Per-appliance LPG shut-off valves (NFPA1192, & ABYC A-1)

[Jolly Roger bus 223]

if you install a regulator inside at each appliance pay attention to the venting required.
some regulators have a vent limiting device and dont have to be vented outside and some can not use the limiting device and the vent has to be piped outside.
there are several manufacturers around but i use maxitrol second stage and usually Fisher first stage.
i do alot of gas piping at work.
propane and natural gas for commercial HVAC and back up generators.
i have an old out of date pocket manual i keep in my truck called the LP gas mans handbook that will help you size regulators, piping and distances for total BTU and individual BTU.
not RV specific but it could give you more to think about.

 

[ewo1]

When it comes to the science of lp gas, I am clueless... this thread is really starting to share some real good safety info! Stuff I was clueless about!

I got to say thanks to you all who know about this stuff and are sharing!

@Jolly Roger bus 223, since you have the gas install experience, could I persuade you for a basic install diagram, for skoolie installs?

 

[nikitis]

I only know enough to install black pipe from the meter to my house range. I learned from a certified gas installer who was retired similar to Jolly Roger. I wasn't afraid to take it on myself, and He told me everything I needed to know to get "A" job done. More advanced jobs would be out of my capability. I shut the gas off at my meter, added a Tee to it, and ran black pipe through my house through to my range because My electric bill was so high from the electric range, I wanted to switch to gas. And the install by a professional was gonna cost WAAY too much at the time. I was able to do the install at a fraction of the cost, and I had my old retired certified gas installer come check my work after I was done(to be sure), and he said he would of hired me if he was still running a business, but that comment was towards my install quality, not my knowledge of gas.

Many people though seem to know less about gas than electricity overall I find, and I think fear of explosion detours many away from the trade.

 

[Ozbozz57]

@ewo1 So I've asked about the vertical placement of the regulator, and I'm told that todays regulators that's not required. Too many installers needed regulators designed to work horizontally so designs have changed.

However, it is wise to install sediment traps in the event that your propane isn't clean coming out of the tanks. Most propane systems do not have sediment traps in-line, but systems can still benefit from it.View attachment 2389877

This is a picture of one I did in my house. it's simply a Tee with a down pipe into nothing. Any weighted impurities will fall down into the bottom and not go into your appliance. My regulator is also horizontal right behind that wall.

Also when using black pipe for gas I would highly recommend using the yellow pipe dope. The yellow thread wrap stuff doesn't work as well on black pipe I've found. I would wrap it quite well and still get leaks, and I had a retired Gas installer tell me always use the pipe dope with black pipe. Flared connections like the yellow line in the pic above is not supposed to use anything, Just ensure it's a tight snug fit.

When using the yellow pipe dope, it requires 24 hours to cure before pressurizing.

I'm not 100% sure on the regulations for RV setups though, but I thought I remember reading somewhere it's not recommended to use black pipe in mobile vehicles for some reason. I need to look into that. But many RV experts have warned against using it due to movement of the vehicle it can crack couplings.

Nikitis, the "down pipe into nothing" is a drip leg. It is positioned at the end of a horizontal run, just before the pipe goes up into the appliance. It is necessary in a natural gas system because natural gas often has quite a bit of water in it. It's not necessary for propane because propane has no water in it. I did put them in the gas piping for my house, even though I'm on propane, in case the city ever brings natural gas out here.

 

[Ozbozz57]

black pipe and copper are the two NFPA code-compliant options you can choose from for stuff under-the-bus. That's all I've got. And I sincerely appreciate the above advice, @nikitis. Many thanks.

@Kentucky Dreaming, I feel you. We lost our last girl this past year. Think she made it to ~12 (got her at the shelter, where she was supposedly 2, but you never know). Prior to that we had up to 8 dogs at once, most from the same litter, which means the ones who made it to old age all kinda went at the same time. Those were a really rough couple of years.

@desrtdog, tell me about it (lol)! Funny story: The other day, I'm sitting in the living room, and all of a sudden this whiff of "Oh no, not again" comes wafting by. "Baby, Brutus just expressed again"! Turns out he hadn't. Apparently my wife had just opened a bag of shrimp we had delivered! Needless to say, it had gone very, very bad. So if anyone ever asks you to explain what anal gland expression smells like... it's spoiled shrimp. Exactly spoiled shrimp. Disturbingly... spoiled shrimp.

@Ozbozz57, you sure do clean work. Can you elaborate on how that hanger is secured?

Hubbard, I used an old used pipe fitting (flare nipple) as a stand-off spacer to position the pipe hanger clamp at the right height below the floor. It's through-bolted to the flange of the floor "boards" (the steel C-shaped sections that run cross-wise to the frame, forming the floor of the bus body) What ARE those things called?

 

[TheHubbardBus]

if you install a regulator inside at each appliance pay attention to the venting required.
some regulators have a vent limiting device and dont have to be vented outside and some can not use the limiting device and the vent has to be piped outside.
there are several manufacturers around but i use maxitrol second stage and usually Fisher first stage.
i do alot of gas piping at work.
propane and natural gas for commercial HVAC and back up generators.
i have an old out of date pocket manual i keep in my truck called the LP gas mans handbook that will help you size regulators, piping and distances for total BTU and individual BTU.
not RV specific but it could give you more to think about.

Truly appreciate the info, @Jolly Roger bus 223! Looks like the only regulator we'll use will be a 2-stage past the tank (outside). I had already done the calculations a long time ago regarding BTUs, distance to appliances, & pipe ID (I need 1/2"+ ID for our needs). Unfortunately I didn't record the source I used to determine such calculations (d'oh). Those calculations assumed every single gas appliance we own, as well as others not yet purchased (like an outdoor burner for crawfish boils lol), all running at high at the same time, to be on the safe side of overkill.

 

[Bjorkinman]

Okay I'm chiming in. I fitted my whole bus using Pro-Flex, with a shut off valve at each appliance (stove, hot water heater). I have an RV style 20 gallon tank with regulator and shutoff feeding the the Pro-flex lines. This was really easy to install vs. black pipe in my opinion. If you aren't familiar, Pro-Flex is just stainless flexible line wrapped with a yellow covering. So far so good. Also, I turn off the main supply valve at the tank before I drive.

 

[TheHubbardBus]

@Bjorkinman, did you do the whole bus in CSST / Pro-Flex, or just the backbone underneath the bus? The ommission of CSST from RVIA / NFPA1192 / ABYC standards is another one of those "I'd really like to know why" bits. Personally I'm sticking to code so it's out for me, but I know many folks that work with it daily love it. How / did you bond it (electrically)?

 

[Mat7783]

I'm getting real close to starting to implement our propane system. As such, I'm revisiting all the applicable/useful codes. ABYC (boats) is effectively a bit more stringent in some regards, so I'm considering them both together (as I have done with our electric system as well).

Both of these standards apparently require an interior shut-off valve PER APPLIANCE. My question is... why? I get it if the appliances are some distance away from each other, but say you have a range and a heater right next to each other (each well within the acceptable distance from shut-off valve to appliance listed in one or both standards). Wouldn't it make more sense to have a single point (one valve) where gas could potentially leak from, than multiples? Both standards are explicit in this 'one shutoff valve per appliance' mandate, so I figure I'm overlooking the logic in it. I just can't figure out why.

Aside from convenience (being able to shut-off one problematic appliance while keeping the others in play), is there another reason? Could it be because the volume of gas remaining in one appliance after shutting off the valve could feed back into the problematic appliance?

The way I see it, if you were to use 1 valve for an adjacent pair of appliances versus 2, the number of connections would be the same, but you'd consolidate those connections to just one point (which could be exactly where your propane leak sensor is mounted).

FWIW, I'm going to follow code to the letter. But... I really would like to understand the reasoning here. My tentative plan is to co-locate each of these two shut-off valves at a point in-between the two.

EDIT: The more I think about it, the more I'm guessing that the part I just bolded above is why. If you need to shut down a gas appliance for whatever reason, you probably want to cut off the gas supply RFN, and not after waiting for all the gas in the adjacent appliances to be burned off.

 

[Mat7783]

@ewo1 So I've asked about the vertical placement of the regulator, and I'm told that todays regulators that's not required. Too many installers needed regulators designed to work horizontally so designs have changed.

However, it is wise to install sediment traps in the event that your propane isn't clean coming out of the tanks. Most propane systems do not have sediment traps in-line, but systems can still benefit from it.View attachment 2389877

This is a picture of one I did in my house. it's simply a Tee with a down pipe into nothing. Any weighted impurities will fall down into the bottom and not go into your appliance. My regulator is also horizontal right behind that wall.

Also when using black pipe for gas I would highly recommend using the yellow pipe dope. The yellow thread wrap stuff doesn't work as well on black pipe I've found. I would wrap it quite well and still get leaks, and I had a retired Gas installer tell me always use the pipe dope with black pipe. Flared connections like the yellow line in the pic above is not supposed to use anything, Just ensure it's a tight snug fit.

When using the yellow pipe dope, it requires 24 hours to cure before pressurizing.

I'm not 100% sure on the regulations for RV setups though, but I thought I remember reading somewhere it's not recommended to use black pipe in mobile vehicles for some reason. I need to look into that. But many RV experts have warned against using it due to movement of the vehicle it can crack couplings.

I used a 5 outlet manifold off my 120 pound tank and shutoff valves on each line so I can isolate an issue without compromising complete system.

 

[Cannabus]

I'm getting real close to starting to implement our propane system. As such, I'm revisiting all the applicable/useful codes. ABYC (boats) is effectively a bit more stringent in some regards, so I'm considering them both together (as I have done with our electric system as well).

Both of these standards apparently require an interior shut-off valve PER APPLIANCE. My question is... why? I get it if the appliances are some distance away from each other, but say you have a range and a heater right next to each other (each well within the acceptable distance from shut-off valve to appliance listed in one or both standards). Wouldn't it make more sense to have a single point (one valve) where gas could potentially leak from, than multiples? Both standards are explicit in this 'one shutoff valve per appliance' mandate, so I figure I'm overlooking the logic in it. I just can't figure out why.

Aside from convenience (being able to shut-off one problematic appliance while keeping the others in play), is there another reason? Could it be because the volume of gas remaining in one appliance after shutting off the valve could feed back into the problematic appliance?

The way I see it, if you were to use 1 valve for an adjacent pair of appliances versus 2, the number of connections would be the same, but you'd consolidate those connections to just one point (which could be exactly where your propane leak sensor is mounted).

FWIW, I'm going to follow code to the letter. But... I really would like to understand the reasoning here. My tentative plan is to co-locate each of these two shut-off valves at a point in-between the two.

EDIT: The more I think about it, the more I'm guessing that the part I just bolded above is why. If you need to shut down a gas appliance for whatever reason, you probably want to cut off the gas supply RFN, and not after waiting for all the gas in the adjacent appliances to be burned off.

I used copper tubing as it’s recommended for use in RV’s. If installed properly it’s fine. Learn on how to correctly torque and make fittings. Fasten it to the wall with anchored zip ties. Use a gland going through the bus pan and use a cut off valve for each appliance so you can remove a failed or damaged unit and still continue to your stove or heaters. I covered all the tubes with protective wire wrap to prevent the possibility of items rubbing against them while driving.