Original message
| rwm411
 |  "Fitting black iron piping"
, posted Tue 21 Feb 01:04  
My gas is shut off, it's cold, and I need to quickly learn some standards - and possibly laws - of removing old and installing some new gas pipes leading to my stove. I did fine in my very first pipe fitting attempt replacing some piping to the furnace. It had a union leak after/under its shutoff valve, and also figured it might be better to have a solid pipe running to the furnace valve rather than the flex hose going right by the firebox. (needed better "tee nipple" positioning) But when I called the utility company to check my work - ensure no impending death and collateral destruction; we found another small leak in a separate run leading out yonder to my kitchen stove - way before the shut-off valve. So, as you guessed, to stop that one gas leak the entire gas line had to be shut off...understandable, but I'm going to be a bit cold tonight - and will have to fix this when the store opens tomorrow to avoid frozen water pipes.
There are no unions between any elbows and tees (except right next to the furnace, stove and water heater. These are on vertical sections of piping, leading me to wonder if those compression unions are meant for vertical stretches only. The section of pipes where this new leak was found is in a roughly four-inch vertical drop without a union (previous furnace location, I'm guessing) after a section that (oddly enough) weaves above one and below another run of electrical conduit.
In my chat with the utility guy, he mentioned that there should be a union, and that I'd need to put one in. I didn't think about my question until after he had left... It would seem to me that a ground joint union between each directional change would/should be a standard - on horizontal AND vertical runs.
So my question is: can I safely cut out and replace both the longer horizontal runs into this problem area with union-joined horizontal runs into a 90 degree elbow - (eliminating this odd vertical drop and weave), or do I have to start taking pipe apart from the stove's union joint? (a long, bumpy road in this old house)
rwm411 - cold and eager to learn
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Replies:
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| Zzz
| "Re(1):Fitting black iron piping" , posted Mon 18 Dec 20:57
To add a little info here you must use pipe dope that is aproved for gas there are 2 kinds available. Personally I'd rip the stove line out and cap it for the time being then run a 5/8 copper line to it when the house warms up, all ya need is a flairing tool.
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| evildberg
| "Re(1):Fitting black iron piping" , posted Tue 21 Feb 11:37
I'm hesitant to answer your question because I think that if anyone is going to work with gas pipe they should be licenced but due to your circumstances I know where you are coming from since I have had to go out and fix many leaks after the gas company shut off a meter to a house or business. I don't quite understand exactly what piping scenario you have there just by reading what you have described. As to your querstion in reguards to weather or not you can put a union in a horizontal run versus a vertical run, it doesn't matter what orientation it is in weather veretical, horizontal, angle etc. The reason they have one near the apliance is that it is code, you have to have a way to take the piping apart to service, replace apliance and it isn't really possible (unless you really tried) to not put one there. You can cut the piping apart instead of going all the way back to a union and unthreading it backwards. If you do this, make sure gas is in fact off by checking it at the other end where the apliance is. Once you cut the line, now you have to redo it at least to some extent, if not all of it because now you can't join it anymore without it being re-threaded. Pipe must be schedule 40 black iron (not cast iron) fitting must be mallable iron not cast iron also. Cast isn't permited because it is porus and may leak slightly when a gas is used with it. Also cast is prone to cracks and will shatter when a force is applied to it where mallable steel will not. Unions must be mallable iron also. You will have to get pipe and if you don't have a threader you will have to go to you local hardware store or home center to have the pieces you need threaded once they are cut to length. Use a good quality pipe thread sealant on all threads. Wrench all joints very tightly. When you are completed, call the gas company out and have them check it and then check all joints with their testers or use a solution of dish detergant and water (50/50) to spray on all joints with a spray bottle to check for leaks. This may be something that a lot of people don't know but the gas company isn't licenced to work on the gas piping after the meter. That is why all they can do for you is leak check and shut off the gas to the meter if there is a leak. Also this is very important, you can't have any thread joints or mechanical joints in any concealed location, in other words where you can't get at them, it is illegal. If you are planning to conceal these joints with sheetrock or other means or they are concealed, call a contractor out to make these repairs. I think I have answered all of your questions. Good luck to you.
I AM NOT RESPOSIBLE FOR YOUR ACTIONS UNDER THESE CIRCUMSTANCES AND TAKE NO LIABILITY OR RESPOSIBILITY FOR YOUR ACTIONS, WORK OR INSTALATION OF PIPING, FITTINGS AND MATERIALS.
Union Pipefitter (service) Minneapolis MN local 539
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