The role of throttle type pneumatic valve flange and steel chemical industry standards

chemical type pneumatic valve:
open-close type: cut off or communication pipe fluid flow;
external regulation: adjust the flow rate, flow velocity;
the throttle type: after making the fluid through the pneumatic valve produces a lot of pressure drop; Other type:
a. Automatic opening and closing b. To maintain a certain pressure c. Vapor barrier drainage.
chemical pneumatic valve before use notice:
1) pneumatic valve inside and outside surface defects such as sand holes, cracks;
2. Pneumatic seat and aerodynamic body joint is rigid, it fits the pneumatic valve seat, pneumatic valve core sealing surface with and without defects;
(3) pneumatic valve rod connected to the pneumatic valve core is flexible and reliable, pneumatic valve stem is bent, thread is damaged;
steel flange chemical industry standard:
chemical engineering construction technical specifications' HGJ - HGJ - 】
chemical standards; The European system' HG- HG- 】
chemical standards; The European system' HG- HG- 】