American National Standard Pipe Thread standards, often called national pipe thread standards for short, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings. They include both tapered and straight thread series for various purposes including rigidity, pressure-tight sealing, or both. The various types are each named with a symbol and a full name; examples of the symbols include NPT, NPS, NPTF, NPSC, and others.
Threaded pipe has the advantages of easier assemble with no welding treatment, it is one major processing method in pipe production. Threading pipe ends use the corresponding coupling the pipe connected. Threaded connections required to connect high strength, good air tightness to prevent leakage of pipe breakage and transport medium. Steel wire in the car before the end usually after machining include: cutting, car cylindrical, boring, chamfering and face processing. These processes are generally a dedicated threading machines at once, and some can also be done on two machines. In order to ensure compliance with standards thread size, oil drill pipe using pipe threaded ends, factory various instruments required rigorous testing, test items include snails moment, tooth height, tooth, thread length, taper, tight moments and so on.
Threaded pipes can provide an effective seal for pipes transporting liquids, gases, steam, and hydraulic fluid.