1970s Gas Line Replacement?

[tonydead]

1976 Caravanner. Replacing just about everything else including water lines with pex. It's hard to tell what shape the old copper propane lines are in. Should I just plan on replacing? Is the best thing to do a replacement in the same location underneath with new copper lines?

[featherbedder]

If old lines are in good shape [no corrosion or damage] IMO I would not replace but if you do I would run same place as original unless rubbing or damage. Use good flareing tool check for leaks when finished.

[Jammer]

Inspect closely, replace if there are leaks, significant corrosion, or mechanical damage.

They may be fine, or not. It really depends on where the trailer has been (salt) and where it has been driven (gravel).

[mimiandrews]

The propane lines run beneath the trailer in case there is a leak. Propane is heavier than air, and moves downward. This helps keep leaking propane from accumulating in the living space.

[TomKirk]

Pressurize the gas lines. Check for propane leaks with bubble solution (dish soap and water) and small paint brush. Take your time when you do this.

BTW - Pressure is only 7 PSI or so. So it might take a minute or two for bubbles to appear. Also, be on the look-out for propane odor. Trust your nose. If you think you smell it, it's because you do.

BTW - They also make a propane sniffer:

https://www.google.com/#q=propane+sniffer

Be sure to check brass fittings for cracks, especially flare nuts. Flare nuts should be good and snug, not over-tight.

BTW - They also make a propane-friendly Teflon sealant and Teflon tape - good stuff to have in your tool box.

Tom

[tonydead]

Thanks for all the info. Without a microscope inspection they just look like they are 40 years old and I'm replacing everything it will service so I think I might as well put in brand new. Just regular copper? Where to get ? No alternative or better material?

[ijustlee]

Don't use the cheap copper water line, use the refrigeration grade copper.

[mimiandrews]

Also, today's code requires double flares on propane lines.

[prairieschooner]

I replaced mine just because it made me more comfortable. Afterwards I found a section that was questionable and would not have been able to see it without removal.
Your call but.....................

[TomKirk]

Use copper tubing "L" series (definitely not rigid pipe), it bends easily. Pay close attention to sizes. Even when you measure carefully, it's not what it seems.

While you're at it, you should replace flare nuts.

Hint: I.D. of flare nuts will tell you what size(s) tubing you need.

Tom

[tonydead]

Thanks for the tips. I saw some flexible coated gas line at home depot that looked like it would work great, but, I think that was for natural gas.

[mimiandrews]

The flex coated tubing will not stand up to the vibration. The motion of the trailer will cause it to crack and leak.

[TG Twinkie]

Why not consider using a rubber hose specifically made for propane? The regulator(s) are connected with such a device. Propane dealers in most cases have the ability to fabricate such a hose.

[featherbedder]

Originally Posted by TG Twinkie

Why not consider using a rubber hose specifically made for propane? The regulator(s) are connected with such a device. Propane dealers in most cases have the ability to fabricate such a hose.

A rubber hose will not stand up to elements like copper does plus will not last as long a copper. Gas co. use a kind of plastic tubing for under ground, black iron coated outside but no galvanized pipe.

[tonydead]

What about braided stainless steel lines? Wouldn't they hold up under the trailer? And they come in various sizes with fittings so you wouldn't have to mess around with cutting and flaring the copper.

[tonydead]

Yep, after researching around and lots of youtube videos it looks like copper is still the best way to go. Might consider a black iron trunk line down the length of the trailer if there is room. Just going to practice making double flares on pieces of the old copper until I become proficient at it.

[my3sonsdad]

I've removed my gas lines temporarily while I do an eviction freeloading tenants in the belly pan. I've disconnected a minimum number of connections and other than replacing some very corroded shutoff valves, I was simply planning to reconnect (using sealant) using the original cooper tubing & flare nuts (they all look good so far).

Is this not a good plan or do I need to start practicing double flares?

[TG Twinkie]

My '74 Argosy has all original copper lines with the exception of the line to the new water heater and 4 feet of line from the regulator hose to the trunk line. The 4' was crushed by the PO using a jack under the tongue. Other than these 2 areas all lines are in good shape. I did replace the shut off valve at the water heater since the line had to be replaced. All other shut off valves still function.
Just check for obvious damage or excessive corrosion. Perform a leak check at all joints. Make sure the line(s) are supported well.

[TheGreatleys]

No sealant on flare fittings. Just a drop of 3 in 1 oil on the threads to facilitate tightening. The threads do not make the seal, the flared shoulder does.

IMO if a single flare lasted this long on the original trailer, no need to change it now.

[Jammer]

Ordinarily, single flare is used on gas lines.

As others have said, don't use sealant, just a little bit of oil.