I want to break into a natural gas line, black pipe, to add a valve. I’ll valve it off at the meter and turn the stove off to relieve the pressure in the pipe. Is is safe to then cut into the pipe with a sawsall? Could what ever gas is left lingering in the pipe be explosive from the sparks of cutting the pipe?
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Replies
Use a pipe cutter. Vibrating a gas line with a sawzall is never good for the fittings.
Is that like a tubing cutter on steroids? It's kind of a tight spot, close to a joist.
I use a angle grinder to stop the vibration - FWIW.
But then I use a propane torch to light cigarettes too.
Remodeling Contractor just on the other side of the Glass City
If you shut the gas off at the meter and disconnect it at the stove, you should be able to work on the line safely.
I question your use of a sawzall, however. How do you plan to make up the line after you hack it off?
I plan to unthread each end of the cut pipe and thread in shorter lengthes joined together with a union.
Ok, that should work - although you'll probably need at least one "custom" length threaded nipple.
I would still pass on the sawzall though. They can vibrate things pretty badly and you may cause problems in other joints. A hacksaw would be better if you have room to use it.
hacksaw it is. Thanks.
How you planning to tie-in? Recip. saw doesn't make a very user friendly cut.
Rich, you might want to double check if the union's a legal way to go. One area I was in would only allow one union in a pipe run, and that can get tricky. OTOH, if it's not going to be inspected, might not be an issue either.
Don K.
EJG Homes Renovations - New Construction - Rentals
You can use as many R/L ( right/left ) assemblys as you want in any area... Around here unions are not allowed period.... but you can still buy them at the hardware store .
james
Up here in Canada you can use unions, as many as you want I guess but they must be accessible.
roger
I noticed you're in SanFran, most of my commercial earthquake flexes have a union on one end or the other.
"Why do you hurt me when I do bad things to you?" My youngest son to his older brother
I would have to see a pic or your earthquake flexes... the ones we use here look much like a water riser... only cavet here is that we have to leave them accessable.
I hate R/L fittings but you got to do what you got to do... wish I could use Unions at accessable areas but that's not happening.. Hell we are not even allowed to use plastic/abs for DWV.. all cast or copper. I like hanging Iron but there are many times when I wish I could just use ABS/Plastic... like after hanging for 10hrs.....
james
Yes our earthquake flex's must be accessible, they are used to connect to the appliance & look very similar to water heater connectors ( braided stainless).
So in San Fran is the gas "hard piped" to each appliance, with no flex connectors allowed?
"Why do you hurt me when I do bad things to you?" My youngest son to his older brother
You can use a 6" flex connector at water heater connections as long as they are indoors and not subjected to mechanical damage... that part is subjective.
for furnaces etc no flex connector is allowed to pass thru the metal part of the heater but you can use them inside the unit.
flex connectors are allowed for other appliances like stove etc.
In the applicatoin you describe we are allowed to use flex, we can also use flex when transitioning to an area that is prone to movement / vibration....like when an item is mounted on a vibraiton dampening block.
so flex is allowed in a limited ammount of applicaitons but absolutely no three peice compression unions.
james
Are you required to have a whole house earthquake gas shutoff valve?.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Depends....
You do not have to put one as a matter of course but if you are making changes to over say 20% of an existing system or are adding on that much you have to install a gas breaker... all fresh installations require one as well.
If I am doing any work near the entrance I put one in... they are really not that expensive and if given the choice 90% of home owners want one installed.
james
Here in So Cal, there is what I have learned and called a Gas Union made up on a left right nipple, a left right coupling sold as a set. I have only seen it in a match set up. 3/4" pipe about 7" to 8" long. Many HD would not know it as a Gas union but may have it wrapped in shrink wrap. Maybe the old school hardware stores may also carry it. Furgisons should carry it.
Edited 12/29/2007 8:33 pm ET by TonyCz
Edited 12/29/2007 8:34 pm ET by TonyCz
Thats exactly what I am talking about ... Right / Left fitting which is a left/right thread nipple and coupling... see we are on the sme page,
I asked for one at desperado and was told that no such thing....
james
Well in almost 4 decades of gas fitting I have never seen or even heard of a left hand thread in gas piping. I'm not saying it isn't out there...............................somewhere. I 've used a left hand thread hooking up old cast iron radiators but that's plumbing.
roger
now you have seen one, top hit on google for " right left coupling".
james
Left/Right Nipple And Coupling Set
View ImageView Image
These have standard right-hand threads on one side & reverse (left-hand) threads on the other. These are generally used for gas piping, when unions are not allowed.
Phew! I'm glad I said "somewhere".
Thanks. I wouldn't have believed it if you hadn't posted it. I like to learn something every day.
In the Canadian Gas Code (old) 5.14.3 A pipe fitting containing both left and right hand threads, thread protector or running threads shall not be used.
roger
rodger,
We have some pretty funny plumbing rules in the city.. I hate installing those little buggers but I do see why there is a need for them.... My opinion is that they are overused in this jouristiction, many instances a union would be more than sufficient.
james
If you must saw it - don't overlook a jigsaw with a good metal cutting blade. Works faster than a handsaw and you can do it with no vibration at all.I used a jigsaw with a fine blade to cut some very tight corners 1/2 copper pipe - and had a clean enough cut to be able to solder on a new fitting.I use my jigsaw with metal cutting blades more than I use it for cutting wood. I haven't used my hacksaw in 5 years.Of course - it's a cordless jigsaw... (bosch 18volt - lots of balls)JT
I use sawzalls all the time, I prefer my portaband, but I understand not everyone has one ( I have 3) , if you're going to use a sawzall make sure the blade is new, has fine teeth, & make sure the guard stays in contact with the pipe.
OK I'm probably breaking every safety rule there is with this tidbit, but here it goes--- When cutting something I don't want to vibrate I hold the work with my left hand while my left thumb is on top of the guard applying pressure so the sawzall does not jump back from the work.
"Why do you hurt me when I do bad things to you?" My youngest son to his older brother
Is that why they call you "Ol' Four Fingers"?
I have 4 fingers on each hand & two thumbs ;-)
FWIW I did say on the back of the guard.
"Why do you hurt me when I do bad things to you?" My youngest son to his older brother
Bill -
I'm a lefty, so I use my right hand to support the work. If this is a safety issue, 99.9% of the people I've seen using a sawzall are a hazard. - lol
I suggested that Rich use a hacksaw because a recip saw can be a little tricky to use unless you use one quite a bit. The hacksaw is slower, but much more gentle on the piping. - lol
Others have mentioned possible code issues with unions and Rich should look into that. In any case, the union (and new valve) need to be accessible so that making up and testing the connections is as easy as possible.
He may also need to add some support at the union and valve. Those act as point loads and can create unwanted stresses in the piping if they're unsupported. (In my engineering days, I did some work on seismic supports of nuclear plant piping and gained a lot of understanding about how it all works.)
Unions are allowed in my location, but it must be accessible & there is a limit on how many can be used, but I can't recall the code off the top of my head.
When I say unions I am referring to the 3 piece ground joint style. A flange can be considered a union & we can put as many of those in as we want & the don't have to be accessible.
"Why do you hurt me when I do bad things to you?" My youngest son to his older brother