Low temperature stop valve It refers to the valve whose closing member (disc) moves along the center line of valve seat. According to this movement of the disc, the change of the valve seat opening is in direct proportion to the stroke of the disc. Because the valve stem opening or closing stroke of this type of valve is relatively short, and has a very reliable cut-off function, and because the change of the valve seat opening is in direct proportion to the stroke of the valve disc, it is very suitable for flow adjustment. Therefore, this type of valve is very suitable for cutting off or regulating as well as throttling.

The stem axis of the low-temperature stop valve is perpendicular to the sealing surface of the valve seat. The valve rod has a relatively short opening or closing stroke and a very reliable cutting action, making this valve very suitable for cutting off, adjusting and throttling as a medium. Once the cryogenic stop valve is in the open state, there is no contact between its valve seat and the sealing surface of the valve disc, so the mechanical wear of its sealing surface is relatively small. Since the valve seat and disc of most stop valves are relatively easy to repair or replace the sealing elements, it is not necessary to remove the entire valve from the pipeline, which is very suitable for the occasion where the valve and pipeline are welded together. The flow direction of the medium has changed when passing through this type of valve, so the flow resistance of the stop valve is higher than that of other valves.

　　 Low temperature stop valve Features of:

(1) The structure is simpler than the gate valve, and the manufacturing and maintenance are more convenient.

(2) The sealing surface is not easy to wear and scratch, and has good sealing performance. There is no relative sliding between the valve disc and the valve body sealing surface when opening and closing, so the wear and scratch are not serious, the sealing performance is good, and the service life is long.

(3) When opening and closing, the valve disc travel is small, so the height of the stop valve is smaller than that of the gate valve, but the structural length is longer than that of the gate valve.

(4) The opening and closing torque is large, the opening and closing is laborious, and the opening and closing time is long.

(5) The fluid resistance is large, because the medium channel in the valve body is more tortuous, the fluid resistance is large, and the power consumption is large.

(6) When the nominal pressure of the medium flow direction PN ≤ 16MPa, it is generally downstream, and the medium flows upward from the lower direction of the valve disc; When the nominal pressure PN ≥ 20MPa, the reverse flow is generally adopted, and the medium flows down from the upper direction of the valve disc to increase the sealing element energy. When in use, the medium of the stop valve can only flow in one direction and cannot change the flow direction.

(7) The valve disc is often eroded when fully opened.

The commonly used stop valves include national standard stop valve, American standard stop valve, German standard stop valve, Japanese standard stop valve, bellows stop valve and low-temperature stop valve.