It's real important to apply your Teflon tape in a clockwise direction which coincidentally is the same way you thread on most of your fittings.. If you apply the tape in an anticlockwise direction it will unravel as you screw on the fitting which will render it useless. To apply , this is what l find the easiest.
You apply the tape to the threads in the opposite direction you will be threading on, making sure to keep the tape tight as you wrap it.
same as steel you just don't need it on brass and of course plastic fittings
yes
Many fittings, except unions, require the use of teflon tape.
Yes, but only if it is necessary.
You do not need tape on any flared fitting, brake or regular. The brake line and the fittings are different size and thread type than regular copper line and fittings. You can't mix them.
No, teflon tape (and pipe dope, for that matter) should never be used on flare fittings. They are designed to seal without tape or dope, and may actually leak if tape or dope is used.
Not necessary, but recommended along with pipe thread compound.
Pipe dope better solution than tape.
Teflon tape only, no joint compound. Two or three wraps is plenty... Yes agreed, teflon tape will make it easier for repairs in the future
Possibly if you an apply an etcher first to prime the surface. There are a few glues that are made by Loctite that will adhere to teflon.
NPT is a standard for threaded pipe and fittings. NPT stands for national pipe thread. NPT fittings are tapered thread fitting and usually rely on mechanical deformation in between the male and female fittings to create a seal in addition with teflon tape. Over tighteting may result in a leakage SAE O-ring fittings are straight fittings and rely on the O-ring to create the seal rather than deformation as in NPT fittings. Since these fittings do not depend on deformation chances of a broken fitting are virtually eliminated.
No, Teflon or polymerized tetrafluoroethylene is very very inert and in fact has to be apply by molding the shape you want out of powder much like sintering in metallurgy or forcing it into a porous surface.
Taape or joint compound on the threads the same as any other pipe fitting, but not on the threads where the two halves connect.