Abstract: A gate valve having a non-yielding body with a gate accommodating chamber with flat, downwardly converging end seating surfaces about portions of a flow passage communication with the chamber and downwardly convergent side seating surfaces, a wedge-shaped relatively soft resilient gate with downwardly convergent end sealing surfaces to establish tight sealing and wedging engagement with the end seating surfaces and downwardly convergent side surfaces to establish wedging engagement with the side seating surfaces, the angle of said end surfaces being less accute than the angle of said side surfaces whereby forces directed laterally inwardly and resolved axially in the gate by the side walls is greater than axial forces generated by the end surfaces when the gate is urged down in the body and whereby the end surfaces are urged and held in conforming seated and sealed engagement by the laterally directed and axially resolved forces, and operating means carried by the body and engaging the gate to selectively mov