Ball valve is a commonly used type of valve, consisting of four parts: valve body, valve ball, valve seat, and valve ball. The main function of a ball valve is to achieve switching and flow regulation in pipelines. On ball valves, there are often letters printed, such as "FNPT", "NPT", "SW", etc., which represent some meanings. This article will introduce the meanings of these letters.
1: What is FNPT valve
FNPT is the abbreviation for Full National Pipe Thread, which stands for National General Pipe Thread in the United States. This thread form is a common way of connecting pipe fittings, and its threads can be matched to achieve sealing and connection.
2: What is NPT valve
NPT stands for National Pipe Thread and is one of the American pipe thread standards. The difference between it and FNPT is that FNPT has female threads, which are protruding threads, while NPT has male threads, which are recessed threads.
3: What is SW valve
SW stands for Socket Weld, which is a welding method. The SW mark on the ball valve indicates that it is connected to the pipeline in this way, which has the advantages of good sealing and strength.
4: What is BW valve
BW stands for Butt Welding, which is also a welding method. The BW mark on the ball valve indicates that it is connected to the pipeline using this welding method. Compared with SW, BW's connection method is more secure and suitable for pipelines with high pressure resistance.
5: What is RF valve
RF stands for Raised Face, which refers to the protrusion on the flange of a ball valve. RF type flanges have good sealing and stability, and are commonly used in high-pressure pipeline systems.
6: What is RTJ valve
RTJ stands for Ring Type Joint, which refers to the flange gasket of RTJ ball valves. RTJ type gaskets have good sealing performance and are suitable for high temperature and high pressure media.
7: What is FXF valve
FxF is the abbreviation for Female x Female, indicating that both ends of the ball valve have internal threads and need to be used in conjunction with corresponding fittings.
8: What is MxF valve
MxF is the abbreviation for Male x Female, which means that one end of the ball valve is externally threaded and the other end is internally threaded, and it needs to be used in conjunction with the matching fittings.
9: What is ISO valve
The two commonly used forms of ISO for vacuum flanges are ISO-K and ISO-F. Manufacturing standards include DIN 28404 and ISO 1609, which can be applied in situations requiring a vacuum degree of up to 10-8 mbar. Flange sealing materials are usually Viton, Buna, Silicone, EPDM, aluminum wire, etc. Flanges are usually made of 304, 316 stainless steel, etc. Common ones include ISO high vacuum ball valves A and ISO-K vacuum joints, which are usually composed of flanges, flange claws, O-ring seals, and centering rings. B. ISO-F vacuum joints are usually composed of flanges, O-rings, and centering rings. Unlike ISO-K, the flanges are sturdy with bolts.
9: What is KF valve
KF flange, O-Ring, centering bracket, and clamp for distribution. No need to use other tools, simply twist the disc nut by hand to loosen or tighten the connection. Mainly used in high vacuum systems. The specifications range from KF10-KF50, and the size of the pipeline connected to KF is usually relative to the inch specification. The pipeline corresponding to KF25 is 25.4 * 1.65mm, and so on (some require special pipelines, and the welding size of flanges can be customized). The vacuum connection from KF to KF50 (with piping of 50.8 * 1.65mm) is the ISO series.
The above are the meanings of common English letter terms for valve connection methods. Understanding these letters is of great help for selecting and using ball valves correctly.