Author Topic: Running Natural Gas in PEX for a stove?  (Read 30119 times)

S0VERE1GN

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Running Natural Gas in PEX for a stove?
« on: May 01, 2014, 06:27:47 AM »
Hey all,

so, I'm completely new to plumbing, and Ive read up about it (time invested, 7 minutes) a little so I understand the general ideas behind plumbing and so forth.

Now, I have two jobs in my house I want to tackle soon

1) run electrical and piping for the dishwasher
2) run natural gas piping for our new stove.


I haven't been able to find a whole lot about running natural gas lines in your home, safety concerns, checking for leaks etc. and so I was hoping you all could give me a resource, or just some general tips before I go blowing my house apart.

Thanks!

Greg

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Re: Running Natural Gas in PEX for a stove?
« Reply #1 on: May 01, 2014, 08:16:38 AM »
Gas is usually run in cast iron black pipe.  Using pipe dope at the joints, you assemble the line with the joints that screw together as needed.  Use pipe wrenches to get them very tight.  You test by pressurizing the line with something with a shraeder valve and gauge on it.  It has to hold a certain pressure for a certain time, like 15 psi for an hour.  You can also check for leaks at every joint using soapy water to look for bubbles.  Overall this is the DIY way.

This is a pressure tester I would recommend, sometimes available at your local hardware store:
http://www.ronshomeandhardware.com/13-1891-0-To-15-PSI-Gas-Test-Gauge-p/665347.htm

Pros would probably use sheathed stainless flex line.  It's like the small flex lines that connect to appliances, but comes in rolls and is usually 3/4" thick.  It has a yellow pvc sheathing on it to protect it and identify it as a gas line.  The joints are a kind of compression fitting that uses rubber seals.  The end points are brass and stainless fittings.  If you know a plumber who will get it for you, this is the better way to go.

Either way you won't blow you house up unless there's a leak or you forget to turn the gas off at the meter or regulator where it comes into your home first.  That's why you test with the gauge and soapy water.  Gas is heavier than air so it settles near the floor, in crawlspaces and garages.  You want to think about where combustion sources like standing pilot lights are when working.  This is also why furnaces in garages are on pedestals.

Natural gas and propane both have odorants added to help you detect leaks, but your sense of smell is easily trained to ignore the odors so it's not for testing for leaks.

S0VERE1GN

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Re: Running Natural Gas in PEX for a stove?
« Reply #2 on: May 01, 2014, 09:57:44 AM »
Thanks so much for that overview. I am still officially afraid of attempting this. will try and find more information. lol

Greg

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Re: Running Natural Gas in PEX for a stove?
« Reply #3 on: May 01, 2014, 11:12:34 AM »
As to your original post title, PEX is only used for gas lines underground as far as I know.

GuitarStv

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Re: Running Natural Gas in PEX for a stove?
« Reply #4 on: May 01, 2014, 01:04:27 PM »
Natural gas and propane both have odorants added to help you detect leaks, but your sense of smell is easily trained to ignore the odors so it's not for testing for leaks.

I always thought that there were things added to natural gas to make it smell and help detect leaks too but when we had a gas leak after getting a new furnace installed it didn't smell strongly at all . . . just faintly like some kind of fuel.  It wasn't until I dribbled some water over the pipe joints and saw bubbling that I figured out what the problem was.

Exflyboy

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Re: Running Natural Gas in PEX for a stove?
« Reply #5 on: May 01, 2014, 01:26:57 PM »
Just a small correction Greg, The threaded gas pipe is actually steel.. not cast iron. Cast iron would be notch sensitive (i,e not malleable) which is definately not what you want in a gas pipe...:)

Natural gas is also lighter than air.

In is natural state, natural gas is odourless so a small amount of very smelly gas (mercaptan) is added to give it its distinctive smell.

I personally am not aware of PEX being used for NG (it maybe but I have never come across it).

Pex is definately decayed by UV so if it is approved it would almost certainly be for below ground use.

Greg

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Re: Running Natural Gas in PEX for a stove?
« Reply #6 on: May 01, 2014, 01:42:15 PM »
Just a small correction Greg, The threaded gas pipe is actually steel.. not cast iron. Cast iron would be notch sensitive (i,e not malleable) which is definately not what you want in a gas pipe...:)

Doh!  Typing too fast, you're right.

Natural gas is also lighter than air.

Double doh!  I was thinking only of propane when I wrote that.  Thanks fro the corrections.

In is natural state, natural gas is odourless so a small amount of very smelly gas (mercaptan) is added to give it its distinctive smell.
I personally am not aware of PEX being used for NG (it maybe but I have never come across it).

Yes, natural gas smells like rotten eggs or garlic, which is the added scent.  Around here, Pex is used for underground gas piping of both natural gas and propane.  It's yellow polyethylene similar to plumbing pex but not as thick walled usually.  Where it come up out of the ground, a metal elbow is used to make the turn and be the stronger exposed part.  It shoves onto the pex just like a sharkbite fitting, and usually has a male threaded end for making the transition to a regulator, shutoff and on to the house piping.

Roland of Gilead

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Re: Running Natural Gas in PEX for a stove?
« Reply #7 on: May 01, 2014, 04:05:02 PM »
The yellow flexible stuff is what they used for a 20 foot run in our home.  This was for propane though.  I think it is the sheathed stainless flex line Greg was referring to.

I did just finish up all of the propane runs for our custom camper build.  I used 3/8" copper tube with flared fitting though and I doubt that is code for houses.  I had a 0 to 15 psi gauge already and hooked it up to one of the fittings and measured the 0.4psi from the two stage regulator.  I let it sit for 3 days and it still read 0.4psi (with the main gas cut off) so no leaks!

S0VERE1GN

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Re: Running Natural Gas in PEX for a stove?
« Reply #8 on: May 02, 2014, 06:49:09 AM »
Hm. All very interesting. I have a plumber at the ready who is a family friend to install these gas lines for me....I think I might see if he's okay with me hanging around with him while he does it so I can learn for the future (as a van camper build is in my future ^_^)