What's the consensus about using teflon tape on union threads. I know that it's the union o-ring that seals and not the threads but I've heard it said that the decreased friction on the threads allows the union to be tightened better which compresses the o-ring better which makes for a better seal. Also, it supposedly makes it easier to disassemble the unions when the time comes.
Teflon Tape on Union Threads?
- Thread starter kristof
- Start date
I suppose it might help a little, but I don't bother. A properly made union goes together and comes apart again very easily.
I used to use Teflon tape on galvanized unions and Dresser couplings as those would lock up due to corrosion. I have never done it with PVC. You can crack a PVC union nut by over-tightening with or without Teflon.
JasonLion said:
Can you tell me what constitutes a properly made union? I bought some unions to allow removal of my mpv, but I bought the glue in version. Do I need the screw in version? Never installed a union before so any pointers are appreciated!
For swimming pool use, you normally use "slip" style unions, which glue to the pipe.
Some of the super cheap unions can be slippery when you try to grab them, or have threads that bind up. A good union will have a large textured area where you grab to tighten or loosen it and will have threads that smooth and turn easily.
They are reasonably easy to install. The key thing is to make sure the two pieces of pipe that the union is connecting together line up well. If the two pieces of pipe meet at an angle, even a very slight angle, it will be difficult or impossible to get the union together properly.
Some of the super cheap unions can be slippery when you try to grab them, or have threads that bind up. A good union will have a large textured area where you grab to tighten or loosen it and will have threads that smooth and turn easily.
They are reasonably easy to install. The key thing is to make sure the two pieces of pipe that the union is connecting together line up well. If the two pieces of pipe meet at an angle, even a very slight angle, it will be difficult or impossible to get the union together properly.
A little silicone grease will make them easier to remove in the future and prevent seizure from chalking.
I'd recommend something similar to jack's lube as an anti-seize (if anything), i wouldn't use teflon tape in this situation.