I have a Compression Union, which connects two pieces of pipes. One joint leaked, because nut loosed. I unscrewed the loosed nut, applied “pipe thread sealant”, then tightened the nut very tightly. The leak stopped about half an hour. Then leakage started again and water came out from the nut, although the leakage was much slower than before.

Any idea of how to fix this problem? Why the new leakage did not start immediately after I tightened the nut?

Thanks a lot.

zjclucky

Thanks a lot.

From Wikipedia, the free encyclopedia, I found the following:

"It is important to remember to not apply joint compound or teflon tape to a compression fitting's threads. The compression is the means of sealing the joint, not the sealing of the threads themselves. Pipe compound or teflon tape will frequently lead to a leak in the fitting by causing the fitting to loosen as a reaction to the compression."

Did the “pipe thread sealant”, which I put around the compression seat, caused the second leakage, which did not happen immediately after I tightened the nut? After I tightened the nut following the first big leakage, the leakage STOPPED FOR ABOUT HALF AN HOUR before it started again, although the second leakage was much slower than before.

Can the “pipe thread sealant” explain why the second leakage did not happen immediately after I tightened the nut?

Thank you very much.

KeepItSimpleStupid

Most people when they screw up, put the thread sealant or tape on the threads, you put it on the seat.

Some thread sealants do not harden and I suspect yours may have been one of them.

Pipe dope has fine particles of some material within a binder. When the water was turned on the pressure acted against the binder and forced it out. You were then left with the fine particles of the material. Now with small voids, water can leak out. It takes time and pressure to force the binder out.