NPT Thread advice
NPT Thread advice
(OP)
Does anyone know the specific steps to using an American National Taper Pipe Thread (NPT?) Specifics would be helpful. e.g. how many wraps of teflon tape would I need, etc.
Thanks,
Dave
Thanks,
Dave





RE: NPT Thread advice
Wrap the teflon tape a couple of turns on the whole length of the thread. Take care to wrap the tape in the opposite direction of the thread. Example, you are going to turn the pipe fitting clockwise to install it, then wrap the teflon counter-clockwise to avoid the tape unwrapping.
Edson Campos
edsoncampos@earthlink.net
RE: NPT Thread advice
RE: NPT Thread advice
Sealing products are normally more effective, especially as they minimize the risk of contaminating the pipe.
prex
motori@xcalcsREMOVE.com
http://www.xcalcs.com
Online tools for structural design
RE: NPT Thread advice
Trust this is of some help to you.
regards
RE: NPT Thread advice
RE: NPT Thread advice
RE: NPT Thread advice
thanx alot
bye
RE: NPT Thread advice
RE: NPT Thread advice
RE: NPT Thread advice
This is from IPT's "Industrial Fasteners Handbook"
"The prime purpose of tape or dope is lubrication to allow thread surfaces to deform and mate without seizing or galling. Pipe dope also helps plug openings resulting from improper thread manufacture and in some cases acts as a sealant to prevent leakage of gases and liquids."
If the threads aren't lubricated, there will be excessive heat generated when making up the fitting. Even with lubrication (and not tightening too quickly), you can put your hand on the fitting that's just been wrenched on, and feel the temperature increase.
If tape/dope isn't applied (and properly) to male pipe threads before assembly, you'll have a lot of leakers.
RE: NPT Thread advice
on the pressures and medium being used with the
fittings. Grease fittings generally have low pressure
being applied and do not need to be sealed that well.
To teflon or not to teflon, that is the question.
Forgive the humor.
RE: NPT Thread advice
In water joints we do. Probably hydraulic joints are more accurated.
RE: NPT Thread advice
NPT may have a spiral leak path along the length of the thread, between the root on the internal thread, and the crest of the mating external thread. This requires a sealant be used.
NPTF will not require a sealant, however, assembly without a lubricant is prone to galling, especially with stainless steel or other nickel alloys. Thread sealant should be used not so much for leak prevention, as lubrication. System contamination can be an issue, so it sealant/lubricant should only be applied to male threads, and be kept back one or two threads from the end of the pipe.