Flex line for propane stove.

[bobhenry]

This has been a real timely post for me. I was a couple hours away from going next door to the plumbing shop and purchasing what I needed to plumb the chuck wagon. I had scrounged a charbroil regulator and hose assembly off of a tossed out propane grill and was simply going to adapt it to the 1/2" black pipe that runs to the rear of the trailer to the stove but I guess I may need to either hard plumb it or go spend sone money at the propane joint.

[eamarquardt]

For the sake of safety.........


If you use Hydraulic hose which has a Nitrile tube the propane will leak through the tube and become trapped under the non pin pricked cover. This will create little bubbles of gas under the cover.

The hose used on forklifts are rated at 350PSI Working Pressure (5x1 safety factor) as are most all Propane hoses. The forklift hose has a stainless steel braid to add extra strength if the hose catches on something and for longevity from the weather.

It would be a great choice for a Teardrop. However, It will, as designed, allow the Propane to seep through the cover, so it must only be used outdoors in a well ventilated area. (UL21) Don't use Propane hose in a confined area!!!!

FYI: I run a hose shop and have been building, specing, testing, and selling hose for 40+ years. I am BCHD certified hose specialist. Our shop builds and hydro static tests/certifies thousands of Propane per year. We hydro test ALL Propane hoses to RMA specs of 2 times the WP (700PSI) for 10 minutes.

Larry C

I have learned not to argue with folks that know more than I (and even not to argue with "Big" Guy (Teardrops for Vets), even though I sometimes doubt his "facts" as he goes for the jugular (twice on each side) and won't let me know when I'VE WON the argument). Your explanation that propane hoses are designed to leak baffles me and seems to defy "common sense" that hoses carrying flamable gasses should be "gas tight". All serious leak testing is done with helium as it is the smallest element in its natural state (one helium atom even though hydrogen is smaller but hydrogen is actually two hydrogen atoms in a molecule). Propane is a big molecule (compared to a a water molecule) and it's surprising it gets through a rubber hose. I called a big hose shop and they confirmed your statements. WIERD. Learned something today. You'd think with modern materials they could make a hose that doesn't leak!

Cheers,

Gus

[Dale M.]

LGP hoses are made up of multiple layers of different materials...

The internal layer that is exposed to the LPG is in all practical purposes and if in good integrity is gas tight. AS IT SHOULD BE..

Outside of that you may have many layers of rubber or synthetic substances and fabric weaves.... On outside you have the outer coating, I would guess its called a dress coating.... This outer coating is where the micro perforations are.... Other wise if the inner passage or tube were to leak and it would just blow up the outer covering like a big balloon till it burst. The micro perforations in outer coating allow the propane to escape from under OUTER coating if there is a leak in inner wall.. This also allows the "ODOR" of propane to become apparent in area as a warning there is a problem....

But then I may be full of crap .....

Dale

[dh]

So, exactly how mutch propane can be expected to seep out of the hose? If it was a great amount you would be able to smell it.

[Dale M.]

So, exactly how mutch propane can be expected to seep out of the hose? If it was a great amount you would be able to smell it.

None..... It only happens if there is a structural defect of inner wall of hose....

Dale

[Larry C]

So, exactly how mutch propane can be expected to seep out of the hose? If it was a great amount you would be able to smell it.

None..... It only happens if there is a structural defect of inner wall of hose....

Dale

Dale, From my experience, MANY is more accurate. We hydro static test each and every LPG assembly we build, not so much to see if it leaks, we already know most will leak some propane, that's why the cover is pin pricked.

We hydro static pressure test to see if the hose, and mostly our fitting installation will withstand 2 times the working pressure, so we can supply test documentation. We mark the crimped fitting location, and check for any movement during the test. If an end blows off, that's a lot more serious than a tiny leak through the cover.
We experience approx. a 5% failure rate during hydro static pressure testing where water squirts from a bunch of holes like a law sprinkler! Not everybody tests their LPG assemblies. Most Non DOT hoses are probably not tested!

What everyone needs to understand is LPG flexible hose connections are designed for well ventilated areas where tiny propane leaks are not normally an issue. It's when this hose is used indoors or other confined area where the buildup of gas can be a problem. Indoor use requires hard plumbing, not hose!!

DH, To answer your question: I would assume any rubber (non barrier) hose will "probably" leak some propane, is this a problem? Probably not, UNLESS YOU KEEP THE PROPANE FILLED HOSE IN A CONFINED AREA.

There are probably hoses such as Teflon with SS overbraid or convoluted SS with SS overbraid that would be fine in confined ares, but may be cost prohibitive, and not meet DOT requirements.

The bottom line... Be safe, be safe, be safe... and consult your State and the Federal DOT for specific requirements concerning Propane connections and transported on public highways. Use hard plumbing, either black iron, copper tubing or what ever meets the requirements, and use the flexible (hose) connection only to connect to the appliance using appropriate methods, especially keeping the hose in ONLY well ventilated areas.

Safety Please......

Larry C.

[dh]

Heres what I'm thinking, the only thing I'm running on propane is the stove. I can't close the hatch if its extended, and will set the countertop on fire if I run it retracted. So, if I simply turn off the gas at the bottle and open the stove valves and bleed off any pressure from the system before retracting, I should be safe. Any flaws in this theory?

[Larry C]

Heres what I'm thinking, the only thing I'm running on propane is the stove. I can't close the hatch if its extended, and will set the countertop on fire if I run it retracted. So, if I simply turn off the gas at the bottle and open the stove valves and bleed off any pressure from the system before retracting, I should be safe. Any flaws in this theory?

That should work fine. It's a good practice to shut off the tank when not in use anyway. I assume your using hard plumbing under the trailer (or should be), and are using the hose for the flexible connection to the stove. I would install a 1/4 turn shut off valve where the hard plumbing meets the hose.
also, I like the propane quick couplers that Slow mentioned.

If you just want to be able to close your hatch, just shut off the 1/4 turn valve, bleed or burn off the gas left in the hose, but while sleeping or towing shut of the tank and bleed off everything.

That's just my personal opinion, and it's what I have practiced in the past. Others may have a different opinion. I tend to be over cautious when it comes to something that can kill me


Larry C

[madjack]

...as a former licensed gas fitter, plumber and??? I would like to doubly endorse everything Larry has said...it only takes an extra minute to do things safely but it can take a lifetime to get over doing it wrong!!!!!!
madjack

p.s. ...thanks Larry(and others) for all the good info, I think this one should be a sticky!!!!..................mj

[bdosborn]

So what kind of hose do you use for gas appliances inside a trailer?

Bruce

[Larry C]

So what kind of hose do you use for gas appliances inside a trailer?

Bruce

Bruce,
That's a very good question! There are hoses that have a true barrier from gasses escaping. One of the most common ones is the hose for Freon, which tends to leak easily. However, I don't know of a barrier hose for LPG. All the LPG hoses I am familiar with are designed for use in well ventilated areas because these hoses can and do leak gas.

Indecently, if the LPG hose I am describing is used for natural gas, it's working pressure rating goes from the 350PSI WP rating for LPG to 1 PSI WP for natural gas because the natural gas molecule is much smaller than the LPG molecule.

Personally, I wouldn't use any hose inside a a camper unless it was tested and certified for that purpose.

There has to be some standards published for what is required by DOT or other governing body for Rec Vehicles. I am not familiar with what propane hose (if any) are used (inside) on travel trailers or Motorhomes. My experience is more related to industrial applications. Does anyone have such a vehicle? if you can get all the info off a hose's layline I will try to research the standards required.

I used to have a pop-up camper with a propane hose that connected to stove on the inside. The hose retracted by pushing it into the counter top, and had a cover over it. It went into a sealed cavity that was vented to the outside. That camper was hard plumbed with copper tubing with 3/8" 45 degree flare fittings.

I think this discussion has lead to many of us wondering what we should actually be using for connecting propane appliances especially inside our Teardrop builds. If there any TD manufactures listening, please chime in, this is an important safety issue.

Larry C

[madjack]

I went looking for some spec from RVIA and could only find generalities and the offer to sell me a book of standards...here is what I did find(basically useless for our purposes).................
madjack

Fuel Systems and Equipment as specified in ANSI/NFPA 1192 Standard on RV’s.

Venting requirements for propane appliances are specified where necessary.
Propane piping sizes are required to ensure a propane supply that provides for proper appliance performance.
Over fill protection devices (OPD) are required on all installed propane containers.
Propane line routing and accessibility - all joints in propane lines must be accessible for periodic leak testing and repair. Lines may not be installed in spaces where a nail or screw could pierce the line.
Fuel burning appliances must be listed for RV use and labeled by a nationally recognized testing agency that has found the product to be suitable for its intended use.
Sealed combustion and direct venting to the outside is required for all propane appliances, except for gas ranges, to provide for a complete separation of the combustion chamber from the interior atmosphere.
Each propane system must be tested upon final assembly to determine proper leak-free performance.

[dh]

When I was rummaging through an old wreck of a camper looking for parts two years ago I found remnants of copper flex line comming off the hard plumbing in the hole where the stove used to be. Is this what they use?

[dh]

Larry, I am running galvanized pipe under the trailer and up into the gally, and up front I have a POL directly into a single stage regulator, then it turns down with a hydraulic rated street elbow into a 24'' hose that mates with the hard plumbing in front of the tongue box. Any flaws there? I was told by a local RV guy and an orange vested man that galvanized was ok, but have recently heard differently.

[madjack]

dh, black pipe was always the preferred product because(supposedly) zinc can flake off of galvanized and stop up the orifices of your appliances...some codes say yay and some say nay...in my experience, I have never come across an orifice stopped up from zinc flakes..............
madjack