Tips on unscrewing gas line pipe fittings?

Question

I am installing gas logs in our fireplace and need to take off 2 elbow fittings that are stuck. I see the threads so I know they are screwed on, but can't get to budge.

Answer 1

What Joe said, but use two hammers instead of a wood block. Hold a large heavy hammer on the back of the fitting at the threads and hit the front of the fitting with a smaller hammer. That breaks the friction bond of the threads.

Answer 2

Gas Pipe Fittings

Answer 3

Gas Line Fittings

Answer 4

As a gas log installer for many years I found the best solution was to apply a liberal amount of "Liquid Wrench" to each fitting and let it sit for at least 1/2 hour before attempting to loosen fittings that were tough to undo. If this does not work, apply more Liquid Wrench and let it sit over night. Then apply more the next day and let it set for a 1/2 hour. Be sure to use 2 good sized pipe wrenches so you have a solid grip and good leverage. But, be careful not to apply too much pressure when turning the wrench as you can break the pipe at the threads. Instead, turn the wrench slowly applying a little more pressure at a time to see if the pipe will turn. Watch the fitting if it appears to be breaking loose to make sure it is actually unthreading instead of bending. If it is bending, then the fitting will most certainly break off. If this happens, you may need to contact a plumber to remove the pipe and rethread it, which can be quite costly...so you don't want to break it.



BTW: Gas line fittings in the USA are threaded just like any other pipe, they are not reverse threaded.



Also, you may NOT need to remove the last elbow as it sometimes makes it easier to install a gas log. If you leave the last elbow, you will need to screw a 1" nipple into it in order to attach the gas log fitting. I always had a bunch of them in my toolbox. So when you go to the hardware store to pick up your "Liquid Wrench", be sure to grab one.



Liquid Wrench comes in 2 forms; as a Penetrating Oil and a Lubricating Oil. Be sure to buy the Penetrating Oil. It comes in several bottled forms (drops and spray). I always used the dropper bottle because when I was installing gas logs that is all they had. The spray bottle comes with a small tube like WD-40 has and should work just fine.



Also, if your local hardware store does not carry Liquid Wrench, then WD-40 is a reasonable alternative, but it is more of a lubricant than a penetrate so it does not work nearly as well if the pipes are rusted. Use the resource below to see what Liquid Wrench looks like. If you have some liquid wrench on hand, go ahead and give it a try using the same instructions I gave for Liquid Wrench.



P.S. If you break the pipe a normal pipe threader will not work in the cramped space inside a fireplace. I have a DIY solution for rethreading it to save you from having to call a plumber. You'll have to email for the solution if this happens.



Also, if you seem to be having a hard time after trying my suggestions, email me some pictures of your fireplace and I may be able to offer you some other tips.

Answer 5

You need two pipe wrenches one to hold back on the pipe one to turn the fitting. your pipe wrenches should be at least 24" in size. Gas pipe are not left handed threads. So turn the fittings to the left. Remember right = tight left = loose. Sometimes if you put a wood block or hammer on one side of the fitting and smack the other side with a hammer that will help the loosing process. Go all around the fitting doing this if possible.

Answer 6

Use a quality pipe dope such as "LeakLock", "TrueBlue", or "BlueBlock" pipe dope. They are far superior to a lot of the common pipe dope. White Teflon should never be used because petroleum products, natural gas & propane will eat through it. There is a yellow "gas approved" Teflon tape that is available, but I'd steer clear of it. Make sure you clean the threads well (I use 1/2" fitting brushes) & use sufficient hangars to prevent it from moving. Inspectors in Massachusetts require 5psi for testing. Use 2 pipe wrenches (& hangars) to prevent fittings that had already been assembled from moving. Allow the joints to set for 15 minutes before applying air pressure. For 1/2" pipe, a 24" wrench is overkill. I'd use two 16" wrenches, but I could use 12"-24" if I didn't have them on the job. Make sure you don't apply more than 1/2 psi of pressure to the appliance or internal damage could occur.

Answer 7

The threads on gas fittings work in the opposite direction to normal threads (eg. water pipes) so you are probably tightening them instead of unscrewing them. So turn clockwise to unscrew.

Answer 8

different to uk, but try tightening first to break the seal,then unscrew