Red propane pressure regulator

[Elk4me]

I had to remove the red propane regulator from the driver side due to the screaming noise it was making. I have noticed no issues without it. What is it's purpose when the crossover pipe jumper hose to the dual stage regulator is no different than the one that comes from the tank on the door (curb) side. I am a plumber and I have a lot of experience with pressure regulators on air and gas systems and I see no point of this regulator. I currently use a 100 lb 23 gallon tank on the driver side and the stock 7 gallon tank on the curb side. Am I missing something? I have been using it this way for a year now and have not observed any adverse issues.

[chuckster57]

That regulator keeps the pressure coming out of the tank to 30 PSI, and is required by DOT when on the road. It may also have a high flow shutoff built in so that in case of accident and the crossover line is severed, it will stop the flow of propane.

If your trailer is parked and your NOT going to take it on the road, you may be okay without it. FWIW, they are cheap enough to replace and not chance it.

[hankaye]

Elk4me, Howdy;

As you have a 100# vessel, does it have a "red" pressure reg. hooked to it
near the valve? Reason I ask is that when the propane co. came and hooked me up they installed the 125# tank and then removed my "red"
pressure reg. as they already had one installed on there tank. Same reg.
their hose hooked into my system at the black pipe then across the front of
the 5'er to the RV's pressure reg. with the switch-over valve.
In your signature you mention that you are a retired plumber and inspector
of stuff why not take a few minutes and stop by your local Propane shop
and ask a few questions from their Professional folks? They may even be
able to show you some regulations or something to show you the "WHY"
it's there.

hankaye

[bobbecky]

This is the reply to the same question that I discovered a while back on a forum for a different brand RV, and is was so well written, I saved it. I believe there is also some regulation that covers this, but the practical reason makes more sense.

The main reason for the red regulator is to make sure that once the propane leaves the tank as a vapor that it stays a vapor. Propane regulators in trailers do not regulate liquid only vapor. If the regulator was not there the pressure in the hose/pipe would be the same as the tank. This could lead to the vapor condensing back into a liquid. With a reduction in the pressure from the regulator to the other side of the coach this will greatly reduce the possibility of the vapor in the crossover hose turning back into a liquid. This is all based on propane’s vapor/pressure saturation points. The lower the pressure the lower the temperature to turn it back into a liquid.

[Elk4me]

Thanks for all the replies, that is what I like about this and other forums.

Bobbecky, I never thought of the liquid/vapor issue. It makes total since.

Hankaye, I have asked at one supplier and they didn't have an answer, but they also made me a hose up that didn't work so I am not surprised.

Chuckster, we are soon to be rolling again I hope. I did not see any indication of a flow restrictor in the regulator, it is just a single stage 30PSI regulator. There is the one in the hose to the crossover pipe.

I will be purchasing and installing another one soon.

[chuckster57]

I wasn't fully awake when I posted, the shut off is built into the cylinder valve assembly.

[bobbecky]

Actually, the flow control valve in the case of a broken hose or line is built into the ACME nut on the pigtails that connect the cylinders to the RV propane system. That is the valve that closes if you open the cylinder's valve too fast and then you wonder why your heater isn't working when your burner on your range does. The only valve inside the cylinder is the OPD, the Overfill Protection Device, which stops the flow of propane into the cylinder when the level approaches 80% capacity. An excellent discussion of the propane system is at the following link: http://home.earthlink.net/%7Ederekgo...like/id44.html

[chuckster57]

Boy I'm getting schooled tonite...all good, been a week if you know what I mean.

[Elk4me]

Originally Posted by bobbecky

This is the reply to the same question that I discovered a while back on a forum for a different brand RV, and is was so well written, I saved it. I believe there is also some regulation that covers this, but the practical reason makes more sense.

The main reason for the red regulator is to make sure that once the propane leaves the tank as a vapor that it stays a vapor. Propane regulators in trailers do not regulate liquid only vapor. If the regulator was not there the pressure in the hose/pipe would be the same as the tank. This could lead to the vapor condensing back into a liquid. With a reduction in the pressure from the regulator to the other side of the coach this will greatly reduce the possibility of the vapor in the crossover hose turning back into a liquid. This is all based on propane’s vapor/pressure saturation points. The lower the pressure the lower the temperature to turn it back into a liquid.

I found this at Arlington RV Supply and Repair in Arlington, WA (I recommend them for supplies and just good people). I purchased a new regulator from them and will install it today. I will send this to Admin also and possibly make it a "sticky" for this part of the forum. It explains this issue very well.

[chuckster57]

Nice find!! I'll contact the other site team members and let you know about making it a sticky.