Valves are classified by function and use

Valves are classified by function and use

(1) truncation: such as gate valve, globe valve, plug valve, ball valve, butterfly valve, needle valve, diaphragm valve, etc. Truncation valve, also known as closed valve, cut-off valve, its role is to connect or truncate the medium in the pipeline.

(2) check type: such as check valve, check valve is also known as check valve or check valve, check valve belongs to an automatic valve, its role is to prevent the pipeline medium backflow, prevent pump and drive motor reverse, and the leakage of container medium. Water pump suction off the bottom valve also belongs to the check valve.

(3) Safety: such as safety valve, explosion-proof valve, accident valve, etc. The function of safety valve is to prevent the medium pressure in pipeline or device from exceeding the specified value, so as to achieve the purpose of safety protection.

(4) regulation: such as regulating valve, throttle valve and pressure reducing valve, its role is to adjust the pressure of the medium, flow and other parameters.

(5) shunt type: such as distribution valve, three-way valve, trap. Its role is to distribute, separate or mix the medium in the pipeline.

(6) Special purposes: such as pigging valve, vent valve, sewage valve, exhaust valve, filter, etc. Exhaust valve is an indispensable auxiliary component in pipeline system, widely used in boiler, air conditioning, oil and gas, water supply and drainage pipeline. Often installed in the high point or elbow and other places, remove excess gas in the pipeline, improve the road use efficiency of the pipeline and reduce energy consumption.

Classified by nominal pressure

(1) Vacuum valve: refers to the valve whose working pressure is lower than standard atmospheric pressure.

(2) low pressure valve: refers to the nominal pressure PN ≤ 1.6mpa valve.

(3) medium pressure valve: refers to the nominal pressure PN is 2.5mpa, 4.0mpa, 6.4mpa valve.

(4) High pressure valve: refers to the valve whose working pressure PN is 10.0Mpa ~ 80.0Mpa.

(5) Ultra-high pressure valve: refers to the valve with nominal pressure PN≥ 100.0mpa.

(6) Filter: refers to valves with nominal pressure PN of 1.0mpa and 1.6mpa

Classified by operating temperature

(1) ultra-low temperature valve: for medium working temperature T <; -101℃ valve.

(2) low temperature valve: used for medium working temperature -101℃≤ T ≤-29℃ valve.

(3) normal temperature valve: used for medium working temperature -29℃< T <120℃ valve.

(4) medium temperature valve: used for medium working temperature 120℃≤ T ≤425℃ valve

(5) high temperature valve: used for medium working temperature T >425℃ valve.

Classified by drive mode

According to the driving mode, it is divided into automatic valves, power driven valves and manual valves:

(1) Automatic valve refers to the valve that does not need external force to drive, but relies on the energy of the medium itself to make the valve action. Such as safety valve, pressure reducing valve, trap, check valve, automatic control valve and so on.

(2) Power drive valve: power drive valve can use a variety of power sources to drive. Divided into electric valve, pneumatic valve, hydraulic valve and so on. Electric valve: Valve driven by electricity. Pneumatic valve: valve driven by compressed air. Hydraulic valve: Valve driven by the pressure of a liquid such as oil.

In addition, there are several combinations of the above driving methods, such as gas-electric valves.

(3) Manual valve: manual valve with the help of hand wheel, handle, lever, sprocket, by manpower to control the valve action. When the valve opening and closing torque is large, gear or worm gear reducer can be set between the handwheel and the valve stem. If necessary, universal joints and drive shafts can also be used for remote operation.

Classified by nominal size

(1) Small diameter valve: nominal diameter DN≤40mm valve.

(2) Medium diameter valve: nominal diameter DN of 50 ~ 300mm valve.

(3) Large diameter valve: nominal valve DN of 350 ~ 1200mm valve.

(4) Large diameter valve: nominal diameter DN≥1400mm valve.

Classification according to structural characteristics

The structural characteristics of the valve can be divided into:

(1) Intercept shape: the closing part moves along the center of the seat; Such as cut-off valve

(2) cock and ball: the closing part is a plunger or ball, revolving around its center line; Such as plug valves, ball valves

(3) gate shape: the closing part moves along the center of the vertical seat; Such as gate valves, gates, etc

(4) Swing shape: the closing parts revolve around the axis outside the seat; Such as swing check valve

(5) butterfly: the disc of the closing part rotates around the axis of the seat; Such as butterfly valve, butterfly check valve and so on

(6) Slide valve shape: the closing part slides in the direction perpendicular to the channel. Such as slide valve

Classification by connection method

(1) Threaded connection valve: valve body with internal thread or external thread, and pipe thread connection.

(2) Flanged connection valve: valve body with flanges, and pipe flange connection.

(3) Welding connection valve: valve body with welding groove, welding connection with the pipeline.

(4) Clamp connection valve: the valve body is connected with the pipe clamp with a clamp.

(5) Sleeve connection valve: sleeve connection with the pipeline.

(6) Clamp connection valve: bolt directly to the valve and the two ends of the pipe clamp together.