SLIDVENTIL MED TRYCKAVLASTNINGSMEKANISM

摘要

A gate valve having an internal relief mechanism (36) comprises a movable valve disc (32) for blocking the main fluid passageway (30) through the valve body (14). The valve disc (32) is provided with a channel (40,42) providing communication between the valve bonnet cavity (34) and with the main fluid passageway (30). The pressure relief mechanism (36) is disposed in the channel (42) of the valve disc (32) and provides for fluid communication between the valve bonnet cavity (34) and the high pressure side of the main fluid passageway (30) such that the pressure in the valve bonnet cavity remains substantially equal to the fluid pressure in the main fluid passageway (30).