Gas Lines

[Vicki A.]

I am at the point of replacing the lines coming into the trailer to the stove and fridge. While at the "depot", I saw flexible lines used in homes for ranges, water heaters, etc. Does anyone know if that would work in the egg?
Sure would be a lot easier than trying to bend the copper, flaring and all.
Tell what ya'll think!!

[Joe MacDonald]

short and sweet: No!!!

[SherryNPaul]

Joe, I'm really curious as to the quick... NO! ?
In my restaurant, all the fittings to gas equipment ran from the fixed pipes on the entry wall to the grill, stoves, fryers, etc., with extremely heavy duty, at least semi flexible gas hose (blue, I think, in color). This allowed the equipment to be pulled away from the walls for cleaning daily. Each piece on the line was fitted with a quick disconnect, and there was a central shutoff for the entire line, and also for the whole kitchen.
If that met code, in a situation with hundreds of people allowed in the building, under the license, why wouldn't it meet code in a trailer?
I claim absolutely no expertise in gas fittings and lines, and therefore always hire an expert. However, I'm curious. It would seem that a flexible line in a vehicle that, well.... flexes... would make some sense. For example, I suspect that the big coaches with slideout kitchens must have flexhose gas connections, wouldn't they? How else could a kitchen "slide"?

Not saying that Home Depot gear is the answer...

Sherry

[Dave Bese]

RVIA specifies that the main run is black iron pipe with connection to appliances with short runs of flexible copper. Main run is to be under chassis with only connecting line thru the floor.

[artspe]

Joe, I'm really curious as to the quick... NO! ?
In my restaurant, all the fittings to gas equipment ran from the fixed pipes on the entry wall to the grill, stoves, fryers, etc., with extremely heavy duty, at least semi flexible gas hose (blue, I think, in color). This allowed the equipment to be pulled away from the walls for cleaning daily. Each piece on the line was fitted with a quick disconnect, and there was a central shutoff for the entire line, and also for the whole kitchen.
If that met code, in a situation with hundreds of people allowed in the building, under the license, why wouldn't it meet code in a trailer?
I claim absolutely no expertise in gas fittings and lines, and therefore always hire an expert. However, I'm curious. It would seem that a flexible line in a vehicle that, well.... flexes... would make some sense. For example, I suspect that the big coaches with slideout kitchens must have flexhose gas connections, wouldn't they? How else could a kitchen "slide"?

Not saying that Home Depot gear is the answer...

Sherry

Sherry,
The flexible gas lines used in restaurants is extra heavy duty and costs hundreds. Residential gas connectors are VERY thin walled and can not take any abuse. Would probably not be a good choice for a trailer. Ward Flex, Trac Pipe etc. are also very thin walled and I don't think a good choice for a trailer. I believe soft copper tubing is the best compromise for gas piping a trailer.

Art

[SherryNPaul]

Art, I would absolutely agree that the gas connections in a restaurant are not only extremely heavy duty, but extremely expensive. I also doubt (as you'll see in my first response) that residential products would be suitable for a trailer moving down the road.

I am curious, if anyone has seen them, as to how the propane connections are made in the buses with kitchen slides. I would suspect this is an expensive, heavy duty product... and flexible.

Please don't take my comments earlier as a recommendation for using household products in an rv gas supply. I, too, think using residential products, designed for a stable environment, could be a serious, and dangerous, mistake in an rv.

Sherry

[Donna D.]

Interesting topic. Maybe this article is worth reading:
RVIA STANDARDS AND EDUCATION DEPARTMENT - RV Propane Systems

On edit: oooops I see to see the entire article costs $49.95, dang.

[Dave Bese]

How many really, really smooth roads do you travel? Vibrations are not common to a restaurant (except in CA). Resudal propane in copper creates hydrogen sulphide (poison); so the length of copper should be as short as possible. As you would travel down the road, the flextube would do what it does . . .flex. This leads to work-hardening, which makes the metal hard and subject then to cracks

[SherryNPaul]

Dave. I think we all got that. Most of us here like the "road less traveled", even if it includes vibrations, bumps, and detours...

I should probably have included in my original post the pricetag of the flexible gas hoses in restaurants... fifty to one hundred a foot...but they're much larger diameter hoses than anyone would use in an rv,.

Obviously, even paying for expert installation, copper is cheaper, and considered "flexible" by RVIA code, because of the soft nature of copper (this benefit being also a problem, because you have to make sure there are no sharps nearby... as in screws, hangers, clips, nails, etc. that could abrade and puncture the line), and is recommended for the shortest run possible.... just to connect the gas-consuming equipment.

I'm afraid I kind of hijacked the original op's question,(and I apologize to her) wondering how the big buses connected the equipment in kitchen slideouts. If I had to guess, they use a marine grade braided stainless lp flexible tubing (also very expensive), as has been used for decades in boats. Perhaps, someday, this will be reasonably available in the rv market. Till then, I think copper is probably the standard in trailers, in the shortest run possible, with expert installation to prevent safety issues.

Again, I am NOT advocating residential flex tubing in a trailer. I, too, would consider that a serious safety hazard.

Yikes!

Your answers gave good background, and were very helpful, in assisting the op in making a good decision in what to do in her trailer, and I thank you for that.
Sherry

[Joe MacDonald]

looks like every one jumped in before I got to reply, they seemed to have covered all the points I was considering.

Joe

[Vicki A.]

Well.... I guess I got my answer !
Actually, I understand the answer is NO NO NO!

Sherry - don't worry about the "hijack" - this was an interesting dialog.

Thanks to everyone for the interaction- this is obviouisly a very passionate subject - due to SAFETY precautions, and we all want to stay safe.

Vicki

[Mike Bromley]

[Residual] propane in copper creates hydrogen sulphide (poison);

I'm interested to know more about how Propane (C₃H₁₀) and copper (Cu) can make hydrogen sulphide (H₂S). Is there some residual sulphur from the smelting process or some not refined out of the propane? That sounds not right from a chemistry standpoint.

[Dave Bese]

Ever see the blue or green oxidation of copper? Sulfides of copper. We cannot get inside the tube to clean so it will, over time accumulate.

[Don'n'Deb]

Well.... I guess I got my answer !
Actually, I understand the answer is NO NO NO!

Sherry - don't worry about the "hijack" - this was an interesting dialog.

Thanks to everyone for the interaction- this is obviouisly a very passionate subject - due to SAFETY precautions, and we all want to stay safe.

Vicki

I used hose from Lowe's (intended to hook outdoor BBQ to NG) to replace to copper tube (wife recycled) in my Compact JR . Works just fine.

[Victor Benz]

I agree that the residental flexible tubing will probably not stand up to the constant vibration that a trailer undergoes as it is being towed, aside from the fact that trailer manufacturers here are not allowed to use it.

In my unit, I had noticed some wear on the copper piping where it passed through the trailer floor, so I replaced it. One addition I have done to further protect the copper piping is to split an old garden hose and wrap it around the copper sections of piping under the trailer and up through the trailer floor.

Vic

[Greg A]

Reading through the NFPA 1192 guidelines for gas line materials it appears that the residential flexible line would be fine. Items (i) and (J) in the regulations below is what if I recall correctly the residential flex line is, steel tubing with a corrosive protective covering. Don't see anything in the piping material regs in 1192 (below) that would prohibit it's use or the the RVIA adopted standards for fuel line. That doesn't mean that there could be something in this mess that could prevent it's use somewhere, but I haven't specifically located a reg that prevents it's use.

I've used the flexible gas line on my Scamp for the run from the fridge to the propane tank and they've been in place for over two years, lots of miles and no visible wear or leak test failure. In fact I feel much more confident with the flex lines then the mess they replaced. If I were going to replace the entire internal gas line system of a larger trailer I wouldn't use the flex, but for a short run in the small trailers seems like it would be fine and it has stood up in the field. With gas systems I think the key is to always be vigilant, leak test regularly, and replace any parts that show wear.


NFPA 1192:

5.3.2 Gas Piping System Materials.

5.3.2.1 Materials used for the installation, extension, alteration, or
repair of any gas piping system shall be new and free from defects
or internal obstructions.

5.3.2.2 Inferior or defective materials in gas piping or fittings shall
be replaced and shall not be repaired.

5.3.2.3 Inferior or defective materials shall not be used.

5.3.2.4 The system shall be made of materials having a melting
point of not less than 1450°F (788°C), except as provided in 5.3.5
(2-4.5), 5.3.6 (2-4.6), and 5.3.12 (2-4.12), or of materials (used in
piping or fittings) listed for the specific use intended.

5.3.2.5 Gas piping system materials shall be permitted to con sist of
one or more of the following materials:

{a} Gas pipe shall be steel or wrought-iron pipe complying with
ASTM A53, Specifications for Pipe, Steel, Black and Hot-Dipped,
Zinc-Coated Welded and Seamless.

{b} Threaded copper or brass pipe in iron pipe sizes shall be
permitted to be used.

{c} Fittings for gas piping shall be wrought iron, malleable iron,
steel, or brass (containing not more than 75 percent copper).

{d} Brass flare nuts shall be stress relieved or of the forged type.

{e} Copper tubing shall be annealed Type K or L, conforming
to ASTM B 88, Standard Specifications for Seamless Copper Water
Tube, or shall comply with ASTM B 280, Specifications for
Seamless Copper Tube for Air Conditioning and Refrigeration
Field Service.

{f} Where used on systems designed for natural gas, copper
tubing shall be internally tinned.

{g} Seamless brass tubing shall be composed of not more than
75 percent copper (cartridge brass 70 percent).

{h} Seamless brass tubing shall have a minimum thickness of
0.76 mm (0.030 in.).

{i} Steel tubing shall be constructed in accordance with ASTM
A 539, Standard Specifications for Electric-Resistance Welded
Coiled Steel Tubing for Gas and Fuel Oil Lines.

{j} Steel tubing shall be externally corrosion-protected.

{k} Flexible nonmetallic tubing or hose shall be either listed
and used with listed fittings or part of a listed assembly.

[Scott S.]

I agree with Joe. don't mess with gas. the code here in Canada is you can only have one conection per appliance inside the trailer. I paid $250, had them all replaced and I feel great about it.

[Loren G. Hedahl]

Hmmmm!

I might be completely out to lunch but it seems like common sense is in short supply (and probably against the law too). After all, the pressure we are dealing with is less than 1 psi.

Garden variety air compressor hose is rated for 250 psi and is oil/gas resistant. It is also priced at about 20 bucks for a 50 ft length.

Anyhow. I know of someone ( not mentioning who) who upgraded his Scamp from the stiff, old, corroded copper to nice flexible rubber about ten years ago. He even installed a propane fireplace in his Scamp using the same method. His Scamp also rides on el cheapo p-metric tires. Poor fellow is obvious a driveling idiot to have done that but, you know, it's hard to argue with success. :>)

[Dave Bese]

Well all the codes are meant for construction and industry to reduce liability and to keep fly-by-night operations out of the mix. What we choose to do with our personal property and lives . . .well, sometimes what works works just fine. We can do what we wish; just be careful with those wishes.

[Roy in TO]

I'm interested to know more about how Propane (C₃H₁₀) and copper (Cu) can make hydrogen sulphide (H₂S). Is there some residual sulphur from the smelting process or some not refined out of the propane? That sounds not right from a chemistry standpoint.

Hydrogen sulphide (H₂S) is a naturally occuring in natural gas and propane may be refine out of natural gas. http://www.naturalgas.org/overview/background.asp

Propane has no color, taste or smell in its natural state. To warn users of a leak, propane is odorized with ethyl mercaptan (C2H6S), also known as ethanethiol.

My guess would be poor refinement in the first place or some reaction with the mercaptan.