Introduction of several gate valves
Gate valves are the most widely used of all types of valves in modern industry. In such valves, a sluice like gate in the body moves vertically with the fluid between the matching seats to open or cut off the flow passage. It is used as a cut-off, and the whole flow passage is straight through at full opening, when the pressure loss of medium operation is minimal.
General type gate valves are generally suitable for work where frequent opening and closing is not required and the gate is kept fully open or fully closed. It is not suitable for regulating or throttling use. For high speed flow media, the gate can cause vibration of the valve under partial opening, which may damage the sealing surface of the gate and seat, while the throttling will make the gate subject to erosion by the medium.
- Wedge type single gate valve
(1) The structure is simpler than the flexible gate valve;
(2) at higher temperatures, sealing performance is not as good as elastic gate valve or double gate valve;
(3) suitable for easy coking of high temperature media.
- Flexible gate valve
It is a special type of wedge type single gate. Compared with wedge gate valve, the sealing performance is better at high temperature, and the gate is not easy to be stuck after being heated. It is suitable for steam, high temperature oil and oil gas and other media, and suitable for the position with frequent switch. Not suitable for easy coking medium.
- Double gate valve
(1) better sealing performance than wedge gate valve, such as sealing face Angle and valve seat not very accurate, still has a better sealing;
(2) after the wear of the sealing surface of the gate, the metal pad at the bottom of the spherical core can be used for thicker, generally there is no need to surfacing and grinding the sealing surface, this single gate, elastic gate is difficult to do.
(3) more parts than other forms of gate valves;
(4) in addition to applicable to the vapor, oil and other media, also suitable for the switch frequently and wear on the sealing surface of the media, not suitable for easy coking medium.
- Parallel gate valve
(1) Tightness is not as good as other forms of gate valves;
(2) Suitable for medium with low temperature and pressure;
(3) in addition to the two RAMS with fixed plates are not easy to fall off, where the RAMS fixed with lead wire are easy to fall off, the use is not reliable.
The processing and maintenance of the sealing surface of gate and valve seat is simpler than other forms of gate valves.