The first type of automatic valve: a valve that acts by itself depending on the ability of the medium (liquid, gas). Such as check valves, safety valves, regulating valves, steam traps, pressure reducing valves, etc.
The second drive valve: a valve operated by manual, electric, hydraulic and pneumatic means. Such as gate valves, globe valves, throttle valves, butterfly valves, ball valves, plug valves, etc.
In addition, there are several valve classification methods:
A, according to the structural characteristics, according to the direction of movement of the closing piece relative to the valve seat, can be divided into:
1. truncated door shape: the closing piece moves along the center of the valve seat, as shown in figure1-1.
2. Gate shape: the closing piece moves along the center of the vertical valve seat, as shown in figure 1-2.
3. Cock and ball: The closing part is a plunger or ball, which rotates around its own center line, as shown in Figure 1-3.
4. Rotate the shape; The closing member rotates around the shaft outside the valve seat, as shown in figure 1-4.
5. Dish-shaped: the disc of the closing part rotates around the shaft in the valve seat, as shown in Figure 1-5.
6. Slide valve shape: the closing piece slides in the direction perpendicular to the channel, as shown in figure 1-6.
Second, according to the purpose, according to the purpose of different valves can be divided into:
1. opening and closing function: used to connect or cut off pipeline media, such as globe valves, gate valves, ball valves and butterfly valves.
2. Non-return purpose: used to prevent medium from flowing back, such as check valve.
3. Adjustment: used to adjust the pressure and flow of medium, such as regulating valve and reducing valve.
4. Distribution: used to change the flow direction of medium and distribute medium, such as three-way cock, distribution valve and slide valve.
5. Safety valve: When the medium pressure exceeds the specified value, it is used to discharge excess medium to ensure the pipeline system and installation.
Make safety preparations, such as safety valves and accident valves.
6. His special uses: such as steam traps, exhaust valves, sewage valves, etc.
Three, according to the driving mode, according to the different driving modes can be divided into:
1. Manual: with the help of handwheel, handle, lever or sprocket, etc. , driven by manpower, when the transmission torque is large, equipped with
Worm gear, gear and other deceleration devices.
2. Electric: Driven by a motor or other electric device.
3. Hydraulic: Driven by (water, oil).
4. Pneumatic; Driven by compressed air.
Four, according to the pressure, according to the nominal pressure of the valve can be divided into:
1. vacuum valve: absolute pressure
The water column represents pressure.
2. Low-pressure valves: valves with nominal pressure PN≤ 1.6Mpa (including steel valves with PN≤ 1.6MPa).
3. Medium pressure valve: a valve with a nominal pressure of PN 2.5-6.4 MPa.
4. High-pressure valve: a valve with a nominal pressure of PN 10.0-80.0 MPa.
5. Ultra-high pressure valves: valves with nominal pressure pn ≥100.0mpa. ..
Five, according to the temperature of the medium, according to the temperature of the valve working medium can be divided into:
1. Ordinary valves: Suitable for valves with medium temperature of -40℃ ~ 425℃.
2. High temperature valve: It is suitable for valves with medium temperature of 425℃ ~ 600℃.
3. Heat-resistant valves: Suitable for valves with medium temperature above 600℃.
4. Low temperature valve: it is suitable for valves with medium temperature of -40℃ ~- 150℃.
5. Ultra-low temperature valve: suitable for valves with medium temperature below-150℃.
Six, according to the nominal diameter, the valve according to the nominal diameter can be divided into:
1. Small caliber valve: valve with nominal diameter DN < 40mm.
2. Medium caliber valve: a valve with a nominal diameter of DN50~300mm.
3. Large-diameter valves: valves with nominal diameters of DN350~ 1200mm.
4. Extra-large-diameter valves: valves with nominal diameter dn ≥1400 mm. ..
Seven, according to the connection with the pipeline, according to the connection between the valve and the pipeline;
1. Flanged valve: a valve with a flange on the valve body and connected to the pipeline through the flange.
2. Threaded valve: a valve with internal thread or external thread in the valve body and threaded connection with the pipeline.
3. Welded connection valve: There is a welded joint on the valve body, and the valve is welded with the pipeline.
4. Clamp connection valve: a valve with a clamp on the valve body and connected to the pipeline through the clamp.
5. Valve connected with ferrule: a valve connected with pipeline through ferrule.