Abstract: An assembly for retaining a seal ring in a seating surface of a valve is provided having a circumferential groove disposed in the seating surface for receiving the seal ring. The groove has a pair of substantially opposed side walls, one of which includes a first retention member extending into the groove. The opposite side wall is provided with a circumferential slot which is accessible from outside the valve sealing surface through a passage. A second circumferential retention member is inserted into the slot throughout the passage and protrudes into the groove such that both retention members cooperate to retain the seal ring within the seating surface.

Abstract: An assembly for retaining a seal ring in a seating surface of a valve is provided having a circumferential groove disposed in the seating surface for receiving the seal ring. The groove has a pair of substantially opposed side walls, one of which includes a first retention member extending into the groove. The opposite side wall is provided with a circumferential slot which is accessible from outside the valve sealing surface through a passage. A second circumferential retention member is inserted into the slot throughout the passage and protrudes into the groove such that both retention members cooperate to retain the seal ring within the seating surface.

Abstract: A sealing mechanism capable of use in a valve subject to extended temperatures and pressures. The sealing mechanism comprises a seal ring positioned within a groove circumferential with respect to the passageway of the valve. A convex seating portion of the seal ring extends through an annular opening in the groove, for sealing engagement with a closure member. Shoulder portions, which extend from the sides of the seating portion, abut the sidewalls of the groove. The seal ring is compressed in width within the groove, so that a resilient side-sealing force is imparted to the contact of the shoulder portions with the sidewalls of the groove. Substantially leak proof sealing is achieved, which is maintained even in the event of high temperature conditions or fire.

Abstract: An actuator for a rotary valve includes a fail-safe mechanism for automatically opening or closing the valve upon the occurrence of a predetermined condition. The actuator also includes a mechanism for permitting the manual operation of the valve from the open to closed position, and vice versa, and to a continuum of positions between the open and closed positions even when the fail-safe mechanism is activated. A biased clutch activates the fail-safe mechanism and also couples a worm-gear drive for effecting the manual operation of the valve.

Abstract: A bidirectional fluid flow control valve has two bifurcated elastic seat rings positioned in respective undercut grooves which are spaced apart in the flow passageway of the valve body, one on either side of the axis of rotation of a butterfly valve disc having two corresponding spaced apart annular sealing surfaces. One of the undercut seat grooves may be formed in a separate detachable seal ring to facilitate assembly of the disc in the valve. The valve disc is axially symmetrical with respect to its midplane, so that operating torque and flow characteristics of the valve are the same regardless of the direction of fluid flow through the valve.

Abstract: A valve seal mechanism for cryogenic applications includes an undercut groove in a seating region of the fluid passageway in a valve body. Disposed within the groove is a shouldered resilient wear ring of polytetrafluoroethylene, the outer circumference of the shouldered portion of the wear ring having a V-shaped channel formed therein. A solid backing ring having an inner circumferential surface of wedge-shaped cross section makes an interference fit with the V-channel of the wear ring, thereby preloading the channel sides against the respective adjacent sides of the groove. A valve disc has a sealing surface which makes an interference fit with a seating surface forming the inner circumferential surface of the wear ring. Introduction of fluid under pressure and reduction of temperatures from normal ambient to cryogenic both tend to increase sealing effectiveness.

Abstract: A power-driven quarter-turn valve actuator includes a reciprocating drive member in the form of a rod mounted perpendicularly to and spaced a preselected distance from a valve stem. A crank arm is coupled to the valve stem so that the axis of the crank arm makes an angle of between approximately 60.degree. and 100.degree. with a line intersecting the stem axis and perpendicular to the rod axis when the valve is shut and makes an angle of between minus 30.degree. and plus 10.degree. with said line when the valve is fully open. A link member connects the outer end of the crank arm to a point on the reciprocating rod. The preselected distance between actuator rod and valve stem, and the lengths of the crank arm and link, are chosen to produce a variable actuator torque output curve that closely matches the operating torque requirements of the valve.

Abstract: A valve seal mechanism for use in pressurized fluid systems subject to fire risk, the seal having a soft seat to provide essentially zero leakage at normal operating temperatures and a backup hard metal seating surface capable of holding leakage to extremely low rates in the event of temperatures high enough to destroy the soft seat material. The seal mechanism is in the form of a hard metal seal ring adapted to fit within an undercut circumferential groove in a valve seat. The metal seal ring has a central inner circumferential rib adapted to extend through the groove opening for mating engagement with a sealing surface on the circumference of a valve disc. The rib of the metal seal ring itself has a circumferential undercut groove into which is tightly fitted a seal ring of material softer than the metal of the seal ring, the soft seal ring protruding beyond the adjacent inner surface of the rib to provide a primary valve seat surface.

Abstract: A positive shut-off seal mechanism for use in pressurized fluid systems subject to high temperatures or fire risk. The seal mechanism includes a metallic valve seat in the form of an annular thin-walled skirt-like lip, preferably formed in a valve seat insert ring or retaining ring, the lip extending generally upstream toward the high pressure side of the valve. The edge of the lip engages a mating circumferential sealing surface of a valve disc, preferably at a location downstream from the plane of maximum disc diameter, with an interference fit to provide a preloaded radial sealing force between the edge of the lip and the sealing surface of the disc. The annular lip preferably forms the downstream side of an undercut groove for a resilient seal ring that provides a primary seal, the engagement of the lip edge with the sealing surface of the valve member providing a metal-to-metal backup seal in the event of damage to or destruction of the resilient seal ring.