Beginners of valves always mistake faucets for valves. Faucets strictly belong to the bathroom series. Valves are divided into gate valves, stop valves, butterfly valves, high-pressure valves, low-pressure valves, fluorine-lined valves, safety valves, pressure relief valves, anti-corrosion valves, filters, check valves, pressure-reducing valves, over-flow valves, ceramic valves, medium-pressure valves, high-temperature valves, low-temperature valves, etc.
- Classification by power
1. Automatic valves
Valves that rely on the power of the medium to operate. Such as check valves, pressure reducing valves, steam traps, safety valves, etc.
2. Drive valves
Valves that rely on external forces such as manpower, electricity, hydraulic power, and pneumatic power to operate. Such as stop valves, throttle valves, gate valves, butterfly valves, ball valves, plug valves, etc.
- Classification by structural characteristics
1. Gate shape: The closing part moves along the center line of the valve seat.
2. Gate shape: The closing part moves along the center line perpendicular to the valve seat.
3. Plug type: The closing part is a plunger or a ball, which rotates around its center line.
4. Swing type: The closing part rotates around an axis outside the valve seat.
5. Disc type: The closing part is a disc, which rotates around the axis inside the valve seat.
6 Sliding valve type: The closing part slides in a direction perpendicular to the channel.
- According to the purpose
1. Opening and closing: used to cut off or connect the pipeline medium. Such as stop valve, gate valve, ball valve, plug valve, etc.
2. Adjustment: used to adjust the pressure or flow of the medium. Such as pressure reducing valves, and regulating valves.
3. Distribution: used to change the flow direction of the medium and play a distribution role. Such as three-way plug, three-way stop valve, etc.
4. Check: used to prevent the medium from flowing back. Such as check valves.
5. Safety: When the medium pressure exceeds the specified value, discharge excess medium to ensure the safety of the equipment. Such as safety valves, and accident valves.
6. Gas blocking and drainage: retain gas and remove condensate. Such as steam traps.
- Classification by operation method
1. Manual valve: valve operated by hand with the help of handwheel, handle, lever, sprocket, gear, worm gear, etc.
2. Electric valve: valve operated by electricity.
3. Pneumatic valve: valve operated by compressed air.
4. Hydraulic valve: valve operated by transmitting external force with the help of liquids such as water and oil.
- Classification by pressure
1. Vacuum valve: valve with absolute pressure less than 1 kg/cm2.
2. Low pressure valve: valve with nominal pressure less than 16 kg/cm2.
3. Medium pressure valve: valve with nominal pressure of 25-64 kg/cm2.
4. High pressure valve: valve with nominal pressure of 100-800 kg/ccm2.
5. Ultra-high pressure: valve with nominal pressure reaching or exceeding 1000 kg/cm2.
- Classification by medium temperature
1. Ordinary valve: valve suitable for medium working temperature of -40 to 450℃.
2. High temperature valve: valves suitable for medium working temperatures of 450 to 600℃.
3. Heat-resistant valve: valves suitable for medium working temperatures above 600℃.
4. Low temperature valve: valves suitable for medium working temperatures of -40 to -70℃.
5. Deep cold valve: valves suitable for medium working temperatures of -70 to -196℃.
6. Ultra-low temperature valve: valves suitable for medium working temperature below -196℃.
- Classification by nominal diameter
1. Small diameter valve: valves with a nominal diameter of less than 40 mm.
2. Medium diameter valve: valves with a nominal diameter of 50 to 300 mm.
3. Large diameter valve: valves with a nominal diameter of 350 to 1200 mm.
4. Extra-large diameter valve: valves with a nominal diameter greater than 1400 mm.
The above classification is not absolute, and it can also be classified from other angles, but mastering these basic classifications is of great benefit to our understanding of the wide variety of valves.