Cutting gas line???

Don Metzinger · Apr 8, 2007

I need to replace a on/off valve for gas logs in a fireplace. The valve is actually outside and is accessed by a rod from inside. The square nub on the valve is shot. There is no union above or below the valve. Is it possible to turn off the gas at the meter/valve on the opposite side of the house bout 40' away and cut the line to install a new valve and union? Is there a danger of explosion? Not sure if I can start at the logs and unthread all the sections to get back to the valve. Suggestions?

Leejosepho · Apr 8, 2007

You might live in an area where only a licensed professional is allowed to do the work, but yes, what you are asking about can certainly be done. Your gas would first need to be turned off right at the meter, then the pressure would need to be released somewhere (such as via fire right there in your fireplace until it goes out). At that point, and depending upon nearby elbows or other fittings, your pipe could be then cut (by non-sparking means) on one side of the valve and either replaced or re-threaded to allow for a new valve and a union (and possibly a nipple).

However, it is also possible that the stem of your existing valve could be replaced much more easily and for a lot less money. If I were you, I would at least have someone from the gas company take a professional look before doing anything on my own.

Sponsor · 2022-01-29T12:20:58-0800

Gary Swart · Apr 8, 2007

If you do shut the gas off at the meter to do the repair, when you turn the gas back on, it will take some time to bleed the air out of the line. Natural gas is not high pressure. Be sure to leak test everything with liquid dish washing soap before lighting the fire.

Don Metzinger · Apr 9, 2007

Thanks for the info. The pipe sits against the brick on the out side where the valve is so the is no way to use a rotating pipe cutter, it also faces in towards the hole from the inside for the rod that operates the valve so I can't take it apart and replace the insides. The only way I have of cutting the pipe would be with my recipicating saw. I may have to start inside at the logs and work back to the valve, several angles and sections of pipe. I am sure there wasn't any thought of ever having to repair or replace this when it was put in, one union would have made this a very simple job. The line runs through the ceiling of the basement both finished and unfinished areas with no unions. I have and alway use the testing solution for leaks. Thank you for your responses. - don

Got_Nailed · Apr 9, 2007

Where I live there is always peace of pipe on one side of the valve that is reveres threaded. But there is no way of knowing what your standards are where you live at.

They donâ€™t use a lot of unions. You canâ€™t use a union anywhere that might get covered up.

If you do cut the pipe will you be able to use a pipe wrench to retighten your fittings. It sounds like it is to close to the wall.

Don Metzinger · Apr 9, 2007

Thank for the tip, I'll look but I doubt that one pipe is reverse threaded. The part of the pipe with the valve is actualy on the out side of the brick chimney about a 1/4" from the brick. If I could just cut the pipe with my recip saw this would have been easy. - don

Cass · Apr 10, 2007

The union can only be placed on the fixture side of the shutoff, never the meter side.

Leejosepho · Apr 10, 2007

Cass said:
The union can only be placed on the fixture side of the shutoff, never the meter side.

Where our natural gas line comes in from the meter, there is a large union just inside the wall of our house, then there is a smaller union near the end of the line and right after the valve feeding our furnace. That is how things were when my wife and I got this place ...

Is that first union okay, or does it need to come out?

Jwray · Apr 11, 2007

I just ran across this thread and see you did not get a reply to your question. I see it's a little old, but in case you are still waiting for a reply I'll give it a shot.

(Oops, It's not that old. I was looking at your join date and not the post date

)

That first union just inside your house is probably OK. In saying that I'm assuming the meter is outside the house and the usual main shutoff valve is at the meter.

You always need to have a shutoff valve reasonably close upstream of the union. I'm sure there is a code defined distance for my "reasonably close", but I don't know what it is off the top of my head.

The idea is that you can shutoff the gas supply and not have a lot of residual gas leaking out if/when you need to disassemble the union.

Bob NH · Apr 11, 2007

don metzinger said:
I need to replace a on/off valve for gas logs in a fireplace. The valve is actually outside and is accessed by a rod from inside. The square nub on the valve is shot. There is no union above or below the valve. Is it possible to turn off the gas at the meter/valve on the opposite side of the house bout 40' away and cut the line to install a new valve and union? Is there a danger of explosion? Not sure if I can start at the logs and unthread all the sections to get back to the valve. Suggestions?

I would first try to use one of the super-duper repair epoxies that are on the market to try to put that handle on. You don't have a lot to lose and might avoid a lot of grief with the pipes.

Gary Swart · Apr 11, 2007

If I picture your problem correctly, you will not only need to cut the pipe, but you will have to thread one end of pipe you cut. Cutting new threads in a tight area is a major problem at best, but if the pipe end is not absolutely perfectly square, it become virtually impossible to get the dye started. It's a big hassle working with gas lines when you have to back sections of pipe out, but that may be your best solution (if the epoxy idea doesn't work). I have found that it is much easier to use the old fashioned pipe dope on the joints than to use tape. Especially if you are working with long pieces of pipe by yourself. Teflon tape if not put on just right, will often leak. Gob the paste on, cinch the joint tight with a big wrench, and it's rare to have a leak. (Never say never)

Leejosepho · Apr 11, 2007

jwray said:
That first union just inside your house is probably OK ...

The idea is that you can shutoff the gas supply and not have a lot of residual gas leaking out if/when you need to disassemble the union.

Well then, we are fine!

Thank you.

Markts30 · Apr 11, 2007

leejosepho said:
Well then, we are fine!

Thank you.

Here that would NOT be fine...
You cannot have the union on the building supply/shutoff anywhere but outside...

1994 UPC 1211.10
Where unions are necessary, left and right nipples and coupling shall be used. Ground-joint unions may be used at exposed fixture, appliance, or equipment connections and in exposed exterior locations immediately on the discharge side of a building shut off valve. Heavy duty flanged unions may be used in special cases, when first approved by the administrative authority. Bushings shall not be used in concealed locations....

Don Metzinger · Apr 11, 2007

Thanks for all the replies and info. This is a great site, I read it even when I don't have a question or problem. I am going to take out the 3- 4 sections from the logs to the bad valve and make up a replacement for the one with the valve in it. Will have to wait for a few days as we have a storm with rain and snow due here in the denver area tomrorrow. - don

Leejosepho · Apr 12, 2007

markts30 said:
Here that would NOT be fine...
You cannot have the union on the building supply/shutoff anywhere but outside...

Ah, thank you. In either case, that union will eventually come out anyway. My guess is that it was initially placed there when someone moved the kitchen many years ago and lazily cut-and-teed to run a line for the stove.

Cutting gas line???

Users who are viewing this thread

Don Metzinger

New Member

Leejosepho

DIY scratch-pad engineer

Sponsor

Paid Advertisement

Gary Swart

In the Trades

Don Metzinger

New Member

Got_Nailed

DIY Senior Member

Don Metzinger

New Member

Cass

Plumber

Leejosepho

DIY scratch-pad engineer

Jwray

New Member

Bob NH

In the Trades

Gary Swart

In the Trades

Leejosepho

DIY scratch-pad engineer

Markts30

Commercial Plumber

Don Metzinger

New Member

Leejosepho

DIY scratch-pad engineer

Similar threads