How to run Propane Lines?

[frey2]

What are the standards?

What materials; steel, copper, brass?

Flared fittings all the way or mix and match with pipe tread?

I've got to run propane from my two tanks on the outside to a stove top, refridgerator, and an outdoor grill.[/img]

[Ryan Grimm]

There are two main systems for propane lines, copper and black iron pipe. There are stainless piping systems that are available, but these MUST be installed by a licensed plumber, and at any rate I do NOT know if they are listed for RV installations.

Both copper and black iron have their advantages and disadvantages.

Copper is amazingly flexible, relatively cheap, easy to cut and splice, add tees or cap off dead ends.

Black iron is heavier, rigid, requires more expensive tools to cut/thread/install, and is sometimes difficult to get cut to an exact length for a small space. Plus, I need expensive unions to break long runs into managable lengths.
Having said that, I like black iron for exposed runs under vehicles, as the strength and rigidity can't be excelled. It can easily span the distance from frame rib-to-rib without sagging. I JUST make sure it's properly attached, with insulated hangers (to prevent chafing/rattling).

Inside a vehicle, I use copper for it's adaptability. Simple flare fittings are an inexpensive way of making connections, and the only tools I need are a GOOD tubing cutter/reamer (with a SHARP wheel, natch!), and a flaring tool kit.

NOTE: I do NOT use compression fittings for copper! I use ONLY flare fittings, properly installed! Compression fittings can NOT guarantee a tight leakproof seal to my way of thinking.
Copper's flexibility serves me well for snaking it into cabinets and around corners, HOWEVER it has to be supported over any distance or it will sag, and may vibrate loose or fatigue fracture. I HIGHLY recommend using rubber/plastic grommets at every hole it passes through, even through wood, and ESPECIALLY through metal holes like in floors or bulkheads.

Another consideration is SIZING. The CAPACITY of the tube/pipe determines the size of the appliance(s) downstream, and vice-versa.
I know what I want to install, FIRST. THEN I run a larger main supply tube down the vehicle length, branching off (WITH A GAS-RATED SHUTOFF!) at each location.

Tube/pipe sizes can be determined by your local LP supplier. I ask them about what size tube/pipe I should run for each appliance, and for all the appliances as a whole.

Do-it-yourself books carry a lot of info on making up copper tube connections, and some iron pipe info.

NOTE: When making black iron pipe connections, I use the proper GAS-RATED thread sealant ONLY on the outside of the pipe threads, NOT on the inside of the pipe fitting threads. The pipe dope will ooze into the pipe if I coat the inside threads, and will eventually break off and make it's way into the appliance I'm using, making for a VERY frustrating disassembly and cleaning job.

NOTE: when making a long run, I add a small vertical 'drop' for debris and moisture to fall into NUST before it gets to the appliance. You'll see what I mean when you look at the supply line for your home water heater or furnace; there is a tee and a capped section that is there JUST to collect crap and prevent system clogging.

NOTE: I DO NOT use galvanised pipe for a gas system, it is not rated for gas retention. If I need rust resistance, I paint the exposed piping after thoroughly cleaning it! I use a good degreaser, followed by a good primer, and two or more THIN coats of paint.
POR15 is an excellent base coat for the pipes.
Cold galvy spray may also work in some situations.

NOTE: I ALWAYS check my connections for leaks, using compressed air instead of gas. Home centers and hardware/plumbing supply places sell small bottles of joint testing fluid, I smear it on joints and pressurize my system to test.

IIRC, most LP systems are less than ten (10) PSI downstream of the regulator(s), check with your LP guy for more specific info for your setup.
If I need to pressurize the system with air, I just put an adapter on the pipe that allows hooking a bicycle pump to the system.
BE CAREFUL!!! DO NOT PRESSURIZE THE SYSTEM WHEN HOOKED UP TO THE APPLIANCES! YOU CAN RUIN THEM WITH HIGH PRESSURE!
Instead, I cap off the fitting (appliance) ends before testing the system.
THEN I install the appliances after testing the main pipes, and check those new connections with the leak finder fluid while under gas pressure.

NOTE: when I do an appliance installation, I always tape a spare tube/pipe cap next to EACH appliance end connction. That way if I need to pull an appliance in the field, I can shut off AND cap the connection for safety's sake....the part I need is already there ready for installation.
Cheap insurance.

NOTE: I recommend you have a Licensed LP installer inspect your system before gassing it up for the first time. A little insurance in the form of an expert's attention can save your RV and your lives.

[Ryan Grimm]

Oh BTW, I believe there are quick-disconnect fittings available for exterior appliance (like grills) use, you'll have to haunt plumbing supply houses (and maybe some RV shops, I don't know) to find them.

Good luck

[vonslatt]

What about plastic? When they replaced the natural gas main in front of our house a few years ago I was surprised that the 12" main and the house runners were all plastic.

Are there plastic systems for propane?

[Ryan Grimm]

Sorry to get back so late

No, there are NO plastic gas lines for residential/do-it-yourselfer use. Tools and materials are far too specialized for Average Joe to use.

[SeanF]

Good stuff Ryan; thank you.

Sean

[Ryan Grimm]

Just found out there are quick-disconnect fittings to use for external camp stoves, grills etc.

Try the local BBQ grill sales places and suppliers, they should have 'em.

[fankhaj1]

Nice work Ryan - thank you for taking the time to do this!

[Ryan Grimm]

I've found Lowe's has gas valves, down to 3/8th inch pipe size.
You might find smaller (1/4, 1/8th inch) in a GOOD hardware store, and there's always the plumbing supply places........

Ace Hardware in Hudson MA supplied me with some 1/4 inch gas shutoffs that I used for my chuck wagon.

Gas shutoffs will be either pipe threaded or set up for flare fittings.

[Les Lampman]

There is another alternative as well. I'm in the marine industry and am involved in outfitting a lot of custom cruising boats. Due to the harsh marine environment and the constant movement of boats the most common propane lines aboard are hoses which are specifically made for the application with swaged ends. Your choice of which system to use for installation of a propane system will be influenced quite a lot by cost of materials and the layout of your bus and how many propane appliances you're supplying.

In my bus I supply three appliances; the stove/oven, the water heater and a Dickenson Marine stainless vented (direct-air) wall mounted fireplace (heater). Like BruinGilda and many others I am using portable propane bottles mounted in a compartment under the bus to facilitate refilling without having to move the bus to the propane station. I have a manifold just downline of the regulator under the bus to which each of the individual hoses connects. Then there is a single continuous run of hose from the manifold to each appliance. Where the hose enters the bus through the floor there is a purpose built bulkhead fitting (the hose slides through and then a plastic nut is tightened which compresses multiple fingers against a rubber grommet to make a tight seal) to protect the hose and in this case keep critters, spray, fumes, etc outside. The hose then connects directly to the appliance.

What I like about this system is that I have only one connection inside the bus for each appliance (and specifically right at the appliance) and it's a factory-made swaged fitting of high quality. The connections for the multiple runs are all made under the bus near the propane compartment at the manifold; they should be vapor-tight and sealed well but if they do leak it won't be inside the bus. Shut off valves can be installed at the manifold to facilitate shutting off an individual appliance.

Several approaches to installing propane systems are viable; this isn't meant to suggest that this method is "the best". I only offer it as an alternative since many folks are not aware it exits. Outlets like West Marine and others carry the hoses. The system is used almost exclusively in yachts today and is designed to withstand the rigors of world cruising sailboats operating in tropical (read harsh) climates.

[the_experience03]

Back when I worked for Nortemp Heating and Cooling we used lots of interesting new products. My favorite was the Pro-Press, a type of crimp on copper water line fitting that was building code approved. The added expense of the fittings was easily offset by the reduced labor times. Of course that is of little use in a bus...

Another product we used A LOT was called Gas-Tite. It was a stainless steel flexible tube with a rubber coating on it. We used it all the time for runs for fireplaces, furnaces, boilers, etc. We simply tapped into the existing black iron supply lines from the outside. The produce was easily cut with a regular tubing cutter. It then used a compression fitting of sorts to go back to whatever size NPT thread you needed. I doubt the stuff is listed for RV use, but most of what we use isn't.

I know we had both regular and underground rated stuff and IIRC it all came with a 25 year warranty so there's no fears about it not holding up. If I could remember how much it cost I would gladly tell you, but I don't unfortunately. If I get a chance I will go and find out. I know it was expensive, but it was high quality and easy to work with. Just another idea I thought I'd throw out there.

[bdavis441]

I have also used the gas-tite tubing. It works great and very easy to install. There are a couple of other brand names of this type of product, but the fittings are specific to the brand, be aware of this. There is a version of this available at Lowes, but I'm not sure of the brand name.

[Les Lampman]

I want to clarify that in my previous post I was talking about a very specific type of hose. This is rubber hose with a stainless steel braid and a fiber external wrap (it really just looks like a hunk of black hose in your hands). It's tough stuff and it's designed as gas supply hose and meant to run wherever it needs to go in a boat and do it safely. A boat hull is a closed space and propane being heavier than air it makes a perfect container for leaking propane; that's NOT a good thing and the Coast Guard is very picky about how systems ought to be installed. One manufacturer of this product is Trident and it carries a UL listing. Sure Marine is Seattle is another supplier and they can supply custom length hoses with the blukhead fttings pre-installed.

I don't know that other stuff won't work and I'm not personally familair with every type of flexible hose available for propane systems. There may be lots of products that would fit the need but I would urge extreme caution. I'm using the marine hose because I know it's rated for that use and was specifically designed to last in an environment with constant movement. If you find something different just make sure it's rugged enough to withstand our busses sometimes not-so-gentle ride (at least mine is that way!).

EDIT: I did and Internet search for the Gastite product; it's flexible stainless tubing with a polyethylene coating with an approved working pressure of 5 PSI and a jacket melting temperature of 350 degrees. It has a minimum burst pressure of 1500 psi. Code approvals are for residential and commercial applications. To comply with codes it must be installed by a Gastite certified technician (what's up with that?).

This looks like good stuff and far better then what's in my old Class "C" motorhome. I'd personally tend to stay with the marine hose though because it's made for a mobile environment and it doesn't require any expertise on the part the installer (me!).

[eggman]

Gastite and Tracpipe both use proprietary fittings. If you get them confused, its not a problem, because they arent even close to fitting the other brand. Both of them run about 2.50 per foot and fittings are about $10-15 each for the 1/2" size. Very easy to work with and quick to make the runs. Certification tests for gastite and tracpipe are about 30 questions long and can be completed in about 15 to 20 minutes. Its not rocket science. To be able to use either of them on a bus, the bare ends would have to be covered in their respective yellow tape to help fight any possibility of corrosion when ran under the bus.

For the record, I do like the idea of the individual propane certified hoses ran from the manifold to each appliance. However, I think that the shutoff valves should be a bit easier to get to than having to leave the bus and get under it to shut them off.

My $0.02

[Ryan Grimm]

You make my point for me, both for Gastite and Tracpipe....black iron and copper are cheaper, and still standard practice with 'conventional' RVs, and very adaptable, and universally available.
Thanks for posting the alternatives....more info is always useful.

I'm sure I'd love the Marine fittings, but the expense is something I could use the extra $$ for stuff like wine and condoms, or maybe diesel.
Warning; do not mix condoms and diesel. Tragedy will result.

[Zcommanager]

Les, I'm pretty intrigued by your marine gas line. They seem pretty indestructible to me, but I'm just wondering, are you able to run the Trident hose from the exterior propane tanks to the inside of the bus, or should one still run black iron on the exterior and pick up with the Trident on the inside?

Also, I have noticed that some of you guys are using what looks to be standard 20 lb. propane tanks on your buses versus the larger stationary propane tanks. Being new to "self bus conversion," and trying to learn as much as possible without sounding too stupid , I'm wondering is it more economical to go this route, or are most of you using these smaller tanks for ease of swapping out an empty for a full tank? And one last question...I think... How long do the smaller tanks generally last you?

Thanks for the great info/ help and for not laughing too loudly at my naivite.

[John]

I recently completed propane installation of some appliances from a main tank. I used black iron pipe under the bus to where my appliances where, then used the standard appliance flex-hose. However, after looking things over, I noticed that the flex-hose clearly says it is not intended for use in a moving vehicle including rvs.

Do you guys think this is for liability reasons, or is there a serious vibration concern? Should I rip out the hoses and run copper or this marine hose mentioned earlier in this thread? I like the idea of being able to remove an appliance and then detach the propane line (i.e. it is hard to access my stove from the back without moving it. Luckily I don't have to move anywhere for a while so I can leave them in for now, but I need to figure out what to do safely for when I do start moving again.

[John]

Originally Posted by Smitty

Would be a tough call John. You could keep a spray bottle of soapy water handy & leak check it every so often (which wouldn't be a bad idea on any gas piping system) I was always the "if it ain't broke, don't fix it" types and ran miles of black iron pipe over the years. I did use alittle copper for LP applications, but even got away from that when the freed-up natural gas decades ago. I just made it a habit to always run black pipe in the event they ran natural gas, and the house was converted, it was properly piped (natural gas will eat copper tubing & is against code) so it was just a matter of converting the appliances.

I've also repaired copper lines on RVs/Trailers which cracked from road vibration. Does your black pipe up through the floor to a gas stop, then switch to the flex connector? What material is the flex connector (stainless or brass), and you didn't use the flex connector to "pass-thru" the floor or wall did you?

I won't even be running my gas line under the bus, it will be inside tucked into the corner where the floor meets the wall.

Smitty

The black pipe goes through to a gas shutoff then up through the floor, once on the other side it switches to a BrassCraft "coated stainless steel gas connector". I had to use copper at each appliance as they all came with flare fittings, but only about 2 to 6 inches worth. The reason I put the gas stop under is because it is a lot easier to get to than inside or with the appliance. It is still within 3 feet of the appliance (as per code).

[John]

Yep, I put a 5" drip pipe fairly close to the tank. It's the lowest point in the system and there are no other local minimums anywhere else (that would act as a sink drain trap for propane moisture) That's a good idea about not bending near the ends, I'll take a look at my lines.

I had someone help me who knew how to install propane in a household. So things like drip pipe's, pipe-tape on all non-compression non-flare fittings, etc...

Thanks for going to the extra length of looking up the product, and I'm very much looking forward to bacon and eggs. I've been cooking on my wood stove, but mainly boiling water or roasting.

[Seeria]

"Where the hose enters the bus through the floor there is a purpose built bulkhead fitting (the hose slides through and then a plastic nut is tightened which compresses multiple fingers against a rubber grommet to make a tight seal) to protect the hose and in this case keep critters, spray, fumes, etc outside." report.php?f=8&p=7704

I am interested in this gadget. Is there a name for this?
I am not installing appliances in the bus but will have a propane heater with the line run up through the floor. Would like to find a way to protect the $50 hose from rubbing on the floor as well as keeping bugs and critters from making use of the hole in the floor.