The essence of a pipe thread is a tapered thread. Its main function is to connect pipelines to ensure the smooth flow of media in the pipeline. From a structural point of view, pipe threads are divided into external threads and internal threads. The external thread is located on the outside of the pipe and cooperates with the internal thread to form a sealed connection. The internal thread is located inside the pipe and cooperates with the external thread to play a fixed role. Common pipe threads mainly include the following types: NPT, PT, G, etc.
The taper of the pipe thread determines the tightness of the connection. Generally speaking, the greater the taper, the tighter the connection. The angle of the thread affects the sealing performance.
NPT thread
NPT is the abbreviation of National (American) Pipe Thread, which is an American standard 60-degree tapered pipe thread and is used in North America. The tooth profile angle is 60 degrees and the taper is 1:16. NPT threads are divided into general sealing cylindrical pipe threads and general sealing conical pipe threads. The code for general sealing conical pipe threads in the American standard is NPT.
PT thread
PT is the abbreviation of Pipe Thread. It is the old code name for British sealed conical pipe thread, which belongs to the Whitworth thread family. PT thread is a 55-degree sealed tapered pipe thread with a 55-degree profile angle and a taper of 1:16. In Europe and the Commonwealth countries, PT threads are widely used in transportation pipelines, water and gas pipelines, lubricating oil pipelines, etc.
G thread
G is a 55-degree non-sealing pipe thread, which belongs to the Whitworth thread family. Marked G stands for cylindrical thread. This kind of thread is often used to transport low-pressure fluids, such as gas or water.
Pipe thread specifications and standards vary globally. These standards ensure the reliability of pipeline connections. At the same time, it also provides an important basis for global trade and technological exchanges.