Abstract: A method of forming a stem seal and controlling the sealant film thickness in a lubricated plug valve in which a deformable ring is inverted in an annular space between the stem, the valve cover and the top of the plug and the ring is deformed into sealing engagement with the plug, the stem and cover by applying pressure to the sealant system of the valve during assembly.

Abstract: An improved plug valve is of the type that includes a valve body having a bore extending therethrough and a pair of passages intersecting the bore and being substantially normal to the axis of the bore. A valve plug is disposed within the bore for selective rotation between an opened and a closed position to respectively align and misalign a port through the plug with the passages. A first circumferential sealing member between the plug and the bore above the port and the passages and a second circumferential sealing member between the plug and the bore below the port prevents fluid from escaping from an interior of the plug valve and balances fluid pressure acting on the plug. A circumferential sealing device around the top of the plug prevents ingress of foreign matter into the region of the bore above the first sealing member.

Abstract: A valve actuator includes a hydraulic cylinder with a pair of pistons separately, slidably mounted therein for movement between a first end and a second end of the cylinder. An actuator rod is joined to a first of the pistons to extend through an opening in the first end of the cylinder to terminate exterior thereto and be capable of being joined to a valve stem. A high pressure gas accumulator is mounted on the cylinder to locate the second end thereof within the accumulator. The second end of the cylinder has an end closure with access therethrough to allow communication between the interior of the accumulator and a first side of the second piston of the pair. Normally, hydraulic oil is supplied to the cylinder to act on the first piston thereby causing both pistons to move axially against the high pressure gas of the accumulator which, in turn, axially moves the pistons when the hydraulic fluid is discharged.

Abstract: An improved plug valve is of the type that includes a valve body having a bore extending therethrough and a pair of passages intersecting the bore and being substantially normal to the axis of the bore. A valve plug is disposed within the bore for selective rotation between an opened and a closed position to respectively align and misalign a port through the plug with the passages. A first circumferential sealing member between the plug and the bore above the port and the passages and a second circumferential sealing member between the plug and the bore below the port prevents fluid from escaping from an interior of the plug valve and balances fluid pressure acting on the plug. The improvements include providing opposed circumferential semi-circular grooves respectively on the bore and the plug to define a circumferential channel therebetween. The body includes a circular hole extending therethrough which is tangentially aligned with the channel.

Abstract: A method of limiting backseat loading on a valve stem moved between a lower closed position and an upper open position engaging the backseat by an actuator having an upper stop position wherein the method includes the steps of setting a variable force transmitting coupling to a predetermined loading between a bearing surface and a gauging surface thereon, connecting the coupling to the valve stem in the lower closed position, lowering the actuator from the upper stop position, connecting the coupling to the actuator, raising the actuator to the upper stop with the backseat being below the upper open position, and increasingly connecting the coupling to the valve stem and the actuator until the backseat is engaged and the predetermined loading exceeded as ascertained by separation of the gauging surface from the bearing surface.

Abstract: A coupling for drivingly connecting two members operatively coupled at a lost motion connection including first and second sets of Belleville springs separated by a double tapered annular spacer wherein the apex rims of the outer springs engage the members and the base rim of the inner springs engage the outer periphery of the opposed surface of the spacer, the base surfaces of the inner springs fully engaging the spacer at a predetermined tensile load to prevent overdeflection of the springs and to directly couple the members together.

Abstract: An all-plastic valve having a unitary body has a cap assembly for excluding external contaminants from the interior of the valve while allowing venting of excess pressure from the interior.

Abstract: A valve positioning handle is for a plastic valve which is capable of being utilized in gas distribution pipes and includes a body and a fluid isolation member rotatably disposed therein. If the valve becomes jammed, it and/or the pipe are capable of being destroyed by the application of excessive forces to the isolating member and the body during rotation. The valve positioning handle includes an extended fitting centrally aligned with the isolation member and has a number of working surfaces thereon for the receipt of different torque applying tools. A connecting section between the extended fitting and the isolation member is designed to fail prior to the generation of any excessive forces which might destroy the valve or pipe by a tool being utilized to rotate the fitting.

Abstract: A valve positioning handle for a plastic valve includes a fluid isolation member rotatably disposed in a valve body and rotatable therewithin by means of different torque applying tools having legs selectively engageable with discretely oriented working surfaces.

Abstract: An improved cylindrical plug valve is of the type which includes a body having a cylindrical bore and a pair of axially aligned passages intersecting the bore and normal thereto. A cylindrical valve plug is rotatably disposed within the bore for movement between an opened and closed position for respectively aligning and misaligning a diametral port therethrough with the passages. Sealing rings around the plug above and below the port and passages prevent fluid from escaping from the interior of the plug valve. The improvement includes a pair of cup shaped recesses at opposite sides of the plug which are aligned with the passages when the valve is closed. Each recess is larger than the passage and has a substantially flat bottom and a peripheral side wall.