LP gas lines and fittings

[The Twinkie]

Happy New Year to all.
When it warms up to above freezing we will be setting the 2 tanks on the tongue, attaching the regulator and running a line to the water heater (with a "T" off of it to the 3 burner top). Lines to be attached underneath the floor (no belly pan).
I'm needing advice:
I'm concerned about vibration ....(A) is a 3/8 stainless wrapped rubber line (Google search) attached securely to the underbelly the way to go..... OR....(B) should I run 3/8 copper and come off of it with rubber hose to just before the WH and cook top?
Have you seen or heard of leaks from rigid copper?
They've used it for years so B is probably the way to do this???!!!
Thanks

[polarlyse]

I'm no expert. In fact I suspect you'll get advise from many directions but I think I would avoid using SS. It's more brittle than copper and may crack with the vibrations caused by road travel. SS is also more difficult to make flared connections and you may need to use other types that are not best used under these conditions. Copper w/ flared connections has been used and tested and is the way I suggest you stick with.

[55AS]

In all my vintage AS trailers the LP lines have been rigid copper all the way to the appliances (no flex lines). Even the 50+ year old lines are still performing fine...

[featherbedder]

Originally Posted by BambiTex

In all my vintage AS trailers the LP lines have been rigid copper all the way to the appliances (no flex lines). Even the 50+ year old lines are still performing fine...

May be misunderstanding of name of copper as rigid and soft. Rigid is very hard and I don't no if can be flaired, at least I can't do it, soft very easy to flair. In my usage with both types in over 65 yrs never seen rigid used any where except in plumbing as joints are soldered not flaired, soft can be used mostly every where, so bottom line, never rigid only soft in tt.

[55AS]

Originally Posted by featherbedder

May be misunderstanding of name of copper as rigid and soft. Rigid is very hard and I don't no if can be flaired, at least I can't do it, soft very easy to flair. In my usage with both types in over 65 yrs never seen rigid used any where except in plumbing as joints are soldered not flaired, soft can be used mostly every where, so bottom line, never rigid only soft in tt.

Yes, soft copper. More rigid than flex line but not truly rigid. Flares easily.

[Air4563]

If you are planning to replace the belly pan,I think code requiems the fas lines to run under the belly pan until you get to the appliances

[polarlyse]

Something tells me that the intent is to keep the connection OUT of the belly pan. Connections are likely where leaks will occur and outside will simply vent itself and if it's leaking indoors you will smell it and the detector will sense it. But in the belly pan it may accumulate and therein lies the danger.
And YES, hard copper can be flared to make fittings using the proper tool.

[eubank]

Yep, codes are going to require that propane be allowed to flow out and away from whatever it's in. In this case, it's a pipe, but the same reason requires, for instance, that RVs that use compartments for propane cylinders to be open to air at the bottom. For that matter, the same requires large propane tanks (e.g., 500 gallon ones) not to be surrounded by a fence; one side must be open so that propane can flow away and dissipate.

You can look it up in the NFPA #48 propane book, but you'll have to battle your way through a lot of engineering-speak. Better just to get the info from somebody who has had the pleasure of studying the book and can just tell you what it says.


Lynn

[55AS]

I think the OP said he has no belly pan. He is talking about running the piping under the floor but the important thing is that they are in the "open" where any leaking gas will not enter the trailer.

[The Twinkie]

Clarification:
Will be using the soft 3/8 copper rolled up in a box.
I found a schematic on the "Handyman" site....many thanks for the feedback.
"Have flare tool: will travel"

[Chillitom]

I just redid all of my gas lines use 3/8 soft type L designed for gas

[Dingo Girl]

Could you post a couple of pictures please?

[A W Warn]

My trailers have a larger soft copper tubing that runs from the A frame to the first appliance (the furnace), either 1/2 or 5/8 (CRS kicking in ;-), then branches to everything else beyond there using 3/8. On my trailers, all of the gas piping is soft copper except for a 36" rubber gas hose between the regulator and the end of the copper where the copper terminates at the A frame.

Where the smaller tubes run from beneath the trailer to where they connect to the appliance, there should be no joints made within the belly pan or cabinets. This is so that all of those mechanical/flared connections are exposed and a leak can be more easily found/repaired if one should occur.

If you would like to protect the soft copper from road debris where it is exposed beneath the trailer, one way is to slide the copper tube inside a PEX pipe between the compression fittings. On my Safari it was done this way by Airstream.

[ALUMINUMINUM]

Propane system is installed after bellypan is secure. Propane supply system is all outside the trailer until below appliance, then goes up/through pan and floor directly to appliance. Flared to appliance.


My original 1968 propane configuration was as assembled by Airstream. The fifty year-old system had no nicks, scuffs, or dents from road debris, and was wholly intact. There was no chafing at the aluminum clamps. No green oxidation.


I reconfigured the original system with new tubing in accord to my relocated appliances. Rearranged 1968 Airstream Factory Specs.


My 50yo brass seemed much nicer than new, so I cleaned and re-used it. Soaked in toilet bowl cleaners like “Vanish” will make it shinier than new, then inspect for cracks and smooth seats. Every union is outside trailer with no flexible hoses inside trailer.


Double flare is superior for high pressure like hydraulic brake lines, but single flare is common to trailer propane. Most outlet pressure of second stage propane regulators are measured in water column inches, eg. 11” water column (0.4 PSI). 28” is 1 PSI. A healthy human can blow 2 PSI.


Sequence is:
40# Tank
Flexible tank hose
Regulator
pipe to flare conversion
1/2” “soft/roll/coil” copper (5/8” OD) Main trunk
1/2 to 3/8 'T' appliance supply branch
3/8 flare at appliance


Following safe propane guidelines, Seems the same as it ever was...

Be Safe

[featherbedder]

I installed brass shut offs at each appliance in case of failure of one won't have to shut main supply off, all out side of belly pan not at appliance end. Use t handle valves not round handle such as used for water. HD has these valves very cheap.

[Dingo Girl]

Nice photos!
Also great idea to reuse the old brass.
Lots of good info here.

[Dingo Girl]

The grey boomerang is perfect.

[bjen5en]

Originally Posted by ALUMINUMINUM

Propane system is installed after bellypan is secure. Propane supply system is all outside the trailer until below appliance, then goes up/through pan and floor directly to appliance. Flared to appliance.


My original 1968 propane configuration was as assembled by Airstream. The fifty year-old system had no nicks, scuffs, or dents from road debris, and was wholly intact. There was no chafing at the aluminum clamps. No green oxidation.


I reconfigured the original system with new tubing in accord to my relocated appliances. Rearranged 1968 Airstream Factory Specs.


My 50yo brass seemed much nicer than new, so I cleaned and re-used it. Soaked in toilet bowl cleaners like “Vanish” will make it shinier than new, then inspect for cracks and smooth seats. Every union is outside trailer with no flexible hoses inside trailer.


Double flare is superior for high pressure like hydraulic brake lines, but single flare is common to trailer propane. Most outlet pressure of second stage propane regulators are measured in water column inches, eg. 11” water column (0.4 PSI). 28” is 1 PSI. A healthy human can blow 2 PSI.


Sequence is:
40# Tank
Flexible tank hose
Regulator
pipe to flare conversion
1/2” “soft/roll/coil” copper (5/8” OD) Main trunk
1/2 to 3/8 'T' appliance supply branch
3/8 flare at appliance


Following safe propane guidelines, Seems the same as it ever was...

Be Safe

I like that you added an outdoor appliances line. I'm running new propane now and would love to do that. Curious where you routed that and what your setup is for this connection.

[ALUMINUMINUM]

Hi there,


I didn't check if what I did meets trailer codes. I branched off the main trunk to the curbside, aft of the axle's wheelhouse... It has a shut-off and a rubber cap. There's a little aluminum mudflap to protect it. It's a good place for the 68GT.



The quick disconnect propane fittings are found anywhere they sell propane accessories, like Tractor Supply or if you're near Texas, ask for Hank Hill at Strickland Propane. Hank's an Expert.







Be Safe


.

[Dingo Girl]

Hank Hill really is the propane expert.
:-)