standard for number of turns of teflon tape
standard for number of turns of teflon tape
(OP)
Are there standards for a minimum or/and maximum turns of teflon tape on a give NPT thread. In my company we use 1.5 to 2 turns, but not sure.
TIA,
Alfonso Del Toro
TIA,
Alfonso Del Toro





RE: standard for number of turns of teflon tape
I like 4 turns. 2 just don't do. With 2 turns, it was too difficult to get drip-free. I started doing 4 turns, reasoning that there would be more tape-on-tape meshing. It works for me.
RE: standard for number of turns of teflon tape
RE: standard for number of turns of teflon tape
RE: standard for number of turns of teflon tape
RE: standard for number of turns of teflon tape
Tape or dope is required to fill the spiral clearance between the crests and roots of pipe threads, as well as lubricate them. Unless you're using Dryseal NPTF threads (which require special taps & dies to cut them), you need sealant. I've never actually seen NPTF threaded pipe/fittingss or taps/dies. These threads are much more precise, and the crests and roots meet, to eliminate the spiral clearance. Lubrication is still advisable, especially with stainless steel.
RE: standard for number of turns of teflon tape
However, it has been my experience that a good quality pipe dope works better than cheap Teflon tape.
RE: standard for number of turns of teflon tape
RE: standard for number of turns of teflon tape
Most Loctite products are not rated for service over 300*F, which effectively eliminates them for steam service.
RE: standard for number of turns of teflon tape
Starting at the tip or far end, I put an overlap of about half the width of the tape between successive wraps over the full length of engagement. My tendancy is to have a lot of tension on the tape itself, often it breaks so I need to start over again. But once at the top end, I repeat to go downwards to the point of starting.
This way, the tape doesn't unwrap as you're torquing the plug. There is no correct way, everyone is different.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: standard for number of turns of teflon tape
Consider Teflon paste in lieu of or addition to the tape.
John
RE: standard for number of turns of teflon tape