Gas line under tear?

[Larry C]

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.
Tom

Hi Tom,
To clarify....(not looking for an argument) I did NOT state that the hose inner tube is intentionally made to leak or have pinholes. What I did say was the gas that MIGRATES through the hose tube must have a path to atmosphere thus the pin pricked hose COVER. Hose nomenclature: Tube/reinforcement/cover. Many rubber hoses rated for gases, including air hose have perforated covers.

An example of how much gas can actually get through the hose is that exact same LPG hose that is rated at 350 PSI working pressure (depending on fitting attachment method) is ONLY rated for 1 PSI, yes that's ONE PSI when used with natural gas. The nat-gas molecule is much smaller than Propane/Butane, thus the lower maximum allowable working pressure of 1 PSI!! The inner tube of rubber hose can indeed leak gasses, not intentionally, but it's the nature of rubber hose trying to contain gasses such as LPG. This leaking gas must be allowed to dissipate, not accumulate!

All LPG hoses I work with are hydro static tested to 2 times the working pressure according to the RMA The 350 PSI max WP hose is tested at 2 times MWP (700 PSI), and held for 5 minutes. In my experience, about 3% of the tested hoses fail, usually with the hydro test water exiting the hose cover like a lawn sprinkler. This hose has a 5 to 1 safety factor meaning the theoretical burst pressure is 1750 PSI!!! Yet some of these hoses leak profusely which is ONLY found during testing.

The hoses you are probably using are normally only seeing very low PSI after the regulator, assuming the regulator wasn't removed because it failed, and it was thought to be OK to go without it. These consumer level hoses are not normally tested, and are INTENDED for outdoor use only. If one leaks/fails in an outdoor situation, no big deal. However, what if it's a supply line for a propane heater or a cook stove in a confined trailer?

My concern is that a fellow teardrop/tiny travel trailer builder will assume they can just use any hose rated for LPG even if it's only intended for open air outdoor only use, not for confined areas where the heavier than air LPG can accumulate.
The bottom line: Just make sure the hose you want to use was designed for your intended use.... and remember hose has a working life, and should be replaced periodically.
******BE SAFE******

[Treeview]

HI Larry,

Oh, of course, no arguing or challenging meant on my part either One reason that I like this forum so much is that the participants always attempt to move forward and help each other. There are so few examples of bickering and arguing!

I'm trying to have my own clarity about the installation. As much as possible I want to build according to current practices.

I'm an arborist and I've been active on our ANSI Z133 standard for about 15 years. Most of that time as a voting member. Having an industry consensus standard is a challenge. Something that people don't understand is that a 'standard' is not necessarily 'the law'. In the workplace, in the US, the law is OSHA. The way that I explain the difference is that by not following OSHA you're going to deal with the equal of a Federal Marshall. If you don't follow a standard you're going to be dealing with your coach. Of course, the coach can have a heavy effect on what happens too. In a law suit the word of the coach can potentially have the same weight as the Federal Marshall. In our case, if any installation of gas lines were done for hire rather than personal, recreational, use there could be legal ramifications if standards aren't followed. Not following current standards or 'tribal knowledge' would be immoral in my opinion.

The time that I've spend researching this topic today has brought a lot of clarity to my build. The catch is that by tomorrow I'll likely have accepted a new job. That will mean a move from Asheville to Minneapolis. All ToyBox building will have a Stop Order unless it relates to making the move easier. Hmmm...having a furnace in a camper in Minnesota seems easy to justify though...

Tom

[MtnDon]

One of the things about the rules we have to deal with, like those in the NFPA, is that it is virtually impossible to read the exact text that pertains to the situation without buying the code book. That was the case with the IRC (International Residential Code... the building code for one & two family residences adopted by 49 states). It has been available online for a few years now. But it does not seem the RVIA has anything online other than a place to buy the book. Ditto the NFPA and NEC. I just find it frustrating. I understand they make money from the sales but I also feel that if rules are meant to be followed the rules should be freely available.

[Treeview]

But it does not seem the RVIA has anything online ...

Oh, there is...go back to my post, I put in the link for on-line access. It's read-only but all there. I did a screen capture to grab the section that's germaine to our discussion in this thread. I'm guessing there is a way to do screen captures in PC-land...I haven't been there for close to 10 years though

YOur comment about the standards being free is one that I've heard for years. The ANSI Z133 is sold and there are no e-copies like the 1192. The money that is generated covers the costs of renting conference rooms and a day of meals twice a year for the committee members. No committee members get paid a dime out of the money raised though. I pay my own way out of my own pocket. When I was in business it came out of company funds. After I shut down my tree care company the money came out of my paycheck...including travel and lodging. Each meeting costs me about $600 and two days work...which I pay for, gladly, to be part of the safety solution for my profession. Some of the people on the committee are covered by their company and are on salary. Not me though.

Tom

[MtnDon]

Oops. Somehow I missed that. Thank you.