What is the difference in performance between butterfly valves and gate valves?
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2017-03-16
Gate valve refers to a valve that moves vertically along the axis of the channel and is mainly used to cut off the medium on the pipeline, i.e. fully open or fully closed. Generally, gate valves cannot be used to regulate flow. It can be suitable for low temperature and high pressure as well as high temperature and high pressure, and can be made of different materials according to the valve. However, gate valves are generally not used in pipelines that transport media such as mud.
Advantages: ① Low fluid resistance; ② The required torque for opening and closing is small; ③ It can be used on circular network pipelines where the medium flows in two directions, which means that the flow direction of the medium is not restricted; ④ When fully open, the sealing surface is less eroded by the working medium than the shut-off valve; ⑤ The body structure is relatively simple and the manufacturing process is good; ⑥ The structural length is relatively short.
Disadvantages: ① The overall size and opening height are relatively large, and the required installation space is also large; ② During the opening and closing process, the sealing surface is subject to relative friction and significant wear, even causing scratches at high temperatures; ③ Generally, gate valves have two sealing surfaces, which adds some difficulties to processing, grinding, and maintenance; ④ Long opening and closing time.
Butterfly valve is a type of valve that uses a disc type opening and closing element to rotate back and forth about 90 ° to open, close, and regulate the fluid channel.
Advantages: ① Simple structure, small volume, light weight, and low consumption, especially used in large-diameter valves; ② Quick opening and closing, low flow resistance coefficient; ③ It can be used for media with Suspended solids particles, and can also be used for powder and granular media according to the strength of the sealing surface. Suitable for bidirectional opening, closing, and adjustment of ventilation and dust removal pipelines, widely used in gas pipelines and waterways in metallurgical, light industry, power, petrochemical systems, etc.
Disadvantages: ① The flow adjustment range is not large, and when it reaches 30%, the flow will increase by over 95%. ② Due to the restriction of butterfly valve structure and sealing material, it is not suitable for high temperature and high pressure Plumbing. The general working temperature is below 300 ℃ and below PN40 (6-40). ③ The sealing performance is relatively poor compared to ball valves and globe valves, so it is used in places with low sealing requirements.
