NPT pipe fittings are a type of threaded pipe fitting used to connect pipes and other components in plumbing and fluid transfer systems. The acronym NPT stands for National Pipe Thread, which is a standardized system of threads used in the United States for joining pipes and fittings.
NPT pipe fittings have tapered threads that are designed to create a tight seal between the fitting and the pipe. The taper angle of NPT threads is 1.7899 degrees, which allows the threads to interlock and create a seal when tightened. NPT threads are designed to be self-sealing and do not require the use of thread sealants or tape, although these may be used to further improve the seal.
NPT pipe fittings are commonly made of brass, stainless steel, or other materials that are compatible with the fluids being transferred. They come in a variety of shapes and sizes, including elbows, tees, crosses, reducers, and couplings, among others. NPT pipe fittings are used in a wide range of applications, including plumbing, HVAC systems, compressed air systems, and hydraulic systems.
It is important to ensure that NPT pipe fittings are properly installed and tightened to prevent leaks and ensure a reliable connection. Over-tightening NPT pipe fittings can damage the threads and compromise the seal, while under-tightening can result in leaks. It is also important to ensure that the materials used in NPT pipe fittings are compatible with the fluids being transferred, as incompatible materials can lead to corrosion, contamination, and other issues.