How to put an end cap on a gas pipe of a hot water heater.

[afjes_2016]

I helped my boss today install an electric hot water heater in replacement of a natural gas hot water heater in one of his rental units.

I did the electrical and he disconnected the gas heater and put the electric one in its place.

After we were finished and went home I realized that he should have put a cap on the end of the gas pipe where he cut it.

I don't know much about gas but would think an end cap would be good for safety.

He cut the black pipe that goes directly to the old hot water heater but he cut the pipe after the shut off valve. I guess the shut off valve would be good in not letting any gas escape but an end cap would be even better for safety.

If an end cap is needed or would be good what parts would be needed in order to install an end cap on the black pipe that has an end that is not threaded?

 

[Snoonyb]

Black Iron pipe is threaded, so remove the nipple and insert a plug.

Here's a variety; Threaded Pipe Plugs | Drain Plugs & Oil Plugs | G.L. Huyett

 

[bud16415]

It is the same as would you disconnect some wires and knowing the breaker is shut off not cap and terminate the wires at a minimum.

He shouldn't have cut the pipe it should have been taken apart the way it was installed and then capped. Where you are now I would go back to the gas valve and unscrew the pipe and plug it there. I would use a plug/cap and Teflon tape.

 

[afjes_2016]

Snoonyb and Bud - good idea!! Thanks!

Is the pipe a standard diameter usually? Like Pex, most of it is 1/2 that you would be working with.
I just don't know what size plug to tell him to order/get.

 

[bud16415]

.5 pipe is .840 OD .375 pipe is .675 OD

 

[Snoonyb]

Available @ "Ace is the place"; Search Results for Threaded pipe plugs - Ace Hardware

 

[afjes_2016]

Bud are you saying the pipe could be one of two different sizes?
Either .5 pipe is .840 OD or .375 pipe is .675 OD ?

I think it may be best for him to disconnect the pipe he cut and take it to HDepot. He should get a plug same size diameter as the threaded pipe end which will be a male plug.

 

[bud16415]

Bud are you saying the pipe could be one of two different sizes?
Either .5 pipe is .840 OD or .375 pipe is .675 OD ?

I think it may be best for him to disconnect the pipe he cut and take it to HDepot. He should get a plug same size diameter as the threaded pipe end which will be a male plug.

It is likely .5 pipe. you should be able to tell by eye.

 

[dsteinhorn]

If he cannot get to the threaded joint on old heater side of the shut off valve (because a stub is coming out of the wall, he can rent a manual pipe threader at a too rental house and put a thread on the end of the stub for a cap to cover it. Don't turn the pipe stub counterclockwise or you may loosen a hidden joint in the wall and let gas leak in the wall.

 

[Guzzle]

I helped my boss today install an electric hot water heater in replacement of a natural gas hot water heater in one of his rental units.

I did the electrical and he disconnected the gas heater and put the electric one in its place.

After we were finished and went home I realized that he should have put a cap on the end of the gas pipe where he cut it.

I don't know much about gas but would think an end cap would be good for safety.

He cut the black pipe that goes directly to the old hot water heater but he cut the pipe after the shut off valve. I guess the shut off valve would be good in not letting any gas escape but an end cap would be even better for safety.

If an end cap is needed or would be good what parts would be needed in order to install an end cap on the black pipe that has an end that is not threaded?

What's on your side is that the gas pressure is very low, but you want absolutely no leakage.
IMO, capping it is worth the extra time & mat'ls & shows Due Diligence.
In this case I guess the best leak detector is your nose, to pick up the odor of Mercaptan, but \/

"An odor threshold of 0.002 ppm has been reported for methyl mercaptan, but olfactory fatigue may occur and thus, it may not provide adequate warning of hazardous concentrations."

 

[billshack]

the gas code says you must closed the valve and install a cap or plug.

 

[afjes_2016]

After he plugs it I will tell him he should take some dish soap like Dawn, make a small mixture that and water and brush it over the connections to see if any bubbles start to form. It will make a mess but will be a good detector.