Abstract: A top-entry ball valve 10 comprising a valve body 12 having a chamber 13, flow passages 14, 15, a ball 20 rotatably mounted in the chamber for movement between open and closed positions relative to the passages, and a pair of seat assemblies 50 at opposed sides of the ball which may be loaded into engagement with the ball or disengaged therefrom. Each seat assembly 50 comprises a seat ring 51 having a rear portion 51a, a larger diameter portion 51b which forms a shoulder 51c, and a face seal 59. Three pins 65 in the seat ring 51 in equiangular spaced relation project from the shoulder 51c. A spacer ring 53 sleeved about the rear 51a of the seat ring 51 is provided with recesses 68 adapted to receive the pins 65. The spacer 53 is mounted for movement between a first position where it is engaged by the tips of pins 65 and a second position wherein the pins 65 are in the recesses 68.

Abstract: A piston type pneumatic powered actuator (9) for operating a valve (10) of the expanding gate type wherein velocity of the piston-stem-gate drive train is maintained substantially constant in the latter stage of the actuator stroke. The actuator (9) includes an assembly of dual pistons (61,75) which are adapted to be driven by fluid pressure in one direction to operate the valve but are returned by spring means (66,67) when the fluid pressure is removed. A drive piston (61) directly connected to the actuator stem (23) is nested within a primary piston (75) which is not connected to the actuator stem (23) but moves the drive piston (61) when actuating pneumatic fluid is applied to the actuator (9). A stop (85) affixed to the primary piston (75) is adapted to cooperatively engage the actuator housing (40) to terminate the stroke of the primary piston (75) prior to termination of the stroke of the drive piston (61).

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 dual stage hydraulic actuator (9) for actuation of an expanding gate valve (10). The actuator is mountable to the valve housing and comprises a housing 40 which defines a piston chamber 41 and a primary piston (61) slidably received therein. An actuator stem (23) connects the piston (61) to the valve gate assembly (20). A secondary piston (77), of smaller piston area than the primary piston (61), is slidably received in a piston receiving bore (75) which is formed in the fluid receiving face of the primary piston. A piston rod (80) connects coaxially with the piston (77) and extends through the end (52) of the actuator housing. The actuator is responsive to hydraulic fluid pressure which when applied through an inlet (71) of the actuator housing to one side of the pistons (61, 77) drives the actuator stem and gate assembly to an operational open or closed position of the valve.

Abstract: A crossover seal assembly (44) for sealing the annulus between a well casing (16) and tubing head (22). The assembly includes spaced pairs of upper and lower metal seal rings (60 and 72, 108 and 120) having matching frusto-conical wedging surfaces (70 and 74, 118 and 122) which interact when an axial compressive force is applied to thereby effect a controlled radial expansion of the seal rings to sealingly engage the inner and outer cylindrical surfaces (48, 47) of the tubing head (22) and well casing (16). The axial compressive force is mechanically applied by a plurality of holddown lock screws (90) which interact through tapered conical tips (94) to energize the crossover seal assembly (44).

Abstract: An expanding gate valve (10) provided with a piston type pneumatic powered actuator (40) for opening and closing the valve wherein the actuator piston (54) is adapted to be driven by fluid pressure in one direction to operate the valve but is returned by spring means (63, 64) when the pressure is removed. The actuator includes a hydraulic choke means (71) comprising a hydraulic piston (80) and cylinder (72) wherein the hydraulic piston is fixed to the actuator stem (23) and is provided with an orifice (89) which imposes a constant velocity control on the actuator stroke by producing a throttling effect on the hydraulic fluid moving from one side of the hydraulic piston to the other. The hydraulic cylinder (72) is filled with a fluid which maintains substantially uniform viscosity in the range of minus 40.degree. Centigrade to 204.degree. Centigrade whereby the valve is adapted for consistent operation during rapid cycling conditions.

Abstract: A block valve (10) for selectively establishing and selectively blocking communication between a pressurized fluid supply (30), a fluid actuated device (DHSV) and a reservoir (35). The valve comprises a valve body (41, 42) with an inlet (81), an outlet (82) and a bleed port (83) and first and second piston-type plunger elements (61, 71) slidably mounted in piston chambers (51, 52) formed in the bore (43, 45) of the valve body. The second plunger element (71) is slidably mounted on the first plunger element (61) in sleeved relation therewith. Both plunger elements (61, 71) are continuously urged by springs (66, 75), respectively, to a first operating position wherein communication between the ports (81, 82, 83) is blocked by seal means (94, 95, 96) and blocking means (64) mounted on the plunger elements.

Abstract: A pressure energized mechanically preloaded packing assembly (48, 68) of a high pressure gate valve (10). The packing assemblies are positioned in an annular space about the valve stems (36, 64) for sealing between the valve stems and bonnet (38) or valve body (12). The packing assemblies include an energizer ring (78) which is positioned within the annular space having an outwardly facing precision cut frusto-conical end surface (82) relative to the flow passage (16, 18) of the valve. A plurality of Belleville springs or spring washers (98) with a generally frusto-conical shape are positioned adjacent and in concave relation to the outer end (82) of the energizer ring. The cone angle of the spring washers are smaller than the cone angle of the energizer ring. The packing assembly further includes at least one packing ring set positioned outside the spring washers (106, 108) which includes a stack of plastic packing elements (110) which are sandwiched between a pair of retainer rings (112, 114).

Abstract: A valve seat structure adapted to be positioned within each annular seat pocket (37, 36) which is formed about the flow passage (12, 13) adjacent the valve chamber on both the upstream and downstream sides of the gate element of a gate valve. The valve seat structure comprises a metallic seat ring (40) which fits snugly within the seat pocket (36, 37) but has an axial dimension which exceeds the depth of the pocket. The seat ring is formed with an annular notch (49, 50) in the outer corner of the ring at its rear face (48) for accommodating a resilient O-ring (66) therein. In its front face (47) the seat ring is provided with an annular groove (51) coaxial with the ring axis and provided with serrated side walls (51a, 51b). A plurality of passages (55) are formed in the ring with equiangular spacing and extend from the face groove (51) to the corner notch (49, 50).

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: A high pressure in-line test valve (42) is positioned to block off a first fluid pressure source (10) acting on a control valve means (32 and 34) and to provide communication with an alternate test fluid pressure source (138) for testing the control valve means. The test valve (42) has a central bore (70) in which a depressible piston (78) is positioned for longitudinal movement between a seated extended position (FIG. 2) blocking the first fluid pressure source and simultaneously communicating test fluid to the control valve means, and an unseated retracted position (FIG. 3) re-establishing communication between the first fluid pressure source and the control valve means and simultaneously blocking the alternate fluid pressure source (138) with a dual sealing means.

Abstract: An improved plug mechanism for use with a wellhead tool for removing and replacing valves on an operating wellhead under pressure including an elongated housing with a fluid coupling on one end for connecting to the outlet end of a wellhead valve and a plug mechanism extending from the housing through the valve into the wellhead where it seals fluid flow to the valve. The plug mechanism includes an expandable sealing element and an improved latch mechanism including a plurality of ball bearings which are extendable and retractable from the plug mechanism to secure it solidly within the bore of the wellhead upstream of the valve to be removed. The housing is equipped with an operating mechanism to expand and retract the sealing member and to engage and release the ball bearings. The plug mechanism further includes an improved self-alignment feature to ease attachment of the operating mechanism to the plug mechanism once the plug mechanism has been secured within the bore of the wellhead.

Abstract: A sensor base structure (24) for supporting high and low pressure sensors (20,22) having autoclave type connectors (44) and communicating pressurized fluid from the main flowline (10) to the sensors. The sensor base structure comprises a cylindrical manifold (52) having a longitudinal passage (54) therein and including a plurality of lateral bores (58) extending therethrough intersecting the longitudinal passage. One end (60) of each lateral bore threadably receives the autoclave connectors of the respective pressure sensors. The opposite end (61) of the bore (58) threadably receives a plug (62) having an externally threaded portion (64) and a reciprocal autoclave connector (66) facing the pressure sensor to provide a high pressure metal-to-metal seal upon contact with the respective autoclave connectors.

Abstract: A pilot valve adapted for connection between a double acting fluid actuator (12) of the piston-type and a hydraulic fluid supply (21). The pilot valve comprises an elongate body (30) with an axial bore (32, 33) therethrough and a piston chamber (38) at one end of the valve body. A valve plunger (49) affixed to the piston (50) in the piston chamber (38) is mounted in the axial bore for movement between first and second operating positions in response to the selective application of pneumatic pressure to the piston (50). The valve (20) is provided with valve ports (56, 60) for accommodating connections with a hydraulic fluid reservoir (21), and a piston-type actuator (12), respectively, whereby in the first operative position of the valve plunger (49), the valve (20) is conditioned for the transmission of hydraulic fluid to a first side of the actuator piston (17) and the removal to the sump (22) of hydraulic fluid from the other second side of the actuator piston (17) through valve ports (81, 75).

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 tool (10) for the installation and removal of back pressure valves or plugs in a wellhead under pressure conditions to permit repair and replacement of wellhead outlet valves. The tool (10) comprises an elongate cylindrical housing (31, 32, 33) in which a manipulator rod (30) is slidably mounted in axial alignment therewith. The tool (10) includes a piston (55) which is sleeved about the rod (30) and adapted to be selectively clamped thereto. The manipulator rod (30) is provided at one end with a back pressure valve of plug (84) attached thereto. The tool (10) includes a fluid controls system which is connectable to an external fluid pressure source (P) or the pressure of the well itself.

Abstract: A relay valve for controlling fluid flow to and from a valve actuator included in a safety system for a flowline such as a production line of an oil or gas well. The relay includes a slide valve (60) which is manually pushed inwardly to the open or set position and held therein by pilot fluid which is also applied to the valve actuator. A visual indicator mounted on a knob (102) of the slide valve is operated by fluid applied to a passage (96) formed in the slide valve. A vent port (82) prevents pilot pressure from moving the slide valve from the closed position to the open position. A modified relay valve (150) has separate inlet ports (198 and 200) for receiving pilot fluid and actuator fluid and a vent port (206) which is in direct fluid communication with the pilot port in the closed position of the slide valve.