Knowledge of all kinds of valves

1. Classification by function and use

Its medium is also called a block valve. Block valves include gate valves, globe valves, plug valves, ball valves, butterfly valves and diaphragms.

 

Check valve: check valve also known as one-way valve or check valve, its role is to prevent the medium flow back in the pipeline. Pump suction off the bottom valve also belongs to the check valve class.

 

Safety valve: the function of the safety valve is to prevent the medium pressure in the pipeline or device from exceeding the specified value, so as to achieve the purpose of safety protection.

 

4 regulating valve: the regulating valve includes regulating valve, throttle valve and pressure reducing valve. Its function is to regulate the pressure and flow of medium.

 

5 diverter valve: diverter valves include various distribution valves and drain valves, whose function is to distribute, separate or mix the medium in the pipeline.

 

Knowledge of all kinds of valves

2. Classification by nominal pressure

Vacuum valve: refers to the working pressure is lower than the standard atmospheric pressure valve.

 

2 low pressure valve: refers to the valve with nominal pressure PN ≤ 1.6Mpa.

 

3 medium pressure valve: refers to the valve with nominal pressure PN of 2.5, 4.0 and 6.4 MPa.

4 high pressure valve: refers to the valve whose nominal pressure PN is 10-80mpa.

 

5 ultra high pressure valve: refers to the valve with nominal pressure PN ≥ 100MPa.

3. Classification by operating temperature

1 ultra low temperature valve: used for medium working temperature T < - 100 ℃.

 

2 low temperature valve: used for medium working temperature - 100 ℃ ≤ t ≤ - 40 ℃.

 

3 normal temperature valve: used for medium working temperature - 40 ℃ ≤ t ≤ 120 ℃.

 

4 medium temperature valve: for medium working temperature 120 ℃

 

5 high temperature valve: for medium working temperature T > 450 ℃.

 

4. Classification by driving mode

Automatic valve is a valve that does not need external force to drive, but relies on the energy of medium itself to make the valve move. Such as safety valve, pressure reducing valve, drain valve, check valve, automatic control valve, etc.

 

2 power driven valve: the power driven valve can be driven by various power sources.

 

Electric valve: valve driven by electric power.

 

Pneumatic valve: valve driven by compressed air.

 

Hydraulic valve: with the help of oil and other liquid pressure driven valve.

 

In addition, there are the combination of the above several driving modes, such as pneumatic electric valve.

 

3 manual valve: manual valve with the help of hand wheel, handle, lever, chain wheel, manually operated valve action. When the valve opening and closing torque is large, the wheel or worm gear reducer can be set between the hand wheel and the valve stem. If necessary, the universal joint and transmission shaft can also be used for remote operation.

 

5. Classification by nominal diameter

1 small diameter valve: the valve with nominal diameter DN ≤ 40mm.

 

2-size valve: the valve with nominal diameter DN of 50-300 mm.

 

3 large diameter valve: the valve with nominal DN of 350-1200mm.

 

4 extra large diameter valve: the valve with nominal diameter DN ≥ 1400mm.

 

Knowledge of all kinds of valves

 

6. Classification according to structural characteristics

1 shut-off valve: the opening and closing parts (valve disc) are driven by the valve stem to make up and down movement along the center line of the valve seat;

 

2 plug valve: the opening and closing parts (gate valves) are driven by the valve stem and move vertically along the center line of the valve seat;

 

3 plug valve: the opening and closing parts (cone plug or ball) rotate around its own center line;

 

4 rotary valve: the opening and closing parts (valve disc) rotate around the axis outside the seat;

5 butterfly valve: the opening and closing parts (disc) rotate around the fixed shaft in the valve seat;

 

6 slide valve: the opening and closing parts slide in the direction perpendicular to the channel.

 

7. Classification by connection method

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

 

2 flange connection valve: the valve body has a flange, which is connected with the pipe flange.

 

3 welding connection valve: the valve body has welding groove, which is connected with pipeline by welding.

 

4 clamp connection valve: the valve body has a clamp mouth, which is connected with the pipe clamp.

 

5. Ferrule connection valve: it is connected with pipeline by ferrule.

 

6. Clamp connection valve: the connection form that the valve and the two end pipes are directly clamped together by bolts.

 

8. Classification by valve body material

1 metal material valve: its valve body and other parts are made of metal material. Such as cast iron valve, carbon steel valve, alloy steel valve, copper alloy valve, aluminum alloy valve, lead alloy valve, titanium alloy valve, Monel valve, etc.

 

2 non metallic material valve: its valve body and other parts are made of non-metallic material. Such as plastic valve, ceramic valve, lining valve, FRP valve, etc.

 

3 metal valve body lining valve: the valve body shape is metal, and the main surface inside contacting with medium is lining, such as rubber lined valve, plastic lined valve, ceramic lined valve, etc.