In regards to pipes and tubing, NPT stands for national pipe thread. NPT is the American standard for threaded pipes and fittings regarding the tapered threads.
National Pipe Taper (aka: American National Standard Taper Pipe Thread)
NPT x NPT= (NPT)2 or N2P2T2
Called Briggs Standard AKA NPT and the other threads NOT normally used in plumbing is NFT and ASE threads
Full form of NPT is "National Pipe Thread"
No, NPT threads are not compatible with NPSM threads. A pipe with NPT threads tapers slightly, while an NPSM-threaded pipe does not taper.
npt, national pipe thread, is a standard for threads on a screw. I (not a plumber) don't believe "npt valve" makes sense , but probably refers to a valve which has npt threading. Yes, a NPT Valve would be a valve with pipe threads as opposed to a sweat valve which has solder connections. There are several other type of piping connections too.
North Korea is the only country to formally withdraw from the NPT.
Residential, not commercial.
yes
Poly vinyl Chloride.
Rev per minute
Male Branch Tee
Yes they are. Iran signed the NPT July 1st, 1968. It was ratified, and Iran has not withdrawn from the NPT.