| 摘要 |
<p>A gate valve with inlet and outlet body portions with annular valve seats thereon and a gate assembly movable between open and closed positions between said body portions and carrying sealing rings in opposite faces therof adapted to be brought into sealing relationship with said valve seats when the valve is open and when the valve is closed. The body portions of the valve have a plurality of bolts passing therethrough which are adapted to threadably engage the sealing rings to uniformly draw the rings toward their respective valve seats to clamp a gasket structure between a ring and its seat in positive sealing relationship. The bolts are adapted to be withdrawn from the rings to permit the gate assembly to be moved between open and closed positions. The bolts have washers associated therewith which engage the gasket structure when the bolts are withdrawn from sealing rings to move the gasket structure out of contact with the gate assembly to prevent abrasion of the gasket structure when the gate assembly is moved. The gate assembly is held and guided by a frame which has a screw drive contained therein for moving the gate assembly. Indicators disposed exteriorly of the valve are actuated by permanent magnets carried by the gate assembly to indicate whether the valve is open or closed.</p> |
