PEX for propane- makes, fittings?

[pybyr]

Hi- longtime Hearth.com person, but new to the "gas" side of things.

I need to replace my old oil-fired standalone water heater before it catastrophically fails, which it is at risk of doing at any point from sheer age, and am seriously considering a propane unit- already have propane on site for the kitchen cookstove.

I've plumbed gas years ago with flared copper, and a bit with black iron, and have plumbed all sorts of stuff with all sorts of materials for plumbing and heating.

I was a late and skeptical convert to PEX for water but have come to love the stuff. My main experience has been with Wirsbo and I own their tool (thankfully purchased at a fraction of new cost from a retiring plumber).

I am seriously considering PEX for new propane lines in connection with the W.H. project.

Can folks please fill me in on their experience with different types and makes of yellow PEX, and options for fittings, for propane/ natural gas?

Thanks!

 

[coaly]

Plastic LP lines are a common supply line underground for longer runs, buried in sand. The type I've used require a electric heater to melt connections together. They also use a riser to come out of the ground with threaded fitting for connection. When I used Ray Murry as a propane equipment supplier, I had to take a course at their main warehouse to be able to purchase the tubing and fittings. Not aware of Pex making a product for that application. I believe it's polyethelene, not cross linked poly like Pex.
Not much has changed with propane plumbing materials.
For propane, you can use Type L copper with plastic sheath to protect from contact with lime in cement. Type L can also be direct buried or penetrate through walls, ceilings and floors. No refridgeration tubing can be buried, but it can be used for LP supply where accessible only. Black iron schedule 40 is required within walls.

 

[jrems]

I used 316 grade stainless tubing. It was actually cheaper than copper. Flared it just like copper. I'm sure it could be buried or put through concrete. Plus it's shiny!

 

[coaly]

Below is why that would not be an approved piping material listed under NFPA 58 Standard.
Only Corrugated Stainless Steel Tubing (CSST) is an approved stainless material when used with manufacturers supplied fittings. Many local codes require installer certification.

Flared joint criteria from NFPA 58 reads;
"Flared joints shall be used only in systems constructed
from nonferrous pipe and tubing where experience or tests have
demonstrated that the joint is suitable for the conditions and where
provisions are made in the design to prevent separation of the joints".

It has to do with the ductility of soft copper not cracking like harder materials when forces are applied to it.

 

[Heatsource]

(broken link removed to http://www.tracpipe.com/CSST_Gas_Pipe_Products/CounterStrike_CSST/)
i've used this stuff, it is a great product, but fittings are a bit expensive

only tool you need is a tubing cutter that will do stainless. a sharp tubing cutter helps make a clean cut

 

[jrems]

This was annealed( ductile) Stainless. It is soft and made to be bent and flared. It's often used in brake lines in cars and is flared and does not leak on cars, even with thousands of psi. It's also non ferritic- ( austenitic) stainless.

 

[eclecticcottage]

Hm...just posting so I remember to keep an eye on this thread. We wanted to move our two 100lb LP tanks to a spot a little ways from the house so they weren't so visible. That would mean burying pipe, so this is interesting to see different options for pipe.

 

[heaterman]

I'd have to check my code books but as far as I know.....

Plastic is approved only for direct burial outdoors and may not be used inside a house. If you run it to the house from a tank you must transition to steel before going through the wall and the pentration must be above grade.

All penetrations through walls and floors must be done in steel if using CSST.

 

[pybyr]

I'd have to check my code books but as far as I know.....

Plastic is approved only for direct burial outdoors and may not be used inside a house. If you run it to the house from a tank you must transition to steel before going through the wall and the pentration must be above grade.

All penetrations through walls and floors must be done in steel if using CSST.

Thanks Heaterman. I thought I'd run across some PEX-AL-PEX somewhere that was specifically for propane/natural gas (it was yellow) but now I cannot recall what make or what vendor/ website I'd seen it at. With the lack of uniformly shaped construction materials in my old house cellar, something like this would be way easier to work with than black iron. Greatly appreciate any information that you come up with.

 

[heaterman]

Thanks Heaterman. I thought I'd run across some PEX-AL-PEX somewhere that was specifically for propane/natural gas (it was yellow) but now I cannot recall what make or what vendor/ website I'd seen it at. With the lack of uniformly shaped construction materials in my old house cellar, something like this would be way easier to work with than black iron. Greatly appreciate any information that you come up with.

Good old flared soft copper can also be used once inside your house.
Watch the carry capacity though. 30 Feet of 5/8" tube will only supply about 110,000 btu worth of fuel at a .5" pressure drop.
Sometime we'll use a short run of soft copper and then connect to steel at a point where access is better or offers a straight shot to the appliance.

Plastic is most definitely not approved for interior use. At least that's the answer I got from the code people here.

 

[altmartion]

I did see pex used on a vent free heater in a bar once. I about fell over. he said it had been like that for quite a few years and never leaked. crazy bastard. he was a plumber too!! they do make fittings to be used with inert gasses but I have never seen for lp or ng. your or a lp provider may sell you some of the tubing they use. personally I use coated copper for lp if it is outside, then I switch to csst.