vyv_cox
Well-known member
I use thin PTFE tape, with about a dozen turns on a ½" thread. This equates to 3 or 4 turns of thicker tape. My usual guideline is that the threads start to look rounded at the top, pretty much like in the clip on this page: http://norcal.swagelok.com/blog/bid/88017/Skill-Applying-PTFE-tape-to-tapered-pipe-threads
They also make it clear that it is only for tapered threads, so even though I use it on parallel threads, it isn't really right.
But yes, I probably use too much rather than too little
The standard introduced on the offshore oil platforms I was associated with limited the number of turns of thin tape to three, even on far larger pipework and joints than we use on boats. The reason was for exactly the one you are experiencing - joints unscrewing themselves too easily. That's the number I use to this day.
Edit: Read your link and I see they say two or three turns, although they claim theirs is thicker than the usual stuff.
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