GATE VALVE, METHOD FOR RETURNED DRILLING MUD PRESSURE CONTROL AND/OR WELL KILLING, AND USES OF A GATE VALVE

摘要

The present invention relates to a gate valve (10), in particular for returned drilling mud pressure control and/or well killing. The gate valve comprises: a flow passage (14); and a gate member (22) movable for intersecting the flow passage. The gate member includes a gate port (28) which extends from one face (34a) to an opposite face (34b) of the gate member and is alignable with the flow passage for allowing material in the flow passage to pass through the gate member, and a groove or recess (30) is provided in an inner wall (32) of the gate port, the groove or recess extending from the one face to the opposite face of the gate member. The present invention further relates to a method for returned drilling mud pressure control and/or well killing, and uses of a gate valve.