Abstract: An expanding gate valve assembly which includes a gate, a stem for actuating the gate, a segment mounted on one side of the gate, or in an alternate, bidirectional embodiment, two segments with one segment movably mounted on each opposite side of the gate for movement toward seating surfaces within the valve body. Each segment carries two spaced, parallel wedging-camming surfaces which are of a configuration to cooperate with complementary spaced, parallel wedging-camming surfaces on the gate to effect lateral expansion of the segment or segments during closure or opening of the valve. The spacing of the wedging-camming surfaces or legs is such that the movable segments are stably supported during their expansion movement.

Abstract: An improved gate valve for high fluid pressure applications has a housing with aligned inlet and outlet passages and a well intercepting those passages. A piston-type gate is slidably positioned in the well and movable by conventional means between an open position wherein it does not intercept the inlet and outlet passages and a closed position wherein it blocks those passages and seats against the bottom of the well. The gate is fitted with a special seal which includes a circular section seated in a circumferential groove in the gate located above the inlet and outlet passages and a pair of lengthwise sections extending from diametrically opposite locations on the circular section toward the end of the gate at opposite sides thereof, those sections being located transversely with respect to the valve inlet and outlet passages.

Abstract: A single valve element disc and seat gate valve has an in-line flow passage therethrough. The valve seat plane is inclined approximately 5.degree. from the valve stem. First and second cam surfaces are positioned outside the flow passage, and are inclined approximately 30.degree. from the stem axis so that the cam surfaces and the valve seat plane define a wedge for receiving the valve disc and a hanger supporting the disc.The valve seat is a frustoconical surface. The valve disc is fixed to the hanger by means for urging the valve disc against the seat at the center thereof in a manner to ensure an effective seal therebetween. The gate valve includes a back seal for permitting the stem seal to be removed and replaced while the valve remains in service.

Abstract: A gate valve in which a threaded movable rod supports a cam that serves as a mounting for first and second floating valve plates that are disposed back to back, which valve plates when the cam is in a first position may be moved adjacent to first and second valve seats. The rod at all times has a portion thereof encircled by a cylindrical sleeve. The sleeve has at least one slot therein defined by first and second legs that are angularly disposed relative to one another. The sleeve also has guide means therein to prevent the first and second valve plates from pivoting from positions where they are substantially parallel to the first and second valve seats. A protuberance is secured to the rod and engages the slot. When the protuberance is in the first leg of the slot the first and second valve plates are in first positions and may be moved into and out of the path of flow of fluid through the valve.