Gas line under tear?

[jandbsteardrop]

Hi,

This is my first post. The wife and I are going to be building our very first teardrop. We're super excited and look forward to the journey. So glad to have found this site!

Quick question....is it safe to run the gas line for propane from the tongue, under the tear to the stove that will be in the galley? What do people typically do here? I think we're going to have the propane on the tongue...so wanted to know if it's a good idea to run the line underneath the tear or what is the most common practice? Do you take the propane off the tongue and bring to the back of the tear?

We're just getting started on this journey so thanks for your help!

[bobhenry]

When I built the chuckwagon I ran 1/2" black pipe front to back at the front I tied it into the delivery hose with the proper fittings and ran a flexible gas line to the 3 burner stove/oven. I made the holes thru the floor tight even for the pipe and once the elbows were installed and close nipples extended thru the floor the next fitting clamped the pipe tight to the floor.

[jandbsteardrop]

Excellent, thank you! That sounds like a good idea. Do you have pictures of this/your build...let me see if I can find it...thanks!

[Dale M.]

Yes.... That is preferred way.... Propane is a heavier than air gas, if it leaks it finds low spots and it pools.... Inside trailer floor "may" be a low spot for it to pool.... NOT GOOD..... Under chassis if it does leak it will dissipate and dilute into surrounding air and not pool and not be a "hazard" but do not misunderstand a leak is always a hazard...

Dale

[matthewp]

I have done the same thing. I ran my extension hose through a 2" X 2" steel square tube underneath the frame to protect it (mind you, I am building an off-road trailer, but I hope that adds to your ideas).

[treemaker]

3/8" copper tube is ok for propane but it must be protected from damage by road trash.

[Shadow Catcher]

I changed from steel to copper. Do make sure you have you have fittings for propane/gas not water. Check for leaks!!!

[Treeview]

After I get the new tail lights/trailer plug wired I'm going to hang the underbody LP tank. The fitting on it is flared. the lines under the camper that I got the furnace from were copper.

Am I missing something?

What is the difference between water and gas fittings? In the past I've always used single flare fittings for gas.

I've done my share of flaring, I have the tools. Also a double-flaring kit for making brake lines.

If i were inclined I might run black iron, I've got the dies to make my own lengths. Is there a compelling reason to use black iron?

Tom

[MtnDon]

FWIW, single flare copper is not approved by the RVIA. RVIA rules state double flares are needed. Single flare is good for home residential use. Single flare was used for many years on RV's, but apparently there were some failures due to motion. I don't know how critical that is. We had a class C for 15 years that was single flared and never had any problems. The big No-No is to use compression fittings that one might use on water piping for example.

I run black iron on homes because size for size it is cheaper than copper. I never thought of using it for mobile installation. I wonder if there are any studies on iron in a moving and therefore jiggling, bumping environment?

[eamarquardt]

Personally I think that a good flexible hose would be far superior to copper and perhaps black iron.

http://www.fireboy-xintex.com/propane_d ... html#Hoses

http://www.westmarine.com/webapp/wcs/st ... qQKWPRDufY

http://www.westmarine.com/webapp/wcs/st ... qQKQfRDufZ

There are no second chances on a boat and if these hoses are suitable for use on boats (where propane can't escape) they ought to suffice for a trailer.

If one is worried about chafe/damage there are any number of ways to provide extra protection to the hose and fittings.

I'd be concerned that, over time, a copper line might flex at a connection, fatigue, and fail.

Just my two scents.

Cheers,

Gus

[RandyG]

I have also questioned how to run the LP line to the back. I might run flex hose through a mounted pvc pipe with small holes drilled into the bottom to let any leaked gas out. A solid piece could capture gas and turn deadly if it caught a spark.
I dont mean to take over the thread but I have another option but have a question about it. At work I can make a stainless line with single flares, would SS be ok for LP?

[Larry C]

Am I missing something?
What is the difference between water and gas fittings? In the past I've always used single flare fittings for gas.
Tom

In northern climes especially, the machined 45 degree (long) flare nuts tend to crack from frost. The short (forged) nuts are less prone to frost cracking. I would check to see what your state DOT requires for conveying LPG on RV's in your state, and federal DOT as well. Over the road requirements differ from state to state, as does the federal regs regarding LPG transport.

As I have stated previously, LPG hoses are normally intentionally perforated to let the gas that migrates through the inner tube to dissipate through the cover to the atmosphere. If there were no perforations in the cover, the gas would accumulate as bubbles under the hose cover...not good!

All the LPG hoses I deal with and know of, are the type having pin pricked covers, and are ONLY suitable for outdoor applications, not suitable for indoor confined areas. There are probably some hoses suitable for confined areas such as Teflon tube w/stainless steel over braid, or welded convoluted stainless steel tube w/stainless steel over braid or some other barrier tube hose. Being a hose applications specialist I don't know of a rubber LPG hose that I would trust in a confined teardrop galley. However, there may be some I am unaware of.

Black iron pipe, and copper tubing would seem to be prone to vibration cracking on a trailer, but IMO/ are still probably better than hose. Just last week where I work we decided to discard several hundred feet of LPG hose that was over 8 years old, sizes from 1/4" - 1-1/2" Hose has a shelf life, and an even shorter service life.

Do your homework... find out the current regulations/requirements for LPG use on RV's in your state as well as the federal DOT requirements.

[Treeview]

I've been reading and getting a little clarity.

One bit of clarity is that the rubberized hose is made with layers of materials. The inner is NOT made to leak or have pinholes. Every layer out from this is made to leak so that the gas can dissipate and not cause a bubble in the materials.

This is an old thread so some of the links might be dead, I just found it and haven't gone down the rabbit hole yet.

http://sierranevadaairstreams.org/snuze/?p=619

I'd like to read chapter and verse from RVIA about double flaring. So far ALL that I've read, except in this thread, is that single flares are OK.

My project research is always way ahead of the build. This allows me plenty of time to get clarity.

Tom

[MtnDon]

I wish I could point to an online resource about the RVIA and double flaring on copper propane lines. I can't though. I received my information about double flares and the RVIA from an RV technician. He was a business acquaintance in an unrelated field. He was not selling me any goods or services. I have no reason to doubt what he told me, just can't back it up with a gold plated reference. Google comes up with a reference or two in other forum threads and a blog. Some of the posters claim to be RV techs. I can't prove it one way or another.

OTOH, RV's were manufactured for decades using single flare copper tubing connections for their propane systems. All the old ones we owned never had any issues associated with the tubing.

I'm thinking this may be one of those things where the new "thing" is slightly better than the old "thing" in some cases and may save people from troubles / injuries, etc. We run into changes or evolutions in the residential building codes that do not always make everybody more safe. However, in general codes are a good guide to what is safe. I do wish I could find a solid reference to the RV and double flare issue though.

The RV tech acquaintance has passed on to another dimension so I can't check with him.

[Treeview]

Just a little more reading...I pay attention to the date on posts because standards and 'tribal knowledge' change over time.

This thread is from '08

my mistake that double roll flares are required by code. they are not. most manufacturers use double roll flares because the initial pressure test for a lp system is five times higher than operating pressure. and maybe they just give a better seal. there has to be a good reason to use a technique that takes twice as long to do.
all the rvs ive worked on have had double roll flares from the mfg. whenever i repair a copper line, i use a double roll flare.
that is not to say that single flares dont work. a lot of aftermarket installers use single flare with great success.

From this thread:

http://www.rv.net/Forum/index.cfm/fuseaction/thread/tid/22032781/srt/pa/pging/1/page/3.cfm

There may be more...like U2, 'I still haven't found what I'm looking for'

[The above portion of my response was written at about 5pm. It's now 7:30pm and I have more info that follows]

If you go here:

http://www.nfpa.org/catalog/services/onlinepreview/online_preview_document.asp?id=119211#

You can register and read the 2011 NFPA-1192 Standard.

I made a screen capture [Very easy on a Mac---Command/Shift/4---and a cross-hair comes up. The image is saved as a jpeg] The screen capture is in my Gallery:

http://www.tnttt.com/gallery/image_page.php?album_id=2415&image_id=115080

So...now, I feel comfortable using single flare connections.

Tom


Tom