Classification of valves

According to the working principle, role, according to the structure to divide:

Mainly divided into: gate valve, globe valve, check valve, ball valve, butterfly valve, plug valve, diaphragm valve, safety valve, steam trap, throttle valve and special valve.

By function:

 Cut off type: used to turn on or off the pipeline medium, such as cut-off valve, gate valve, ball valve, butterfly valve, plug valve, diaphragm valve.

 Non-return type: used to prevent media back flow, such as the check valve.

 adjustment type: used to adjust the medium pressure and flow, such as regulating valve, reducing valve, throttle valve

 Shunt: used to change the medium flow, distribution or diversion of media, such as three-way valve, steam trap, four-way valve.

 Safety: When the medium pressure exceeds the specified value, it is used to discharge the surplus medium to ensure the safety of piping system and , such as safety valve and accident valve.

 special purpose categories: such as vent valves, sewage valves and so on

By drive mode classification:

 Manual: With hand wheel, handle, lever or sprocket, driven by manpower, transmission of large torque, equipped with worm gear, gears and other deceleration devices.

Electrical: driven by a motor or other electrical device.

 Hydraulic: With (water, oil) to drive.

 Pneumatic: driven by compressed air.

 Electric hydraulic linkage, gas-liquid linkage.

By nominal pressure classification:

 vacuum valve: absolute pressure <0.1MPa of the valve, usually mm Hg column or mm water column pressure.

 Low-pressure valve: PN16 the following (including PN16) of the valve.

 Medium pressure valve: PN25 ~ PN63 valve.

 High pressure valve: PN100 ~ PN800 valve.

 High pressure valve: PN1000 above (including PN1000) of the valve.

According to the work of the valve medium temperature classification:

 ultra-low temperature valve: T < -101 ℃ of the valve;

 Cryogenic valve: -101 ℃ ≤ T <-29 ℃;

 Room temperature valve: -29 ℃ ≤ T ≤ 38 ℃;

 Medium temperature valve: 38 ℃ <T ≤ 425 ℃;

 High temperature valve: 425 ℃ <T ≤ 800 ℃;

 ultra-high temperature valve: T> 800 ℃.

According to the valve nominal diameter classification:

 Small diameter valve: Nominal diameter is less than or equal to DN40 valve.

 the diameter of the valve: DN50 ~ DN300 nominal diameter of the valve.

 Large diameter valve: DN350 ~ DN1200 nominal diameter of the valve.

 large diameter valves: DN1400 nominal diameter greater than or equal to the valve.

According to the connection with the pipeline classification:

 Flange connection valve: The valve body has the flange, and the pipeline uses the flange connection valve.

 Threaded valve: The valve body with internal or external thread, threaded connection with the pipeline valve.

 Welded connection valve: Valve body with welding groove, with the pipe connected with the welding valve.

Clamp connection valve: the valve body with a clip, and the pipe clamp connected to the valve.