the same things that Master_Tech cited, i.e. traps any escaped liquid and holds the pressure at the required 11 W.C. inches (about 0.5 psi).  And whether you have one regulator or two, any liquid that escapes the tank and gets into the regulator  will usually stop it from functioning anyway, so the regulator is neither a filter nor a water separator.

This Article attempts to explain why a two stage is better for some applications. It makes the case that two-stage is better where the supply pressure varies widely, which is the case with an external LP tank when full vs empty or when outside temps change drastically. Practically speaking, though, single stage regulators have handled that application just fine for 30+ years.  I presume the engineers can demonstrate in the lab that two-stage yields a more consistent flow and pressure, but I have to wonder if the average RVer would ever notice.

 

[Rene T]

I picked up the new regulator yesterday and installed it last night. As of this morning, no more smell. The old one was the culprit.