How many turns to tighten pipe thread fittings

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Vdawg

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Putting some FIP Dahl stop valves onto brass MIP threaded adapters (to PEX-A). I notice when I screw the valve onto the fitting it goes on about 3 turns before it gets hand tight without tape or thread sealant (not ready for final assembly -- just testing to see if the threading is good on both parts). I'm guessing a pair of wrenches and some teflon tape will get me maybe one more full turn... Still a lot of thread showing on the male adapter. Is that normal? Should it thread in more deeply or is it normal to have about half the threads exposed on the male adapter when completely assembled? I've double-checked the labels for thread type -- both pipe thread so I assume they are compatible and meant to work together. :)
 

Terry

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There is no such thing as hand tight plus "so many turns"
They tighten until it "feels" right and doesn't leak. And there is no rule about how many threads are left showing.
 

John Gayewski

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3 to 5 threads showing is usually what I find, and I've never (knock on wood) had a leak on pipe i threaded and assembled. But in reality the 3 to 5 is variable. There are some products that tighten up quick from the factory. Some not as much. I can tell you that if you have buried all of the threads it's too loose or you've gone way overboard.

The more you do it the more you just know.
 
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