Propane tubing in wall? RV code confusion

[TheHubbardBus]

So, I'm trying to edumacate myself of propane.

Reading through NFPA 1192 right now (fire code for RVs), and the following has me confused:

"tubing or hose shall not be run inside walls, floors, partitions, or ceilings".

For anything floor-level, this is not a problem... I can tee-off underneath the bus directly below the appliance and route my copper tubing directly to it through a proper floor penetration.

However, we'll be feeding one appliance - a direct-vent propane furnace - which will be mounted ~3-4 feet up, ON A WALL.

How do I run tubing to it, in a safe & code-complaint manner, without running the tubing inside the wall?

[o1marc]

Oops. I ran a PEX gas line under my finished floor from one side to the other. I could get it out in a pinch, but couldn't get it back in after. I don't have any connections that are not accessable.
If you have to run it out side the wall, use fasteners to secure copper piping to the wall.

[Drew Bru]

You could build a pipe chase, unless that's considered a wall? If nothing else, can you run black steel gas pipe and leave it exposed? It's rustic, if that's your thing.

[TheHubbardBus]

Originally Posted by o1marc

If you have to run it out side the wall, used fasteners to secure copper pipe[ing to the wall.

Yeah, it's looking like that might be the only option? Maybe I'm missing something. Not what I was hoping for aesthetically speaking, but it is what it is.

[TheHubbardBus]

Originally Posted by Drew Bru

You could build a pipe chase, unless that's considered a wall? If nothing else, can you run black steel gas pipe and leave it exposed? It's rustic, if that's your thing.

I guess something like that is going to have to become my thing. I'll just pass on the task of making it look pretty to the wife.Think rigid copper could look pretty descent.

[Drew Bru]

Originally Posted by TheHubbardBus

Think rigid copper could look pretty descent.

Yeah, that could work as rustic or you can lacquer it and keep it shiny. Could probably even give it a green patina. Paint it too if you want.

[o1marc]

Originally Posted by TheHubbardBus

I guess something like that is going to have to become my thing. I'll just pass on the task of making it look pretty to the wife.Think rigid copper could look pretty descent.

And you can polish it for aesthetic value. Fortunately I can powder coat the metal bits to match what ever.

[TheHubbardBus]

Hmmm... all good ideas. Thanks guys! I've gone from confused to disappointed to thinking this might just end up working & looking great, all in the the course of 15 minutes

[banman]

Hubbard,
"tubing or hose shall not be run inside walls, floors, partitions, or ceilings".

I think black pipe is your answer -- run inside the wall.

Can't speak to the letter of the code, but the purpose of the code is safety -- it's too easy to pierce copper tubing with a nail or screw hanging up a picture etc.

Black pipe will turn a nail.

If you're actually be inspected to this level, than the inspector/inspecting agency should be able to confirm my interpretation of the code.

Or ask an RV builder what they do...

Or move your furnace down towards the floor...

[TheHubbardBus]

I appreciate the advice, Banman.

My concern (potentially unfounded - again I'm learning) w/ black pipe inside the wall is that I'd have to exit it out the wall, which would mean 2 joints (A 90 & a nipple) would be concealed w/in. That is also not to code, I'm assuming because a gas leak from such joints could easily go undetected while filling the cavity.

[family wagon]

The concern for a joint developing a leak in a concealed place is a valid one.


I think a decorative cover, cabinet, etc to cover the pipe is a fine idea. It would be well ventilated to the room such that if there's a gas leak you'll be able to smell it right away. It'll also be easily removed for inspection.

[Iceni John]

I'm using 1/2" Pro-Flex CSST (the flexible stainless steel gas pipe) inside 3/4" EMT conduit for protection, and in exposed areas such as running near the front wheel to the generator I also put the EMT inside some seamless thickwall stainless pipe for extra protection. With some imagination it would be possible to come up with a safe and aesthetically-pleasing way to get propane where it's needed.

While NFPA 1192 has some good advice on tank and cylinder location, it's completely behind the times when it comes to newer developments such as CSST. CSST is designed to be put inside walls with the appropriate protection plates, and if you run it inside well-secured rigid metal conduit as well I really can't think of any reason it would cause problems in a vehicle. As is so often the case, the rules and regulations need to acknowledge the existence of newer technologies. Good ol' black iron rigid gas pipe is not the only game in town these days. Personally I prefer to keep the number of joints to an absolute minimum, and running uninterrupted lengths of CSST direct from the manifold to each appliance without intermediate joints or connections is intrinsically safer for a moving vehicle; so saying, if it needs a short flexible connector into the appliance itself then I'll add one.

John

[Danjo]

Black pipe

[Willie_McCoy]

Originally Posted by TheHubbardBus

Reading through NFPA 1192 right now (fire code for RVs), and the following has me confused:

"tubing or hose shall not be run inside walls, floors, partitions, or ceilings".

This is a correct interpretation of the code, per NFPA, no tubing (copper or CSST) can be run in a "concealed" (walls, floors, partitions, ect) location. Decorative coverings are acceptable but cant require special tools for removal or be vapor tight.

Originally Posted by banman

Hubbard,

I think black pipe is your answer -- run inside the wall.

Can't speak to the letter of the code, but the purpose of the code is safety -- it's too easy to pierce copper tubing with a nail or screw hanging up a picture etc.

Black pipe will turn a nail.

This is true, one reason for not allowing TUBING in concealed locations is its ability to be penetrated accidentally in addition to developing leaks at fittings from vibration, where PIPING is permitted to be run in concealed locations, due to its inherent strength, but its fittings are not.

"5.3.9.1 Pipe or tubing joints shall not be located in any floor,
wall, partition, or concealed construction space."

Originally Posted by Iceni John

I'm using 1/2" Pro-Flex CSST (the flexible stainless steel gas pipe) inside 3/4" EMT conduit for protection, and in exposed areas such as running near the front wheel to the generator I also put the EMT inside some seamless thickwall stainless pipe for extra protection. With some imagination it would be possible to come up with a safe and aesthetically-pleasing way to get propane where it's needed.

While NFPA 1192 has some good advice on tank and cylinder location, it's completely behind the times when it comes to newer developments such as CSST. CSST is designed to be put inside walls with the appropriate protection plates, and if you run it inside well-secured rigid metal conduit as well I really can't think of any reason it would cause problems in a vehicle. As is so often the case, the rules and regulations need to acknowledge the existence of newer technologies. Good ol' black iron rigid gas pipe is not the only game in town these days. Personally I prefer to keep the number of joints to an absolute minimum, and running uninterrupted lengths of CSST direct from the manifold to each appliance without intermediate joints or connections is intrinsically safer for a moving vehicle; so saying, if it needs a short flexible connector into the appliance itself then I'll add one.

John

John,

I have to respectfully disagree with this, CSST is addressed by the standard and it is considered to be a TUBING (CSST=Corrugated Stainless Steel TUBING),

"3.3.60* Tubing. Semirigid conduit of copper, steel, aluminum,
corrugated stainless steel tubing (CSST), or plastic. [54, 2015]"

and as such according to NFPA should not be run in a concealed location in a mobile application. While I like CSST for fuel gas piping, and I have personally run miles of it in all sizes from 1/2"-1.5", I understand their need to handle it differently in a mobile environment. While in residential construction CSST and its associated fittings are run concealed with appropriate protection from penetration, the mobile environment brings different hazards to the table, most concerning to the NFPA types is vibration. I believe their concern is that the corrugations will work harden over time from vibration and create a potential for a failure point. In addition the fittings used on CSST are a special type of compression/flare fitting with a brass ring to lock in the corrugation. Think these would be more susceptible to loosening from vibration than traditional threaded connections. That being said, I personally think it is extremely unlikely and I think the murderous overkilll inherent in your plan is more than sufficient to be safe under operation, and if I was inspecting it, as the AHJ, as long as there were no concealed fittings, I would probably give it the green light under the equivalency clause.

"1.5 Equivalency. The provisions of this standard shall not be
intended to prevent the use of any material, method of construction, or installation procedure not specifically prescribed by this
standard, provided any such alternate is acceptable to the authority having jurisdiction. The authority having jurisdiction shall require that sufficient evidence be submitted to substantiate any
claims made regarding the safety of such alternatives."

Source: 3rd generation Master Plumber & Pipefitter, & now Asst. Dep. State Fire Marshall as well.

[Willie_McCoy]

All that being said, I plan to run concealed CSST for our propane system with a manifold at the tanks, and no concealed fittings.

[Danjo]

Originally Posted by Iceni John

I'm using 1/2" Pro-Flex CSST (the flexible stainless steel gas pipe) inside 3/4" EMT conduit for protection, and in exposed areas such as running near the front wheel to the generator I also put the EMT inside some seamless thickwall stainless pipe for extra protection. With some imagination it would be possible to come up with a safe and aesthetically-pleasing way to get propane where it's needed.

While NFPA 1192 has some good advice on tank and cylinder location, it's completely behind the times when it comes to newer developments such as CSST. CSST is designed to be put inside walls with the appropriate protection plates, and if you run it inside well-secured rigid metal conduit as well I really can't think of any reason it would cause problems in a vehicle. As is so often the case, the rules and regulations need to acknowledge the existence of newer technologies. Good ol' black iron rigid gas pipe is not the only game in town these days. Personally I prefer to keep the number of joints to an absolute minimum, and running uninterrupted lengths of CSST direct from the manifold to each appliance without intermediate joints or connections is intrinsically safer for a moving vehicle; so saying, if it needs a short flexible connector into the appliance itself then I'll add one.

John

The only problem I see is protection. The exterior walls of buses are too narrow to guard against possible nail and screw damage. The outside skin is either steel or aluminum which could be considered protection, but the nature of the material dictates drill bits and sheet metal screws and rivets, so protection should be robust, as in, no screw or nail can pierce and when you’re drilling you wonder why it’s so damn hard.

If properly protected from puncture or abrasion CSST is a great material.

[TheHubbardBus]

Great discussion. Really appreciate everyone's input. It's good to have the distinction between tubing & pipe defined in the context of what can be ran where. I figured that was one significant distinction, but the code portions I had read didn't make it glaringly clear.

So while I have y'all on the line, so to speak, here's my tentative plan. Let me know if anyone sees a problem, or improvements:

1) properly-sized black pipe well-secured under the bus, as main distribution 'backbone', running to the approximate location of each appliance.

2) for each appliance: a gas shutoff valve off the black pipe, into K/L copper tubing, which then penetrates the floor and runs directly to appliance. Floor penetration protected by rubber grommet.

3) For my problem-child run, everything the same except copper pipe instead of tubing (purely for aesthetics), left exposed. (alternatively, copper tubing covered by something decorative, but removable, as suggested above).

Also, what would be the best thing to use from the tank regulator to the black pipe?

[Danjo]

Originally Posted by TheHubbardBus

I appreciate the advice, Banman.

My concern (potentially unfounded - again I'm learning) w/ black pipe inside the wall is that I'd have to exit it out the wall, which would mean 2 joints (A 90 & a nipple) would be concealed w/in. That is also not to code, I'm assuming because a gas leak from such joints could easily go undetected while filling the cavity.

I would run rigid black pipe from the outside at the tank to each appliance location. All the joints need to be sealed with an approved thread sealant. I would use Teflon pipe dope. After that’s installed, cap all the outlets with a black pipe cap and a test gauge. Pump the test gauge to 16 pounds and let it sit for an hour. If it reads 16 pounds after an hour, it is leak-free and ready for installing the appliances. Each connection needs a gas valve installed at the appliance. The appliance connections are seamless copper tubing that’s been flared. I think the NFPA specifies a 45 degree flare. You’ll need to check that. It’s a deviation from residential, I think, to withstand vibration.

[Danjo]

Originally Posted by TheHubbardBus

Great discussion. Really appreciate everyone's input. It's good to have the distinction between tubing & pipe defined in the context of what can be ran where. I figured that was one significant distinction, but the code portions I had read didn't make it glaringly clear.

So while I have y'all on the line, so to speak, here's my tentative plan. Let me know if anyone sees a problem, or improvements:

1) properly-sized black pipe well-secured under the bus, as main distribution 'backbone', running to the approximate location of each appliance.

2) for each appliance: a gas shutoff valve off the black pipe, into K/L copper tubing, which then penetrates the floor and runs directly to appliance. Floor penetration protected by rubber grommet.

3) For my problem-child run, everything the same except copper pipe instead of tubing (purely for aesthetics), left exposed. (alternatively, copper tubing covered by something decorative, but removable, as suggested above).

Also, what would be the best thing to use from the tank regulator to the black pipe?

For point #2, run black pipe to the appliance and install the shut off there. Then the flared. copper tube the last foot.

[Danjo]

no concealed fittings allowed. I need to remind myself that a bus is not a house.