View Full Version : Running a natural gas line???

Doug Jones
09-12-2003, 2:29 PM
I just got a vent free gas heater for the shop/ garage, for winter heating. I was wondering if running a line is difficult or not. Or is this something I should have a professional do?. I am aware of the hazards if fittings are not connected corectly and all the warnings and how to check for leaks. But I have never done this before and I need some opionins/help on this. (Don't want to blow up the whole house and all)

Should I tie into the line that runs to the upstairs room and run it across the attic then down into the garage or tie into the line under the house drill a hole in the block then into the garage? Can I run the new line outside along the foundation (aprox. 7 ft.)then into the garage?

Is copper pipe ok or should I go with the heavier galvanised pipe?

Any help is greatly appreciated, Doug

Steve Clardy
09-12-2003, 2:50 PM
Doug, I would hook to the line under the house then to garage. I would think having all that extra line in the attic might be a future problem. I would keep it outside as much as possible.
On the line, I do not see a problem with copper. I use L.P. gas, and have two coppers underground.
But there are no codes here on this, so check your codes first. They may require something else. Better to do it their way first than having to do it twice. Steve, not a pro gas hooker-upper. Steve

Jim McFall
09-12-2003, 3:38 PM
I have run miles of Natural gas piping for furnaces in houses. Tap in where it is the closest. If you go' thru a block wall, put a plastic sleeve over the pipe and then just put some caulk around the hole.
I highly recommend Black Iron pipe. Do not use Copper. It is effected by the chemicals in the gas and then it flakes off and clogs the gas valve on your unit.

Most likely your furnace had been piped in black iron pipe. take a look at how that was done and copy it. I also suggest you put in what is called' a "drip leg". that is a "T" that you use instead of an elbow to make the last turn into the unit. the lower opening of the "T" is then closed up using a short nipple and a cap. anything (moisture or debrie) traveling with the gas should then drop into this nipple and not make it's way' intop the units gas valve. Use pipe dope and tighten firmly but you do not have to really crank on the wrench. a 12 to 14 inch wrench will be all that is necessary for 1/2 inch pipe. If you are going more that 20 feet, you should start with 3/4 pipe till you get within 8-10 feet and then you cah switch to 1/2 inch. I will explain better if you have any questions. Jim

Kevin Gerstenecker
09-12-2003, 4:18 PM
I would do exactly as Jim described. Black Iron is the way to go........it is available at the big Box stores, and most hardware stores. Easy to do, and you can check for leaks with some soapy water. Dishwashing liquid works fine........if there is a leak, you will see bubbles. Pretty easy project, and those ventless Gas Heaters work great. Should keep you toasty! :D (Also, don't confuse the Galvanized Iron Pipe with Black Iron............you want to use Black Iron.)

Brad Schafer
09-12-2003, 11:48 PM
Doug -

No need to run outdoors if you already have a line in the house. Hopefully you already have a T in the existing line (which should be black pipe); otherwise, you'll have a little patching to do.

I've attached a couple of pictures of a drip leg if it helps.

Affirmative on pipe dope and brushed soapy water.

Oh yeah - don't forget to turn the gas off first. DAMHIKT (always wanted to use that). :D


Doug Jones
09-13-2003, 9:28 AM
WoW, thanks for all the info everyone. I am almost to the point where I believe I can do this with out blowing up half of C-ville.

Do you use the same kind of pipe dope as you would on pvc pipe ? Or is this special for black iron?

So to recap then, Black iron pipe, pipe dope, teflon tape, wrench, and drip leg. So far so good.

Thanks again

Jason Roehl
09-13-2003, 10:01 AM
WoW, thanks for all the info everyone. I am almost to the point where I believe I can do this with out blowing up half of C-ville.

Do you use the same kind of pipe dope as you would on pvc pipe ? Or is this special for black iron?

So to recap then, Black iron pipe, pipe dope, teflon tape, wrench, and drip leg. So far so good.

Thanks again

The pipe dope that Brad is referring to is in lieu of the Teflon tape, Doug, and it is NOT the same thing as what you glue together PVC with. And, I do believe that there are several different types (hardening and non-hardening), some of which are not adequate for gas. Check labels and ask the plumbing dept. dude whereever you get the black pipe. Alot of places will cut it and thread it for you free. There are also short "nipples" that come pre-threaded--you'll need several of those to make the drip leg. Have fun!!

Kevin Gerstenecker
09-13-2003, 12:24 PM
Doug, there is a Thread type Tape application that is approved for Natural Gas..........it is thicker than the White Teflon Tape you often see used for Plumbing applications. The Gas Approved Thread Tape is Yellow in color, but I think I would stick with Paste Type Pipe Dope........I just don't trust the thread tape on Gas Lines. The Local Gas Company, Illinois Power, doesn't use the tape, so they must know something we don't? Oh, and by the way..............You shouldn't cut the Black Iron Pipe with the New Miter Saw.............no matter how badly you want to! (I couldn't resist that one!) :D

Bruce Page
09-13-2003, 1:38 PM
Doug, thereís some good advise here, (definitely go with the black pipe). Before I installed my shop heater, I grilled my neighbor who owns a heating/air conditioning shop.
The three points that he stressed were:

1. Before you start, make sure that you have enough pressure in the line to handle the additional appliance. You donít want to starve your home furnace, water heater etc., if everything is running at the same time. In my case, he came over with a pressure gage and checked my line pressure and it was ok.

2. Keep the number of joints to a minimum. Donít just buy off the shelf pipe and try to kluge it together with nipples & couplings I measured the different lengths that I needed and had the pipes cut & threaded to fit.

3. Use brass fittings whenever the line material changes, e.g. black pipe to stainless.

All in all, it wasnít too difficult to install, I think it took me the better part of a weekend to complete. I ended up with a few extra lengths of pipe, but the installation looked professional. When I was finished, I had my neighbor come over and give it his unofficial blessing. Iíve been nice & toasty since.

Von Bickley
09-14-2003, 12:00 AM
Around here, the code use to be "black iron" and "NO Bushings". If you need to step down in size, you need to use a "bell reducer".

Lee Schierer
09-15-2003, 12:48 PM
Teflon tape is a thread lubricant, not a sealer, it aids in pipe assembly but is really not a sealant. It also tends to shred and the shreds will clog valves and regulators. You would be much farther ahead to use Loctite 511 Pipe sealant (no affiliation), just stay back one full thread from the end when you apply it. Most Industrial or Plumbing supply houses carry it.

Don't use copper. The acids in natural gas can cause it to develop pinholes in a short time Most codes don't allow copper. Galvanized pipe also has some problems with natural, but I don't recall what they were.

Don Farr
09-15-2003, 1:10 PM
I want to install an overhead heater like Bruce posted pictures of, but my shop is 75 feet from the propane tank. I learned a bunch that I didn't know by reading this thread. I was going to bury copper. Can you bury the black iron pipe?

Lee Schierer
09-15-2003, 1:16 PM
I believe that it is acceptable to use copper for Propane. Check with you gas supplier and they will know for sure.

Brad Schafer
09-15-2003, 2:53 PM
Don - I'm running propane thru buried copper with no trouble. Run flex copper a couple feet deep (to be safe) to a regulator, then black pipe off the back of the regulator.

BTW - we've had buried copper for a long time - one line was in almost 35 years; no trouble apart from having to blow it out a couple of times due to "dirty gas". Even with tree roots getting involved, there weren't any leaks.

I would think black pipe would rust like mad, and be hard as thunder to bury.

BTW - be careful with propane - it's heavier than air. Build-ups mean booms. A guy a few miles down the road wasn't - blew his woodshed halfway to Arkansas a few years ago on New Year's Day.


Richard Gillespie
09-27-2003, 9:30 PM
I'm retired from a natural gas distribution company. Be careful when ever you bury metal pipe directly in the ground. We experienced copper services developing leaks within six months of being installed in what turned out to be highly acidic soil. Uncoated steel and I don't mean painted can also rust out quickly under the right soil conditions. I had a electric conduit buried in the back yard rust out in one year.

Can't speak for all the company's but mine went to special compound plastic pipe for direct bury installations.

For in house piping black iron was used for low pressure carrier (8" w.c.) and hard copper was used for 2 pound systems. We used pipe dope not tape on all connections to black pipe.

I would recommend that you check local code before starting this kind of work.

leo raph
11-17-2005, 8:45 PM
I am running natural gas piping (3/4") to a pool heater outside (for a hottub). A plumber told me that I should use Black Iron on the inside and Galvanized on the outside run. But how do I join these two? I am worried that there will be a corrosive effect if the two touch.

Also, at what point do I switch between the two types? The outside wall is a 2 foot masonry wall (old house!). I know I'm supposed to use a plastic sleeve while running thru tha masonry. So should I change from black to galvanized immediately after getting to the outside?

Also, I understand that galvanized corrodes when exposed to natural gas... wouldn't it be better to use black iron outside then? and to just rust-paint it really well? My outside run is all above-ground.


Richard Gillespie
11-17-2005, 8:56 PM
I'm not an expert or licensed. I'm retired from a Natural Gas Distribution Company and have never used any other iron pipe but black pipe for both inside or outside installations. It is my impression that galvanized pipe was to be used for water installations and black pipe for natural gas. The only other installation I've been involved with was the 2# system with copper pipe used in some homes.

I hope this helps but in all honesty, I've been retired for over 10 years and things change.

Frank Hagan
11-17-2005, 9:33 PM
Here in California, they used to sell coated black iron pipe for burial use and outdoor exposure use for gas lines. See if your local store has that ... it was green in color, and had a thick coating on it ... almost like an epoxy coating (not sure what the actual material was).

They used to sell yellow PVC pipe for natural gas, but it could be buried only, and not used above ground at all. A special transition fitting has to be used to come above ground. Black iron pipe can be used, but should be wrapped (subject to local codes). There's no electrolysis between black iron pipe and galvanized pipe, but you can have galvanized flakes coming off the pipe and getting trapped in the appliance's gas valve. Home Depot and Lowes have all the fittings, etc. that you need to meet the local codes.

On Propane, it may be easier to get the local propane company to help you. Propane can use a two pressure system to help save money on longer runs. A higher pressure system might use 3/8" copper pipe from the tank to a second regulator, where it drops the pressure down to 11 - 14" water column, and then the pipe is increased in size to the 3/4 or 1" the appliance needs for the rest of the run.

You didn't say what the input BTU/hr rating of the pool heater is, but the instructions will have a chart showing how large the gas line needs to be (they should list both LP/Propane and Natural Gas). For instance, a 175,000 BTU/hr input heater running on natural gas needs a 1" gas line if it is within 1 to 100' of the meter. If you are running the line farther than 100', then the size of the gas line has to be increased to 1 1/4".

Joe Mioux
11-17-2005, 10:00 PM
Wow this is a revived old thread. Black pipe is normal around here but across the river (the Mississippi) one of the greenhouses I frequent used 2" copper.

Before you do anything, contact your NG gas company for recommendations. This is one area where you do not want to skirt rules and regs. They will also tell you other important stuff like size of pipe etc.