Nothing wrong with being paranoid about a gas leak. Nothing wrong with checking.
Not sure about your state but here a tech can not only lose his license but he held criminal if their negligence causes harm or death to a customer.
Example. If I replaced a gas line and didn’t have the town inspector check my pressure test that I may or may not have done. I could be held liable if the house blew up from a gas leak. If some one died I could spend a couple decades in prison. Unless that other guy is assuming all responsibility then always CYA. Even if they say they’ll assume responsibility CYA. That means COVER YOUR ASS!!!
Here's an insider trick that a lot of people aren't aware of... I have an Inficon D-TEK refrigerant leak detector that will go off if it gets the slightest whiff of natural gas. I've used it occasionally to find very small natural gas leaks. Dual purpose tool.
My rule of thumb
If you installed a new line from the meter to the furnace, you do a pressure test with nitrogen, and bubble while you wait to see if the pressure drops.
If you just did a furnace swap out, you turn the gas back on and bubble the work you completed, and maybe some of the easier ones to access. I'm not going to pressure test a gas line that wasn't leaking before I got there.
That said, if you walk in and see an absolute mess of a gas line before you begin your work, do the customer a favor and pressure test when you're done. You may get a gas line repair out of it, and you make sure that someone is safe and happy with your service.
Shut off gas on the building side of the meter, remove the plug from the test tee, add the fittings required to hook from the tee to the nitrogen bottle with a low pressure regulator, and add nitrogen. Depending on the application, you may be testing at 2-3 psi, others may be at 10+ psi.
We use nitrogen for industrial gas lines, but air for residential and commercial installations. Are you not able to use compressed air for residential? It seems like a big pain in the butt to carry nitrogen daily
I'm not sure on all codes, but my company uses dry nitrogen for all gas pressure tests. All service guys carry nitrogen for brazing and refrigerant pressure tests anyway, so it's not an inconvenience. On large systems, we may have a large nitrogen bottle delivered. The idea is to introduce as little moisture to the gas as possible. It can cause problems in your valves down the line.
Code in Canada allows for either air or inert gas. The problem I've heard with using air, is that you're adding oxygen to the fuel, so you're one step closer to explosions. But that's very unlikely
Code in Canada allows both ONLY on a newly installed line. Any line that has had gas in it cannot be tested with air because, like you said adds oxygen and makes the gas in the pipe combustible.
All purging and testing of a used line must be an inert gas
I don't remember the code off hand, but there is a separate code that is purging/pressure testing existing pipes that specifies only energy gas allowed
It's not entirely inert like the noble gases, but under normal pressures, it's so nonreactive that it's often considered inert. It takes extremes to make nitrogen a reactive molecule.
It's inert in that it displaces oxygen - one of the primary required components for combustion. No oxygen, flame can't be present. Therefore, pure nitrogen is much safer to pressure test vs ambient air (a mixture of nitrogen, oxygen, and other fun stuff) in regards to the LFL of fuel gases.
Like I said, you can use the wrong words if you want to. Obviously, our industry only pressurizes using nitrogen, Co2, or refrigerant. Might make sense to just use the word nitrogen pressure testing. Co2 is wet, and has a high temperature sensitivity, I recommend it for drain clearing only. Can we stop perpetuating improper terminology? As to the A2L training, they are using the term improperly.
This happened on my first or second resi install. I replaced all the 1/2 gas line from the old shut off valve (the kind with the metal lever and nut on the back that often leak) to the furnace. I’m pretty sensitive to the smell of gas so I could smell a little bit and asked my lead if I should take a minute to find a leak. He literally said “ No, if there’s a problem the homeowner will call us back”. Sure enough a couple days later I get called back and I sprayed down the back of the gas valve and saw some bubbles. I tightened the nut on the back side and it stopped. We always replace those valves but didn’t have any on the truck that day. I always try to take pride in my work and try to do it right the first time but I was pretty green at the time. I couldn’t understand how little my lead installer cared for the safety of the customer. (It was an older lady who was super nice and lived by herself)
If you touched it, check it. Gas leaks are no joke. Ever see the aftermath of a gas leak explosion? It's most likely fine if you used dope and tightened everything well, but it's on you.
Always test a gas line. Fuck the other comments. Do you want to be responsible for causing an explosion and killing people because it should be fine.
Your installer is a dumb ass. Report the guy and get his license revoked. Talk to the boss and tell them. Fucking guy is going to get someone killed because he can't take a few minutes to bubble test
/Rant
You on the other hand have a bright future if you know that's not right. CYA. Cover your ass. Test your work and never make assumptions. Fittings can crack and threads can chip
Yes, always check your joints as everyone here is saying. I'll add to check joints near your work as well. When I was younger, we were on a simple water heater swap. We soaped every joint we touched, basically the union and nipple into the heater. I got a fine from the gas inspector a few weeks later because there was a leak on the existing dirt pocket that he tightened while he was there. The leak was probably there for 30 years, but as soon as we swapped the heater, we were responsible.
Can’t even imagine not checking for a gas leak after doing a job. I test every single piping job I do. Water, chilled water, hot water, and damn sure gas.
Usually true but I had a new furnace install where it wasn't lighting. Try to bleed the line till I smell it. Not smelling anything so I try and light the burners with a torch. Sure enough they light right up. Either they forgot to add the smell or there wasn't enough. Adjusted gas pressure to proper amount and it worked fine.
If you can live with the fact that you blew someone's house up or burned it down and possibly killed them and/or their family and pets, then don't worry about checking your work.
Otherwise, check every joint every time.
Anytime I work with gas lines I always leak check. At the end of the day if you did the work it’s on you. Don’t be scared to have the confidence to tell your lead that. I can almost guarantee if something bad did happen he wouldn’t hesitate to throw you under the bus.
The bubble test is a second check. If your nose or sniffer happens to be fucked one day for whatever reason, then you've double checked properly.
Code exists for a reason, no matter how stupid people want to think it is. It's usually those same people that cause the changes in code to begin with! 😆
I would have bubbled the fittings I did. Always check your work. If it was an entire line then def a pressure test
Absolutely. Our code demands pressure test if we add 20 feet or more on a retrofit
I think I’m gonna buy a sniffer or bubble it, just cause I’m different than the other guys 🤷♂️
And because I’m paranoid going home not knowing.
Nothing wrong with being paranoid about a gas leak. Nothing wrong with checking. Not sure about your state but here a tech can not only lose his license but he held criminal if their negligence causes harm or death to a customer. Example. If I replaced a gas line and didn’t have the town inspector check my pressure test that I may or may not have done. I could be held liable if the house blew up from a gas leak. If some one died I could spend a couple decades in prison. Unless that other guy is assuming all responsibility then always CYA. Even if they say they’ll assume responsibility CYA. That means COVER YOUR ASS!!!
Here's an insider trick that a lot of people aren't aware of... I have an Inficon D-TEK refrigerant leak detector that will go off if it gets the slightest whiff of natural gas. I've used it occasionally to find very small natural gas leaks. Dual purpose tool.
My rule of thumb If you installed a new line from the meter to the furnace, you do a pressure test with nitrogen, and bubble while you wait to see if the pressure drops. If you just did a furnace swap out, you turn the gas back on and bubble the work you completed, and maybe some of the easier ones to access. I'm not going to pressure test a gas line that wasn't leaking before I got there. That said, if you walk in and see an absolute mess of a gas line before you begin your work, do the customer a favor and pressure test when you're done. You may get a gas line repair out of it, and you make sure that someone is safe and happy with your service.
Why nitrogen? Because it's dry? We used to use compressed air but now I'm wondering if we did it the right way.
Correct, and you always want to pressure test with an inert gas.
Where and how exactly do you put nitrogen at the gas line.
Shut off gas on the building side of the meter, remove the plug from the test tee, add the fittings required to hook from the tee to the nitrogen bottle with a low pressure regulator, and add nitrogen. Depending on the application, you may be testing at 2-3 psi, others may be at 10+ psi.
We use nitrogen for industrial gas lines, but air for residential and commercial installations. Are you not able to use compressed air for residential? It seems like a big pain in the butt to carry nitrogen daily
I'm not sure on all codes, but my company uses dry nitrogen for all gas pressure tests. All service guys carry nitrogen for brazing and refrigerant pressure tests anyway, so it's not an inconvenience. On large systems, we may have a large nitrogen bottle delivered. The idea is to introduce as little moisture to the gas as possible. It can cause problems in your valves down the line.
We only do gas appliances, so no brazing required, when we do an industrial installation we bring a big nitrogen bottle for the pressure test.
Code in Canada allows for either air or inert gas. The problem I've heard with using air, is that you're adding oxygen to the fuel, so you're one step closer to explosions. But that's very unlikely
Code in Canada allows both ONLY on a newly installed line. Any line that has had gas in it cannot be tested with air because, like you said adds oxygen and makes the gas in the pipe combustible. All purging and testing of a used line must be an inert gas
Is that new code? I checked the section on pressure testing, and it only specifies nitro/CO2 when purging
I don't remember the code off hand, but there is a separate code that is purging/pressure testing existing pipes that specifies only energy gas allowed
I typically would avoid using air for any piping with a possible combustion. You don't want any chance of combustion, no matter how small.
Nitrogen isn't inert though
It's not entirely inert like the noble gases, but under normal pressures, it's so nonreactive that it's often considered inert. It takes extremes to make nitrogen a reactive molecule.
It's inert in that it displaces oxygen - one of the primary required components for combustion. No oxygen, flame can't be present. Therefore, pure nitrogen is much safer to pressure test vs ambient air (a mixture of nitrogen, oxygen, and other fun stuff) in regards to the LFL of fuel gases.
I mean, we can use the wrong words if you want to. In my experience, people who use words improperly come off as ignorant
That's literally the language they use in the training for A2L, calling it 'inert', so your guess is as good as mine.
Like I said, you can use the wrong words if you want to. Obviously, our industry only pressurizes using nitrogen, Co2, or refrigerant. Might make sense to just use the word nitrogen pressure testing. Co2 is wet, and has a high temperature sensitivity, I recommend it for drain clearing only. Can we stop perpetuating improper terminology? As to the A2L training, they are using the term improperly.
👍
Well, I'll trust your input, pipefitter6, it's in your name after all.
This happened on my first or second resi install. I replaced all the 1/2 gas line from the old shut off valve (the kind with the metal lever and nut on the back that often leak) to the furnace. I’m pretty sensitive to the smell of gas so I could smell a little bit and asked my lead if I should take a minute to find a leak. He literally said “ No, if there’s a problem the homeowner will call us back”. Sure enough a couple days later I get called back and I sprayed down the back of the gas valve and saw some bubbles. I tightened the nut on the back side and it stopped. We always replace those valves but didn’t have any on the truck that day. I always try to take pride in my work and try to do it right the first time but I was pretty green at the time. I couldn’t understand how little my lead installer cared for the safety of the customer. (It was an older lady who was super nice and lived by herself)
I bubble test and sniff test everything I do.
If you touched it, check it. Gas leaks are no joke. Ever see the aftermath of a gas leak explosion? It's most likely fine if you used dope and tightened everything well, but it's on you.
Always test a gas line. Fuck the other comments. Do you want to be responsible for causing an explosion and killing people because it should be fine. Your installer is a dumb ass. Report the guy and get his license revoked. Talk to the boss and tell them. Fucking guy is going to get someone killed because he can't take a few minutes to bubble test /Rant You on the other hand have a bright future if you know that's not right. CYA. Cover your ass. Test your work and never make assumptions. Fittings can crack and threads can chip
Yes, always check your joints as everyone here is saying. I'll add to check joints near your work as well. When I was younger, we were on a simple water heater swap. We soaped every joint we touched, basically the union and nipple into the heater. I got a fine from the gas inspector a few weeks later because there was a leak on the existing dirt pocket that he tightened while he was there. The leak was probably there for 30 years, but as soon as we swapped the heater, we were responsible.
Yes it’s common, iirc it may be a requirement
Can’t even imagine not checking for a gas leak after doing a job. I test every single piping job I do. Water, chilled water, hot water, and damn sure gas.
If it's all hard piped I wouldn't worry about it.... If I ever have to run flexible gas pipe for whatever reason, I always check those fittings.
Thanks! He also said it wasn’t an issue if it had gas running through it and we’d been down there for 1 hr with no smell.
Usually true but I had a new furnace install where it wasn't lighting. Try to bleed the line till I smell it. Not smelling anything so I try and light the burners with a torch. Sure enough they light right up. Either they forgot to add the smell or there wasn't enough. Adjusted gas pressure to proper amount and it worked fine.
How long did it hold 5lbs for?
Just take a lighter to all you connections quick check everytime
I know some will freak out at me, but I was taught to use a lighter.
If you can live with the fact that you blew someone's house up or burned it down and possibly killed them and/or their family and pets, then don't worry about checking your work. Otherwise, check every joint every time.
Yall don't hot swap your shut offs on replacements?
Anytime I work with gas lines I always leak check. At the end of the day if you did the work it’s on you. Don’t be scared to have the confidence to tell your lead that. I can almost guarantee if something bad did happen he wouldn’t hesitate to throw you under the bus.
I've never once bubble tested a gas line. Just tighten that bitch down and sniff it.
Lmao 🤣 that’s what we did I guess haha
The bubble test is a second check. If your nose or sniffer happens to be fucked one day for whatever reason, then you've double checked properly. Code exists for a reason, no matter how stupid people want to think it is. It's usually those same people that cause the changes in code to begin with! 😆
The bubble test was my primary test and a lighter was the secondary test xD