There are many types of valves, and there are many classification methods. Here are a few.
1. Classified by purpose
(1) The cut-off valve is used to cut off or connect the medium. This function is commonly used. Such as gate valve, globe valve, plug valve, ball valve, butterfly valve, etc.
(2) Check valves are used to prevent the medium from flowing back. Such as check valve, bottom valve, etc.
(3) The diverter valve is used to control the change of the flow direction of the medium, and play the role of distribution, divergence, and merging. Such as three-way plug valve, four-way ball valve, distribution valve, etc.
(4) Regulating valves are used to adjust the flow and pressure of the medium. Such as regulating valve, pressure reducing valve, throttle valve and so on.
(5) Safety valves are used for pressure relief and discharge when the medium pressure or liquid level exceeds a certain value, to prevent the container or pipeline from overpressure, and play a safety and safety protection role. Such as safety valve, relief valve and so on.
(6) Separating medium valves are used to separate steam and water or water and air. Such as steam traps, air traps.
(7) Multi-purpose valves are used to replace two, three or more types of valves. Such as stop check valve, check ball valve and so on.
Type classification of valve
2. Classified by valve nominal pressure
(1) The vacuum valve is used for valves whose nominal pressure is lower than the standard atmospheric pressure (absolute pressure is lower than 0.1MPa).
(2) Low-pressure valve is used for valves with nominal pressure ≤ PN16.
(3) Medium-pressure valve is used for valves with nominal pressure> PN16 but ≤ PN100.
(4) High-pressure valves are used for valves with nominal pressure> PN100 but ≤ PN1000.
(5) Ultra-high pressure valve is used for valves with nominal pressure> PN1000.
3. Classified by valve nominal size
(1) Small-caliber valves are used for valves with a nominal size ≤ DN40.
(2) Medium-caliber valves are used for valves with a nominal size> DN40 but ≤ DN300.
(3) Large-caliber valves are used for valves with a nominal size> DN300 but ≤ DN12 00.
(4) Extra-large-caliber valves are used for valves with a nominal size ≤ DN1200.
4. Classified by medium temperature
(1) Cryogenic valve is used for valves with medium temperature T<-100℃.
(2) Cryogenic valve is used for valves with medium temperature T≥-100℃ but <-29℃.
(3) Normal temperature valve Used for valves with medium temperature T≥-29℃ but <120℃.
(4) Medium temperature valve For valves with medium temperature T＞120℃ but ≤425℃
(5) High-temperature valve Valves for medium temperature T>425℃
Type classification of valve
5. Classified by the way the valve is driven
(1) Automatic valve A valve that relies on the energy of the medium to act on its own. Such as check valves, traps, etc.
(2) Manual valves. Valves operated by humans, such as handwheels, handles, and wrenches. When a large torque needs to be transmitted, gears or worm gears can be used.
(3) Pneumatic valve A valve operated by compressed air.
(4) Hydraulic valve A valve operated by liquid (water, oil, etc.).
(5) Electric valve A valve operated by means of a motor, electromagnetic or other electrical devices.
(6) Linkage drive valves. Valves operated by electric-gas or electric-hydraulic combined drive operation.
6. General taxonomy
According to the function principle and structure of the valve, it is a common classification method at home and abroad. Generally, the valve is divided into gate valve, stop valve, plug valve, ball valve, butterfly valve, diaphragm valve, check valve, regulating valve, safety valve, reducer Pressure valve, steam trap, etc.