The gate valve is a cut-off valve, and its sealing performance is not as good as that of the shut-off valve. The main "responsibility" of the gate valve is to "cut off the flow" and minimize the resistance. When the gate valve is fully open, the whole flow channel is through. At this time, the pressure loss of the medium is the least. Its main advantage is that the fluid flow resistance is small. The flow resistance coefficient of ordinary gate valves is about 0.08~0.12. The gate valve is usually suitable for conditions that do not need to be opened and closed frequently, and the gate is kept fully open or closed, which is not suitable for adjustment. If it is used for long-term adjustment, the sealing surface is easy to be washed and worn by the medium, which will affect the sealing performance. 

 Attention should be paid to the reliability of the medium temperature and pressure of the gate valve. 

 When the gate valve is opened and closed, the valve core and the sealing surface of the valve seat are always in contact and rub against each other, so the sealing surface is easy to wear, especially when the valve is close to close, the pressure difference between the front and rear of the valve core is large, and the wear of the sealing surface is more serious; the sealing surface of the gate valve has a certain self-sealing ability, and its core relies on the pressure of the medium tightly Contact with the sealing surface of the valve seat to achieve tightness and no leakage. The spool slope of the wedge gate valve is generally 3~6 degrees. When the core is forcibly closed with excessive or large temperature changes, it is easy to get stuck. Therefore, high-temperature and high-pressure wedge gate valves have taken certain structural measures to prevent the valve core from jamming. 

 When the gate valve is fully open, the whole flow channel is through. At this time, the pressure loss of the medium is the least. Its main advantage is that the fluid flow resistance is small. The flow resistance coefficient of ordinary gate valves is about 0.08~0.12. The gate valve is usually suitable for conditions that do not need to be opened and closed frequently, and the gate is kept fully open or closed, which is not suitable for adjustment. Section, thratting use.