Structural characteristics of the valve closure member in accordance with the direction of the valve seat can be divided into: (1) gate-shaped cross-section: close member along the seat centers; such as the cut-off valve (2) tap and ball: closure member is a plunger or ball, rotating around the center line itself; if plug, ball (3) gate shaped: the closure of parts moving along the vertical seat centers; such as gate valves, gates and other (4) swing shape: Close the valve seat member...

（1）小通径阀门：公称通径DN≤40mm的阀门。 （2）中通径阀门：公称通径DN为50～300mm的阀门。 （3）大通径阀门：公称阀门DN为350～1200mm的阀门。 （4）特大通径阀门：公称通径DN≥1400mm的阀门

(1) ultra-low temperature valve: for medium temperature t

（1）超低温阀：用于介质工作温度 t

（1）真空阀：指工作压力低于标准大气压的阀门。 （2）低压阀：指公称压力PN ≤1.6Mpa 的阀门。 （3）中压阀：指公称压力PN 为2.5Mpa、4.0Mpa、6.4Mpa的阀门。 （4）高压阀：指公称压力PN 为10.0Mpa～80.0Mpa的阀门。 （5）超高压阀：指公称压力 PN≥100.0Mpa的阀门。

(1) Cut off: such as gate valves, globe valves, plug valves, ball valves, butterfly valves, needle valves, diaphragm valves, etc. Truncated type valve, also known as closed valves, globe valves, and its role is to connect or disconnect the line of media. Check valve, check valve leakage, also known as one-way valve or check valve, the check valve is a kind of automatic valves, its role is to prevent the line of medium back, to prevent reverse pump and drive motor, and a container medium . Pump...

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