Teflon tape on steel tapered pipe threads is an excellent sealant IF......... you tighten the joint sufficiently and slowly enough to allow the teflon to flow. We use steel tapered pipe threads routinely to 15000 psi with no leak problems.
The problem with teflon tape joints in home plumbing is usualy that the joints are not made up tight enough or slowly enough. sometimes because you just can't get to the joint with a big enough wrench. sometimes because the "plumber" just doesn't realize how much torque it takes to seal.
To be fair to plumbers. Using teflon tape and properly torquing up each connection would greatly increase the time (and therefore cost) to do a job. It is much more cost effective to use dope and make up joints to a much lower torque.

: It is immaterial if you cannot get it to hold pressure and cannot find the leak, then you may have to disassemble and redo it anyway. I do not subscribe to using teflon tape on steel pipe threads since a friend did a large gas system and had to redo it because of multiple leaks.

: : : I had a gas line and meter installed and put together a gas distribution system. Unfortunately, I cannot get it to pressurize. It slowly leaks down in spite of all the soapy water on all the joints that show no discernible leaks. I have been told that it is because I used the wrong type of teflon tape - the white stuff which is gas permeable rather than the yellow "gas" stuff. I was also told that my installation would be rejected by the inspector anyway because of the use of the "wrong type of tape" and that I should tear the whole system apart and either use the yellow gas tape or, use a gas approved dope. Is this correct or is this Eagle Hardware fantasy?

• Re: teflon tape on black iron gas pipe Mike 12:32:17 6/19/100(1)
  • Re: teflon tape used around oil mike 07:46:27 02/19/02(0)