Propane System Install


Does anyone have any good resources for propane system installation or modification? My google skills are letting me down and I haven't been able to come up with any firm advise.

My plan is to use 3/8" copper tubing with flare connections protected by split loom to extend some lines in our van for a new layout. The idea was simple enough until I had a hard time sourcing some of the materials locally; now I'm down the rabbit hole of what I actually need. Is there a spec out there for propane systems in recreation vehicles?

The internet is both a wonderful place of knowledge and a terrible place of incorrect knowledge. Some of the confusion I've run into includes:
  • Flare connections or double flare connections?
  • Flare nuts vs. forged flare nuts?
  • Tubing thickness - general purpose vs. type L/K?
I swear I'm trying not to over think it but since there is gas involved, I want to make sure I'm getting the right stuff.


Well-known member
The most frustrting part of doing propane is forgetting to put the flare nut on before flaring.

Use Type K copper

RV appliances are 11" water column also know as 1/2lb.

1st stage regs are take high pressure down to 10psi
2nd stage regs take 10psi down to 11"
Both stages are needed

The worst part about cheap flaring tools they allow the copper to slide through the clamp.

Single flare for gas. Double flare for brakes.

3/8" copper will work for most appliances but 1/2" maybe needed depending on the run and the number of BTUs

Here is a chart

On plumbing (water) the best way to prevent leaks is to used Teflon tape with non metallic pipe dope on the tape.

For gas use Master Metallic on the threads but not on the flares. Don't use to too much or get it inside the fitting. I've removed fitting from RVs that are partally filled with pipe dope .

Test fit the fitting before. You want the fitting to turn in 1 to 2 turns by hand. Fittings that turn 3-4 turns should not be used. They could be straight thread instead of tapered thread.

These people have all things propane.

Make sure the gas line is grounded to the frame of the trailer.

Secure with Nylon (P clips) or better yet rubber lined (cushion clamps) metal clamps

Rubber (-60F to 212F) hoses have a better temperature rating than plastics (-40 to 140F)

Copper needs to run continuous (no T, unions, elbows) from outside to the appliance

It is a matter of time before quick disconnects leak don't used them inside.

Strapping wires to gas line is a bad idea......obvious but I've seen it done.

Spring benders work great for retrofit work. Do some test bends so you have an idea of the min radii that can be bent.

This alarm can be set up with a dual sensors and a solenoid that will shut off the propane.

If the regulator is in enclosed space it must be vented outside

Consider using a shut off (outside, not at the appliance) valve for each appliance.

1 or 2 quick disconnects (with shut off) outside are always useful

****After all is done do a LEAK DOWN TEST and every year there after****
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The most frustrting part of doing propane is forgetting to put the flare nut on before flaring.

Use Type K copper


Amazing, thank you!

I was planning on having shut offs at every appliance where the propane enters the vehicle. I'm assuming doing it outside is to minimize the chance of leaks? Easy enough - just more time under the vehicle in the snow instead of inside. Haha. For those that have individual shut off valves, how often to you use them? My existing set up didn't have any isolation. It seems like a nice to have but do you use it often? I will have a propane stove, furnace and bbq. Other than the BBQ I don't see using the isolation that often.

On that note, what would be the best practice to hook up a BBQ? My idea was copper through the floor to a ball valve that then connects to flex hose for the BBQ. My idea is the valve is the "appliance" that I shut off after every use so in practice I still only have one live connection on that leg and it should be no more prone to leaks than the stove or furnace. The BBQ sits on a drawer that will slide in and out of the van, so having it on a flex hose of some sort is a pretty key part of the plan.


Well-known member
This the propane manifild in our trailer.
2 - multiport manifolds
100lb ASME onboard tank feeds thru the frame from the left. The valve on the top right is (1/4" inverted flare) plugged. In the winter we use this to connect portable 30-50lb DOT tanks.
The 2nd stage reg is vented out the bottom (black hose at back) and the compartment is (holes in aluminum) vented.
The door is off because I'm replacing the seals.


Fishing is life. The rest is details.
Oh duh. Don't I feel lame. In my defense, pic was too small on my phone to see the labels.

What's the thinking behind the two heaters?


Well-known member
The Propex is more efficient so we use it to heat the trailer in temps down to 32F. Below 32F the Surburban heater is needed but if it quits we can use 2 - 110V Caframo heaters in the living area while the Propex keeps the tanks from freezing.

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