What NPT thread means
NPT, national pipe taper, is the standard tapered thread on pipe and fittings in North America. The taper makes the joint tighten as it seals.
Also called national pipe thread, tapered thread.
Where it matters on a plumbing job
Mixing NPT with straight threads, such as hose or compression threads, causes leaks that no amount of tape fixes. Check the thread type on every adapter.
Work it out
- Licensing: Plumbing license rules by state
- Tools, templates and guides: Free plumbing resources