Abstract: A valve in which a member is movable within the valve body so as to open and close access to a passage within the valve, and, when the movable member is closing access to the passage within the valve, a sealing member is engaged between the movable member and an end wall of the passage. The sealing member is made of a flexible but non-resilient material, and elasticity is imparted by means of a resilient member which causes the non-resilient material to be forced into engagement with the end wall. Limits are set for relative movement of the end wall and the movable member to prevent damaging flexure of the non-resilient material.