For a pipe fitting, what does the term "NPT" refer to?

The term "NPT" stands for National Pipe Thread. This designation describes a specific type of thread used primarily in piping applications for joining cylindrical pipe sections. National Pipe Threads are standardized, providing a reliable method for creating tight seals between pipes, fittings, and valves, ensuring they can handle pressures without leakage.

Understanding NPT is crucial for pipefitters because it defines the angle, pitch, and dimensions of the threads, which are essential for ensuring compatibility between different pipe components. Often, NPT threads are tapered, which means they become narrower as they get further away from the end of the pipe, enhancing the seal as the connections are tightened. This can lead to a more secure and leak-proof joint in various applications, making it a foundational concept in pipe fitting and plumbing.