Gas Line to New Shop

[Stig]

This is probably a question for my local inpsector, but I'm sitting here so I though I'd just throw it out there.

I'm building a 1,200sqft shop behind my house and I intend to install central heating and air. Because of the location of the service feed, and nearby trees it will be alot easier to extend the gas line from inside house rather than trenching around the house and trees. I'd tap into the furnace supply, then bring it to the opposite corner of the house before taking it underground to the shop.

Any thoughts on the use of polyethylene pipe ? Can I run that from the furnace to the shop, or should I stick with black pipe in the house, then tie into the polyethylene at the out wall for the rest of the run ?

[Rich]

If you bury it - I would say you'll want to run black pipe or poly inside a sleeve. Don't direct buy the poly pipe. I don't know if there is a problem with direct burial of poly - I would just want to be sure. A sleeve would be especially useful if you ever need to replace it :)

[roger g]

There are lots of variables. How far away is your shop and how many BTU's will it use? How many BTU's TOTAL for everything you use) What pressure are you running? How big are your existing gas pipes? Etc, Etc,
I've never heard of running iron (black) pipe under ground protected or not. I believe we used Type K copper tubing ( very thick) and buried it a prescribed distance plus in sand. Where it goes into the ground AND comes out of the ground the tubing must be protected ALSO there must be a shut off valve BEFORE going into the ground and just after it comes out of the ground. You can also use the plastic gas pipe but those val;ves must be used on them also.
Check with you local gas code in case it is different than mine.


roger

[Rich]

Just did an underground installation in black pipe inside a sleeve.. was signed off by gas company and building department.

[roger g]

Dang it Rich, you made me root around for an old code book. Most of my stuff is 3 hours away so I usuually go on memory. Sure enough, you're right, we can use pipe though I've never seen it used.
Oops, now that's a lie. I just remembered we were working on this job and when we went to fire up the unit it wouldn't fire due to the fact there was no gas coming though. This was early spring. There was ano old underground gas line about 200 feet long. We were advised by the gas company that probably what was happening was that condensation had formed an ice plug in the underground pipe due to the fact it hadn't been used for quite sometime. They advised us to put some antifreeze down the pipe and then pressure it up with air and wait which we did.
As I said before, this was early spring with lots of slush and puddles. After about 15 minutes I happened to notice air bubbles coming up through a puddle. A little later on I could see bubbles coming up almost the full 200 feet. Needless to say, the owner had a bigger problem then a blockage. I wonder why a person wouldn't use continuous copper or plastic. Always learn something on this site.
If you run gas pipe in something, it is called a chase, and in our code you must have a gap so if gas does escape from the pipe it must also clear the chase. Example: old code # 5.7.5 Each vertical piping chase shall have an opening at the top and bottom and the opening shall have a minimum area equivalent to a round opening of 1 inch in diameter.
roger

[Rich]

We ended up putting in what amounted to a clean out in the sleeve. The sleeve came out of the ground on both ends about 1 foot and then necked down to go pretty much tight to the pipe the clean out was about 4" from the top.

[RRG]

I work for a gas utility in Ohio. Diferent areas do things diferently, but here, black iron is used indoors and on new installation, yellow, or (older) orange 3/4" or 1" cts plastic is used in the yard.
Check with your inspector.

[Rich]

The utility company used 2" orange plastic into our 2 meters.

[roger g]

I think ours is about one inch. I don't think it's any bigger than that. I would think it depends on the pressure of the main lines. The main lines alongside our roads wouldn't be much bigger than 2 inch. Maybe 3 inches.


roger

[Rich]

We're pulling 2lbs of pressure to both meters - with 14" of w.c. - final w.c. will be 7".

[RRG]

Most pressures are considered high which is usually poundage, or low which is ounces.
High pressure lines can be smaller and require pressure regulators before the meter.
Ounces require a larger line.

[roger g]

I believe up here we have about 80 pounds BEFORE the metre which drops it to 7 inches of water column (1/4 pound). Here in BC it drops it to 2 pounds unless you request a low pressure metre, which I usually do. Back east we didn't have a choice in residential work. low pressure (7"wc) or nothing.
Of course when the gas actually goes through the final gas valve and into the burner, the pressure drops again to 3.5 wc.
Propane, in house pressures are higher than natural gas, about 14"wc but the pressure at the burner is still I believe 3.5"wc.


roger

[Rich]

Our black pipe runs in the house are 1-1/4" mains - haven't got all the info for the gas light fixtures and fireplaces yet.

[JCA]

I would reccomend the use of p[astic pipe underground, sleeved or not is your choice unless codes dictate otherwise. Whether you can run it from the furnace or not is a demand /supply question. If your system is low pressure then I would say no definately not. If system is medium pressure(2PSI) then it's possible. The best thing would be to have a plumber/Gas Piper to come and look.