How tight should iron connections for gas line be?

[ChicagoDIY]

I recently had to install a shut off valve on a new gas line in my home. The line is near the floor so I put an elbow joint on the line, a 4” long pipe, and then the valve on top of that. I used pipe dope on all connections. My question is pretty general. I’m just curious if there is a consensus on how tight iron pipes need to be for a gas line after they’re hand tight? After hand tightening the elbow joint, I used a wrench to make another quarter turn so that the elbow pointed upright after realizing I wouldn’t be able to make another full turn without a longer wrench or using my body weight. I did the soapy water test and all connections seem to be good. Just a little paranoid that I should have attempted another full turn. Any advice or input is greatly appreciated.

 

[Sylvan]

My advice is to call a licensed plumber. My employees recently took a 12 HOUR class on gas piping and even though they all passed the tests given the master plumber still has to be on the job


Anyone who gives you advice is liable for anything that may go wrong

https://www.nytimes.com/2019/09/09/nyregion/east-village-gas-explosion-trial.html

 

[Sponsor]

 

[ChicagoDIY]

My advice is to call a licensed plumber. My employees recently took a 12 HOUR class on gas piping and even though they all passed the tests given the master plumber still has to be on the job


Anyone who gives you advice is liable for anything that may go wrong

https://www.nytimes.com/2019/09/09/nyregion/east-village-gas-explosion-trial.html

The gas line itself was installed by a licensed plumber during renovations earlier this year and was inspected by the city. I did not do that myself. It was capped until I was ready to install a gas dryer last week. I decided to install a shut off valve between the new line and the dryer hookup for added safety. Nothing remotely approaching what the article you included implies.

 

[Sylvan]

Good luck whatever you decide .

BUT the installing plumber should have installed a gas valve with a plug in it and when the appliance was to be connected the plug should be removed and the valve turned on

 

[Jeff H Young]

hand tite ( like with your bare hand) plus a quarter turn? sounds loose

 

[Jadnashua]

I would not be happy with 1/4-turn after hand tight. If the threads are made properly, you can make another turn (or at least close) but may need a bigger wrench. If you're using PTFE tape versus pipe dope, you might get a little leeway by an being careful about the wraps, but you do need to keep at least the minimum.

 

[Terry]

A soap test is a good idea. When someone says hand tight, we have no idea what that means. I always use either pliers with long handles or pipe wrenches.

Gas is pretty serious. I was in Hanford California one time visiting relatives and experienced a bad situation there. I picked up their motor home from the dealer that had just been working on it. I told them as I was picking it up that there was a bad gas leak. They told me that they had just worked on it and I was wrong. I told them I was a plumber, and there was indeed a gas leak. They didn't buy it. Smarter than me I guess.

I drive the motor home back to their place, and my father in-law tells me it's okay to sleep in it. I'm insistent that nobody is sleeping in a motor home with a gas leak. He proceeds to demonstrate that the gas is working fine by lighting up burners on the stove. I'm backing out the door as I'm expecting an explosion. By this time my brother in-law is between me and the door, and he drops the oven door down.
Boom!!!!
Flames explode by him as I stand in his shadow. He turns to me and now has curly singed hair and eyebrows. The flames had gone right by him and missed me. Now everything is on fire. I turn and hook the hose up, turn back and start to put the fire out. My brother in-law sees me having so much fun with the hose, that he wants it now. I tell him the carpets that are burning inside are toxic.
Don't breath the air inside.
Of course that's the first thing he does as he starts coughing and coughing. Gee..........what a surprise.

They wound up towing the motor home back to the dealer. I found somewhere else to sleep.

I passed by this motor home in Oregon November of 2020
I least the one I saw catch fire was at my in-laws and I was able to put a hose on it.

 

[Sylvan]

Terry the reason I never give advice to a "DIY" regarding how to with gas is if they ask how to they had better call an LMP /Gasfitter

HERE>>>>>>> " If you're using PTFE tape versus pipe dope, you might get a little leeway by an being careful about the wraps,"<<<<<<<<

I wonder what plumbing, NFPA 54, AGA allows white Teflon tape on gas??

Regarding "hand tight" apprentices were taught "Hand tight then 3-5 turns by a wrench while holding back" BUT some people make it up more then others and that is when feeling how tight it should be comes with experience

Too tight the fitting can split. too lose it will leak

If you're using PTFE tape versus pipe dope, you might get a little leeway by an being careful about the wraps,

They thought it only happens to other people

https://www.kcrg.com/2020/09/29/gas-leak-causes-explosion-in-dubuque-one-house-destroyed/

 

[Jadnashua]

Okay, so what is the yellow stuff made out of?

Polytetrafluoroethylene

oatey. comfor updates TECHNICAL SPECIFICATION: Oatey Yellow Gas Line Thread Seal Tape with Polytetrafluoroethylene (PTFE) is a thread sealing tape designed specifically for gas lines up to 1-²“ diameter.

 

[Jeff H Young]

Okay, so what is the yellow stuff made out of?

Polytetrafluoroethylene

oatey. comfor updates TECHNICAL SPECIFICATION: Oatey Yellow Gas Line Thread Seal Tape with Polytetrafluoroethylene (PTFE) is a thread sealing tape designed specifically for gas lines up to 1-²“ diameter.

Been here befor and spent hours researching but everyone feel free to do thier own verification. I see little diferance between aprooved for gas and those that are for reasons unknown unlisted they probebly havent paid someone off. Ive used plain white for decades mostly due to being ordered to do so, but when its my work and Im the boss I wont use it. I see white tape on my brandnew propane tanks . Many if not nearly all contractors ignore the code (or dont know better), Im not saying its right Im just giving my observation. In my small amount of study I have yet to find a single white tape that is aprooved for gas , but cant assume that none are, though suspicious if its white. and by the way no idea what the stuff is made out of though I call it teflon they could all be the same or slightly differant composition

 

[Jadnashua]

My point being, that the yellow stuff is made of the same material as the white, which is PTFE, and in the original post, I did not specify white or yellow. It appears to be somewhat thicker, which may take more wraps if you used white, but the yellow is approved, as long as the pipe diameter is within allowances, and they're made of exactly the same thing. Yes, pipe dope can be used on any diameter, and may be easier. It also doesn't last all that long in a tool box, where PTFE tape could last enons, so would be available when needed, and not dried out, as pipe dope can be.

I entirely agree, working with NG can be extremely dangerous, and taking shortcuts or making mistakes can be disastrous. But, it's not rocket science, either. It's best left to people trained in its use, but can be done if you understand what's needed and you check your work properly to verify. Knowing how to do that, is the problem. I had one neighbor that hired people to replace the bulbs in her table lamps...was afraid of them, and unwilling to learn or be shown. It takes all kinds. You cannot tell from the internet, though, who you're working with...so, it can get messy.

 

[Jeff H Young]

yes I think the yellow is thicker but there are others that are thick too and I think legal on gas . Some of this stuff I cant figure out why one thing is legal and another isnt but safer and keep you out of trouble to follow the spec than have inspector tell you tear it all out

 

[DIYorBust]

About as tight as you can get it with a 12 or 14 inch pipe wrench will probably be about right, depends a bit in pipe diameter. It should be well beyond hand tight, and if you're using the right size pipe wrench it will be hard to over tighten, but might be possible if you are very strong. Make sure to use a back wrench. Using megaloc or similar dope will do the job, better would be yellow gas ptfe tape plus dope, but the megaloc will work fine alone if the threads are in good shape. For one joint, tape and dope might be overkill since you can always tighten down a bit more if it leaks. I like to use a gas wand in addition to the soapy water test, sometimes i even catch a one the plumber missed. I also like to use gas test solution instead of soapy water. I think it makes more bubbles, and is easier to see. This is based in my own experience and is not specific advice professional or otherwise.

 

[Jeff H Young]

Id say DIYorbust is pretty close on 1/2 or 3/4 inch. Ive got my process and Ive worked on gobs of screwed pipe, factory nipples are almost always great threads. the 21 foot lenghths are about half the time ok , many arent great but useable . then there are the fittings again most are good but you find them with no threads sand holes etc. when you get in the real world of screwed pipe you are cutting and threading , suddenly the threads arent coming out good and you need production as a pro you gotta decide whether the threads are good enough visually inspect every thread and fitting. is it the cutting oil is bad ? need new dies ? or that crappy china pipe? I mean the oil is old as are the dies and machine, of cource the dies need adjusting as well. So this very simple process has many variables "perfect"
threads and fittings will hold test easy and people think how could they ever leak?
BTW I happened to be on Otay site yesterday and they had referance to white teflon tape being fine for gas and then went on to say they had yellow that was code approved. why being" fine" for gas is not approved dont know but thats what they said, I thought kind of weired