What are valves and their classifications

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The control of valves can adopt various transmission methods, such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electromagnetic-hydraulic, electro-hydraulic, pneumatic-hydraulic, spur gear, bevel gear drive, etc. Under the influence of pressure, temperature or other forms of sensing signals, it can act as required, or simply open or close without relying on sensing signals. The valve relies on the driving or automatic mechanism to make the opening and closing parts move up and down, slide, swing or rotate, thereby changing the size of its flow passage area to achieve its control function.

By working temperature

Ultra-low temperature valve: A valve used for medium working temperature t<-101℃.

(2) Normal temperature valve: A valve used for medium working temperatures ranging from -29℃ to t<120℃.

(3) Medium-temperature valve: A valve used for medium working temperatures ranging from 120℃ to 425℃.

(4) High-temperature valve: A valve used for media with a working temperature t>425℃.

By driving mode:

According to the driving mode, they can be classified into automatic valve type, power-driven valve type and manual valve type.

According to the nominal diameter

(1) Small bore valves: Valves with a nominal bore DN≤40mm.

(2) Medium bore valves: Valves with a nominal bore DN ranging from 50 to 300mm.

(3) Large diameter valves: Valves with a nominal diameter DN ranging from 350 to 1200mm.

(4) Extra-large diameter valves: Valves with a nominal diameter DN≥1400mm