Abstract: A swing check valve for controlling fluid flow, including a valve housing having a port for fluid flow therethrough with a removable cover for accessing an interior of the valve housing. A valve assembly is positioned within the interior of the valve housing for controlling the fluid flow through the valve housing. The valve assembly includes a valve seat in fluid communication with the port and a clapper mounted in the valve housing on a pivotally-mounted rocker arm and moveable between an open position responsive to fluid flow in a flow direction and a closed position sealed against the valve seat responsive to fluid flow in an opposite, backflow direction. A spring is captured in the valve housing by the removable cover without attachment to either the cover or valve housing, and normally urges the clapper into the closed position sealed against the valve seat.

Abstract: A fluid pressure sealing assembly 40 adapted for bi-directional sealing of the annulus between two coaxially disposed cylindrical surfaces 16, 48 and including a stack of packing rings 41 sandwiched between a pair of retainer rings 43, 45. The packing assembly is held together by a plurality of pins 80, each of which extends through aligned openings in the packing rings 41 and into blind bores 81, 82 in the respective retainer rings 43, 45 on both sides of the packing rings. The surface of a retainer ring at each end of the sealing assembly 40 which is to be exposed to fluid pressure in the annulus is of greater area than the surface contact area of the adjacent packing ring 41 contacting the retainer ring because of the cross-sectional area of the pin holes so that the force which is transmitted to the packing rings from a retainer ring is amplified and increases the packing and sealing effect of the packing rings. Means 53 for mechanically applying a pre-load to the sealing assembly 40 may also be included.

Abstract: An improved heat responsive backseat for gate valves which includes a rotating valve stem (50) carried by a bonnet assembly (14) for actuation of a gate member (40). A fusible stem ring (126) supports the valve stem at an outer portion thereof (68) within a roller bearing chamber (56) of the bonnet assembly. The valve stem (50) moves axially outward from the valve chamber (20) when the fusible stem ring (126) melts due to an external fire condition to bring a valve stem backseat portion (64) into sealing engagement with a bonnet seat portion (54). The valve stem (50) moves axially outward from the valve chamber (20) independently of roller bearings (74, 76) contained within roller bearing chamber (56) such that the roller bearings (74, 76) remain axially fixed with respect to the bonnet assembly before, during and after the shifting of the valve stem.

Abstract: A high pressure sealing connection for sealing between coaxially aligned members (22, 10) which are connected by metal bolt means having a different coefficient of thermal expansion from the aligned members. The connection comprises a metallic sealing ring (40) having at its largest external diameter a curved arcuate peripheral surface 52 characterized by a center of curvature which is co-diametral with the center of the seal ring but may be of greater or lesser radius than the radius of the ring. At its inner periphery, upper and lower flanges (61, 62) extend inwardly and perpendicularly to the axis of the ring. The coaxially aligned members (22, 10) are provided with recesses defined by opposed internal frusto-conical sealing surfaces (41, 42) at their adjoining ends, each tapering inwardly from the end of the member to an annular shoulder (43, 44) in the bore of the aligned member. The frusto-conical surfaces (41, 42) are of equal taper in the range of 5 degrees to 20 degrees.

Abstract: A "fire-resistant" packing arrangement (30) for use with linear motion or rotary motion shafts (20) characterized by a stepped dual diameter packing chamber provided by successive enlargements of the stem bore (22). A primary packing assembly (31) disposed in the chamber section (20b) of smaller diameter and cross-sectional areas and located nearest the fluid pressure provides for sealing under normal temperature and operating conditions. A secondary packing assembly (32) in the larger diameter chamber section (20c) and fabricated of "high temperature" materials is adapted to maintain sealing effectiveness in the event of abnormally high temperatures.

Abstract: A valve (10) having an expansible gate assemblage of ported juxtaposed gate and segment members (18, 19) which are movable into sealing engagement with upstream and downstream valve seats (28) about the flow passage (12, 14) in the open and closed conditions of the valve wherein the valve includes pressure relief means which relieves excessive pressure in the valve chamber (11) into the upstream flow passage (12) when the environment in the chamber reaches a preselected temperature with the valve retaining capability of providing an upstream seal in the event of subsequent downstream leakage. The pressure relief means is installed in the segment member (19) of the gate assembly and comprises a passage (43) extending from the port (16) through the segment to the sealing face (25) of the segment member at a location which is exposed to the upstream flow passage (12) in the valve closed condition.

Abstract: An expanding gate valve with a valve seat structure which comprises a pair of "floating" seat rings (60) loosely received in annular seat pockets (52) surrounding the flow passage through the valve and each having an axial dimension which exceeds the depth of the seat pocket. The front face (61) of each seat ring is disposed adjacent the gate assembly (24, 26) and is provided with an annular groove (63) and an annular resilient sealing element (64) therein adapted to form a ring of sealing contact area about the flow passage (14) when the gate assembly is expanded thereagainst. The rear face (66) of the seat ring (60) is provided with an annular groove (63') and a second annular resilient sealing element (64'). The two annular sealing elements are coaxial and the inner diameter of the front sealing element (64) exceeds that of the rear sealing element (64') so that the front sealing element is a greater radial distance from the flow passage (14) than is the rear sealing element.

Abstract: A valve having a back-sealing capability provided by a pressure energizable sealing assembly which becomes operative independently of valve stem movement and valve element position for sealing between the valve casing (10, 22) and the valve stem (21) in the event of loss of sealing by the valve stem packing (33). A sealing ring (45) of the sealing assembly is installed with limited axial movement in an enlargement (20a) of the valve stem bore located intermediate the valve stem packing (33) and the valve chamber (11). The sealing ring (45) is provided with inner peripheral sealing surfaces (54) and an outer peripheral sealing surface (51) conforming in configuration to that of a corresponding sealing surface (42) provided in the stem bore enlargement.

Abstract: A pressure energizable packing assembly (47) for sealing the stem and valve body of a high pressure valve. The assembly comprises one or more sets (60, 61) of packing rings (62) which are adapted to be compressed between a pair of retainer rings (64, 65) and radially expanded into sealing engagement with the valve stem (45) and valve body (11). The retainer rings are actuated by Belleville springs (70) in a preloaded condition of the assembly and additionally by fluid pressure in the valve body after installation. The packing assembly includes an adapter ring plug (71) for accommodating its connection in the valve body. The packing assembly is assembled as a cartridge and held together by screws (77) which extend through the adapter ring (71), the outer retainer ring (64), the packing ring sets (60, 61) and their separating spacer ring (63), and which are anchored in the inner retainer ring (65).

Abstract: A packing assembly (10) for sealing the annulus between concentric tubular members (12, 14). The assembly (10) includes upper and lower sealing ring assemblies (31, 32) on each side of a lantern ring (33), and upper and lower retainer rings (36, 35) located atop and below the sealing ring assemblies and bolted together to maintain the rings in stacked concentric relation. Each sealing ring assembly (31, 32) includes a central lubricating packing ring (34) having inner and outer lubricating surfaces of graphite material; an inner pair of upper and lower metal seal rings (69, 70) seated in annular grooves in the central lubricating packing ring (34); and an outer pair of upper and lower metal seal rings (83, 84) located in annular grooves in the outer periphery of the lubricating packing ring (34).

Abstract: A packing assembly for a valve stem, or the like, comprising two groups of "V"-shaped packing rings, "G" and "H", disposed about the valve stem 16 in a stuffing box 32 provided in the stem receiving bore in the vavve body or bonnet 12. Semi-fluid plastic material 69 is injected between the two groups of packing rings to move them apart and thereby axially compress and radially expand the packing rings into sealing engagement with the valve stem and stuffing box wall. The lower group of packing rings is provided with a pair of non-metallic back up adapter rings at its lower and upper ends. A similar back up adapter ring is provided at the top of the upper group of packing rings. The back up adapter rings 61, 62, 68 serve to stabilize the packing structure. They also serve as stem centralizing rings to preclude galling and scarring of the stem and as anti-extrusion rings to impede extrusion of the packing rings along the stem and bonnet.

Abstract: A gate valve (10) has an expanding gate assembly (34) for reciprocal movement transversely of the flow passage (16, 18). The expanding gate assembly (34) includes a gate element (68) and complementary segment (70) which expand away from each other when the gate assembly (34) is in either a fully open or closed position. A spring (92) is anchored to a side (87) of the gate element (68) and extends over and engages a pair of spaced apart lugs (88, 90) on the adjacent side (91) of the segment (70). The lugs (88, 90) are positioned so that the movement of the gate element (68) relative to the segment (70) from the fully collapsed position results in the spring (92) exerting at least seventy percent of its total force on the lug (88 or 90) that is leading with respect to the direction of relative movement of the segment (70).

Abstract: A valve seat structure for an expanding type gate valve (20). A valve seat (64) is received in each annular seat recess (62) formed around the upstream and downstream flow passages (24, 26) and opening to the valve chamber (22) wherein a gate assembly (32) is movable between open and closed positions. An annular face seal (82) is mounted within an annular groove (70) in the front seat face (66) of each valve seat (64). A substantial portion of the bottom (76) of the annular groove (70) comprises a frusto-conical bottom portion (80) which forms a wedging surface with a cone angle in the range of approximately 30.degree. to 60.degree. and disposed substantially coaxial with the groove sides and the flow passages. The rear seal face (86) of the face seal (82) has a frusto-conical rear portion (94) that conforms to the frusto-conical bottom portion (80). The annular groove (70) is wider than the thickness of the face seal (82 ) so that the face seal loosely fits within the annular groove.

Abstract: A gate valve having a gate assembly of the expanding type employing a gate element (34) and segment (36) with adjacent wedge surfaces to expand the gate mechanism in both open and closed positons. Opposed floating seat skirts (68) having integral seat assemblies (52, 54) are positioned on opposite sides of the expanding gate valve and have facing slots (76) therein to receive spacer plates (82) therein which maintain a predetermined spacing between the skirts to minimize any binding of the skirts against the gate assembly and to provide a predetermined minimum clearance between the skirts at all times.

Abstract: A packing assembly for a valve shaft or stem (8) consisting of inner and outer telescoping expander sleeves or rings (44, 46) slidably received intermediately in a stuffing box (32) between two groups of elastomeric sealing rings (F, G). Semi-fluid plastic sealing material is injected (60) between the expander rings to move them apart and thereby axially compress and radially expand the seal rings into sealing engagement with the stem or shaft and box wall. Portions of the plastic material pass through radial holes in the inner expander ring to form secondary seals within and about these rings.