Ball Valve Sealing Performance
Jan 02, 2018
The electric ball valve has the characteristics of simple structure, small volume, light weight, large consumption of materials, small installation size, rapid switch, 90 ° reciprocating rotation and small driving torque. It is used to cut off, connect and adjust the medium in the pipeline. Good fluid control characteristics and closed sealing performance. Electric ball valve seat sealing performance is good, the use of PTFE and other elastic materials made of seals, the structure is easy to seal, and the ball valve sealing capacity increases with the media pressure increases.
Electric ball valve thrust bearing to reduce the stem friction torque, the stem can be long-term operation smooth and flexible; due to PTFE and other materials with good self-lubricating, and the ball friction loss is small, so the ball valve long life; Install the stem and stem head convex to prevent the stem discharge, such as fire caused by stem seal damage, convex and the valve body can also form a metal contact to ensure that the stem seal.
Electric ball valve working principle of the ball valve is as follows:
A. open the process
1. in the closed position, the ball by the valve stem of the mechanical pressure, pressed on the valve seat.
2. When the hand wheel is turned counterclockwise, the stem moves in the opposite direction, and its bottom corner plane releases the ball from the seat.
3. stem continues to ascend and interacts with the guide pin in the spiral groove of the stem so that the ball starts to rotate without friction.
4. until the fully open position, stem to the limit position, the ball rotation to fully open position.
B. close the process
1. turns off, turn the hand wheel clockwise, the stem begins to descend and the ball moves away from the seat.
2. continue to rotate the hand wheel, the stem is embedded in the spiral groove in the role of the guide pin, so that the stem and the ball at the same time 90 ° rotation.
3. is about to close, the sphere has been rotated 90 ° without contact with the valve seat.
4. The last few turns of the hand wheel, the corner of the stem at the bottom of the plane mechanical wedge to the compression of the ball, so that it is tightly pressed on the valve seat to achieve a complete seal.