Propane piping

Bus'n it · 07-08-2021, 08:49 PM

I will be installing the yellow jacketed copper line under the bus for my two appliances. One will be a 60,000 BTU Furrion tankless water heater and the other for a mini range/oven with unknown BTU's as I do not have it yet. So on my regulator, there is an output for 3/8". Should I run 1/2" line to the two appliances and step it down at the regulator, or go with 3/8" line altogether for those two appliances?

Danjo · 07-08-2021, 11:21 PM

Please read NFPA 1192. You can read it for free online.

I’d go with 1/2” black pipe to within 6 inches of the appliance connection and transition to flared 3/8” seamless copper tubing.

Doing black pipe is really easy. The only challenging part is determining your pipe length, but with a few fittings and an extra set of hands it’s not hard to figure out. Assemble with Teflon pipe sealant for use with propane, cap the ends and give it a pressure test. A flaring tool and a bender for the copper pipe and you’re all set.

Bus'n it · 07-08-2021, 11:43 PM

So after figuring out and signing onto the site, it looks like 3/8" will suffice for the BTU load I have. So even if I were to upsize it to 1/2" the regulator output port is 3/8" NPT. Should I just stay with 3/8" line or get an adapter to go from 3/8 to 1/2" Maximum length to farthest appliance is the water heater at 25' after taking all route paths. I have A/C tools which include a copper radius bender and flaring set.

Danjo · 07-08-2021, 11:53 PM

1/2” parts of all configurations are so much easier to find. Getting 1/2” threaded is so much easier to find .I haven’t seen any hardware stores threading 3/8 or stocking full sticks of it

Bus'n it · 07-09-2021, 08:45 AM

There's this internet store that has everything and makes it easy for people who have no patience for time spent searching at physical stores... It is called Amazon! They have both sizes of fittings in stock when I checked last night. They also have 3/8 and 1/2" Propane rated copper line that has a yellow PVC jacket. I order personal and business crap online. If my door step doesnt have a box in front of it on any given day, then something is wrong in my household! I buy 70% of electrical material online since my suppliers are either price gouging or simply have no stock.

o1marc · 07-09-2021, 11:40 AM

I ran 3/8" copper coil sheathed in rubber hose along the frame rail to the front of the bus for the tankless heaters and stove.

Oscar1 · 07-09-2021, 01:07 PM

Quote:

Originally Posted by o1marc

I ran 3/8" copper coil sheathed in rubber hose along the frame rail to the front of the bus for the tankless heaters and stove.

Directly from RIVA and the NFPA
Gas distribution.
5.3.2.5
(A) gas piping shall be steel or wrought iron pipe complying with ASTM 53, Specifications for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated Welded and Seamless.

(B) Threaded cooper or brass pipe in iron pipe sizes shall be permitted to be used.

Everything outside of the vehicle is solid with the exception of the breakaway on the regulator. Flexible cooper inside with as few fittings as possible, no sealants used inside, dry flaired fittings only.
The NFPA is a real long read but I think everyone doing some gas should get familiar with it.
Cheers

Bus'n it · 07-09-2021, 01:45 PM

This is where I get confuciated or confogliated… seems that new RVs and trailers are using copper with flare fittings. Aside from that why do they have the regulator output threads at 3/8?

Rucker · 07-09-2021, 03:02 PM

Quote:

Originally Posted by Danjo

1/2” parts of all configurations are so much easier to find. Getting 1/2” threaded is so much easier to find .I haven’t seen any hardware stores threading 3/8 or stocking full sticks of it

I second this. LPG is very low pressure so large appliances may see a pressure drop over longer distances.

Also, half inch pipe is readily available for the seventeen trips to the hardware store to get the fittings right.

Danjo · 07-09-2021, 03:29 PM

Quote:

Originally Posted by Rucker

the seventeen trips to the hardware store to get the fittings right.

No! Just buy everything and take back what you don’t use. You’re still going to get it wrong and need to go 3 times.

Danjo · 07-09-2021, 03:42 PM

Quote:

Originally Posted by Bus'n it

There's this internet store that has everything and makes it easy for people who have no patience for time spent searching at physical stores... It is called Amazon! They have both sizes of fittings in stock when I checked last night. They also have 3/8 and 1/2" Propane rated copper line that has a yellow PVC jacket. I order personal and business crap online. If my door step doesnt have a box in front of it on any given day, then something is wrong in my household! I buy 70% of electrical material online since my suppliers are either price gouging or simply have no stock.

Suit yourself. What a PITA to get what you need that way when you can’t foresee exactly what you need. And the pennies you save help drive the nail in the coffin of your local stores just a little deeper.

Rucker · 07-09-2021, 03:47 PM

Quote:

Originally Posted by Danjo

No! Just buy everything and take back what you don’t use. You’re still going to get it wrong and need to go 3 times.

You actually return parts???? I have a dinky bag of PVC fittings I've been meaning to return since last summer.

Everything else I buy for the bus ends up in spare parts, at least so far. When I'm done with this shuttle I'll be stocked to do another two or three of them, I think.

Danjo · 07-09-2021, 03:52 PM

Quote:

Originally Posted by Rucker

You actually return parts???? I have a dinky bag of PVC fittings I've been meaning to return since last summer.

Everything else I buy for the bus ends up in spare parts, at least so far. When I'm done with this shuttle I'll be stocked to do another two or three of them, I think.

It depends on what it is. When I’m doing plumbing I purposely overbuy and I’m careful to keep everything in good condition so it can be reshelved. It doesn’t always work out. I have 30 gallons of electrical I’ve been hauling around for a decade

Bus'n it · 07-09-2021, 04:26 PM

Quote:

Originally Posted by Danjo

Suit yourself. What a PITA to get what you need that way when you can’t foresee exactly what you need. And the pennies you save help drive the nail in the coffin of your local stores just a little deeper.

Actually I can foresee what I need and the local stores do not carry much if any flare fittings. I’ve been let down spending time perusing stores where they cater only to the DIY homeowner rather than the contractor. The nail has been driven way before me. Please don’t look at me as the enemy on that. It works for me. We spend 4-8k monthly locally due to the nature of my business. That said with shortages happening, I can only source materials online to keep my guys working.

Really looking to see if there is any reason not to run 3/8 vs 1/2 for the two appliances. Either lineset has to be special ordered as HD or Lowe’s do not carry it.

I too buy more than I need when I do go to the above stores and hardly ever return.

Rucker · 07-09-2021, 04:33 PM

I'm loving this conversation, by the way.

Bus'n it · 07-09-2021, 04:37 PM

Me too but I’m still confused which way to go! I have spent hours searching online for info. Most that I see did it wrong with rubber hoses everywhere or debate on copper Vs black pipe. None show what they finished with. Liability I guess?

Danjo · 07-09-2021, 05:01 PM

Quote:

Originally Posted by Bus'n it

Me too but I’m still confused which way to go! I have spent hours searching online for info. Most that I see did it wrong with rubber hoses everywhere or debate on copper Vs black pipe. None show what they finished with. Liability I guess?

I did iron pipe. The thing about iron pipe is that it is nearly indestructible. And the copper flare fittings I have made have also held up nice. So you could have a road hazard hit that iron pipe at 70 MPH and it wouldn’t do a thing. Likewise, you won’t have to worry about abrasion from sheet metal.

The thing about rubber hoses is that they don’t hold up to abrasion and the swaged ends can fail catastrophically, instantly filling the cabin with propane. NFPA 1192 allows the connection to the propane tank to be rubber and I did that.

With the exception of appliance whips, I don’t have experience with the flexible copper tubing, but that stuff is pretty thin-walled and won’t be as resistant to abrasion or puncture as iron pipe.

Only thing about iron pipe is that it rusts so you’ll want to paint it. I think galvanized is allowed now. There was a time that the zinc would flake off the inside of the pipe and clog stuff up, but I read somewhere that they fixed the plating process and it’s no longer the case.

Rucker · 07-09-2021, 05:09 PM

Quote:

Originally Posted by Bus'n it

Me too but I’m still confused which way to go! I have spent hours searching online for info. Most that I see did it wrong with rubber hoses everywhere or debate on copper Vs black pipe. None show what they finished with. Liability I guess?

I recommend use black iron wherever you have a run through walls or over a couple of feet. Flex copper is soft, and although safe when installed properly, it is still a failure point if subjected to vibration over time. Flex Corrugated Stainless Steel is similar. Black iron is far, far superior to copper. And whichever you use, make sure you ground every section of pipe.

I've mentioned elsewhere that I was going to run black iron to both the water heater and the camp stove in the kitchen. After researching, I decided not to create an extensive distribution system. (I'm not full time, just long weekend boondocking).

I have flex rubber supply from the barbecue tank in a sealed enclosure to 1/2" black iron that just makes a few right angles over six feet, then converts back to flex rubber hose to the inlet of the water heater. The hoses are on a 24 month preventive maintenance schedule (replace every two years).

The camp stove is powered by single use propane tanks. The black iron has a tee, capped, just in case I get tired of single use tanks one day, or want to buy a bigger stove.

Danjo · 07-09-2021, 05:16 PM

1/2 NPT to 3/8 flare are easy to find. You can buy an inexpensive flaring tool or borrow one. The husky one with the torque-limiting screw is nice.

To make the flared connections you’ll need 3/8” seamless copper tubing, a copper pipe cutter, flaring tool and an inexpensive tubing bender.

The way I do it is to take a price of tubing longer than you need, flare the end that will connect to the flare on the pipe side. Put a short flare nut on and screw it to the flare fitting on the pipe. Figure out where your bend will start and how many degrees you need. Mark the tubing with a sharpie where the bend will start. Remove the tubing from the flare fitting. Make the bend. Reinstall. If you need another bend, do the same. When you get to the flare in the appliance side, mark for the cut. Add 1/4” for the flare. Cut the tube. Place a short flare but on the tube. Flare the end.

Oscar1 · 07-09-2021, 05:19 PM

Hey Simon
I think Danjo has the answer, keep the pipe big until you get to the appliance then downsize where needed. Some draw big volumes of gas so the bigger pipe will provide the volume, when running pex in a house for water why do we run 3/4” or even 1” for the mains and then step it down at the fixture? For the volume. Sorry I don’t have the answers, I’m still digging thru tons of gas info myself. It doesn’t make sense to come off the regulator at 3/8” then step up to 1/2” but maybe that volume in the main is the ticket.
Good luck

Oscar

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