1. The difference in valve seat structure
There is a spring inside the valve seat of the ball valve. The sealing design of the valve seat makes it difficult for the scum in the medium to enter the valve seat.
The valve seat is in contact with the ball for a long time under the action of the spring. Therefore, when the valve is opened and closed, the valve seat has a certain scraping function, which can scrape the scum attached to the valve core, so the valve can be guaranteed for a long time.
2. Sealing performance
Especially in high temperature and high pressure applications, due to the selection of materials with the same thermal expansion coefficient for the valve seat, valve body and valve ball, the gas emergency shut-off valve and the valve seat with spring structure, when the valve is closed, there is a huge temperature difference and temperature The drop will not affect the operation of the valve, and the valve will not be locked. In high-temperature applications, the valve seat of the gate valve will shrink because the medium does not circulate and the temperature drops when the valve is closed, resulting in a large pressing force on the valve plate. When opening the valve again, a larger torque is required to overcome this pressing force, otherwise it will cause huge damage to the valve seat and affect the service life of the valve seat.
3. Itinerary difference
The stroke of the ball valve is angular stroke, so the installation space is small and the height is low. The stroke of the gate valve is a straight stroke, so the installation space is large and the height is high.
4. Differences between implementing agencies
Because the ball valve adopts a fixed ball design, the opening and closing torque value is small, and the actuator of the emergency shut-off valve is correspondingly small. Since the valve plate has a large pressing force on the valve seat, a large torque is required to overcome this large friction force. Therefore, the actuator needs to be equipped with a large pressure.
5. Differences in maintenance
Normally, maintenance is not required, especially the ball and valve seat. Due to the small wear, they generally do not need to be replaced within 5 years. The gate valve needs regular maintenance due to the large amount of wear of the valve seat.