NPT PIPE

NPT PIPE refers to the United States standard Taper Pipe thread connection pipe, "NPT" is the abbreviation of "National Pipe Taper", that is, the United States national standard taper pipe thread. It is a common thread standard for pipe connections, widely used in North America and some other countries and industries that adopt American standards. This thread has a certain taper, through the tight fit between the threads to achieve the connection and sealing of the pipe, to prevent fluid leakage.

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Thread characteristics
Taper: The taper of the NPT thread is 1:16, which means that the change in diameter per inch of length is 1/16 inch. The taper design enables the thread to gradually form a tight seal during the tightening process, improving the reliability of the connection.
Tooth Angle: The tooth Angle is 60°, which is designed to help thread processing and matching, while providing better bearing capacity and sealing performance.
Thread size: NPT thread has a variety of size specifications, common 1/8 inch, 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch, etc., different sizes are suitable for different pipe diameters and flow requirements of the pipe system.
Sealing principle
The seal of NPT thread itself mainly depends on the interference fit between threads and the deformation of the thread surface to achieve. In practical applications, in order to further improve the sealing performance, sealing materials such as sealing tape (raw material tape) or sealant are usually used. The sealing belt is generally wound on the thread, and when the thread is tightened, the sealing belt is squeezed and filled in the thread gap to prevent fluid leakage; The sealant is applied to the surface of the thread and forms a sealing layer after curing to enhance the sealing effect.
Application field
Industrial field: Widely used in chemical, petroleum, natural gas and other industrial pipeline systems, used to connect various valves, pipe fittings, equipment, etc., to transport a variety of liquid and gas media. For example, in oil production and refineries, NPT threaded pipes are used to connect oil pumps, tanks, heat exchangers and other equipment.
Water heating field: It is also more common in building water supply and drainage and heating systems, and is used to connect taps, valves, water pipes and other components. For example, the water pipe connection in the bathroom and kitchen in the family, many of them use NPT threads.
Pneumatic system: In the pneumatic control system, NPT threads are used to connect pneumatic components, such as cylinders, solenoid valves, gas pipes, etc., to ensure the normal delivery and control of compressed air.
Merits and demerits
advantage
Strong versatility: NPT is an internationally recognized standard thread, and the relevant pipe fittings and tools on the market are easy to obtain, easy to install and maintain.
Good sealing performance: Through the taper design and the combination of sealing materials, reliable sealing can be achieved in a certain pressure and temperature range.
Easy installation: No special installation equipment is required, just use an ordinary wrench and other tools to complete the pipe connection.
shortcoming
High installation requirements: the degree of screw tightening needs to be properly controlled, if it is over-tightened it may cause screw damage, and if it is under-tightened it may cause leakage problems.
Poor reuse: After multiple disassembly and installation, the surface of the thread is easy to wear, affecting the sealing performance, and may need to replace the sealing material or pipe fitting.