Patent attributes
A control valve has a valve body and a flow control element preferably in the form of a disc, the valve body defining at least one inlet passage, the inlet passage culminating in an opening which is surrounded at least partially by a flow control surface, and the flow control element is so arranged as to be able to pass close to the flow control surface and across the opening to adjust the flow rate of at least one fluid which is caused to pass through the valve body, wherein the flow control element is constrained within the valve body by a stopping member, the stopping member being adapted to allow a positive clearance to exist between the flow control element and the flow control surface. The stopping member is preferably adjustable, allowing the positive clearance to be adjusted.