A live load stinger apparatus and method which operate to automatically deliver an additional amount of an injectable packing material or grease into the stem packing chamber of a valve assembly in order to prevent stem leaks from occurring.

A valve configured to control a flow of a process fluid includes a pair of packing seals separated by a seal gap space along a linear valve stem of the valve, and a pressurization port that can be used to apply a pressurizing fluid, such as nitrogen gas, to the seal gap at a gap pressure that is higher than the process fluid pressure, thereby ensuring that any leakage past the packing seals will be of pressurizing fluid into the process fluid and/or into the environment, and that no process fluid will escape into the environment. The pressure or flow rate of the pressurizing fluid can be monitored to detect and quantify any pressurization fluid leakage past either of the packing seals, so that a maintenance action can be applied to the valve, such as re-tightening or replacing at least one of the packing seals, or replacing the valve.

An electric valve and an assembly method therefor. The provision of multilayered sealing of a first sealing element, a second sealing element, and a sealing medium located between the first sealing element and the second sealing element along the axial direction of a valve stem is conducive to restricting outward leakage of a fluid along the axial direction of the valve stem.

In a valve (10) having a pneumatic or hydraulic drive unit (20), the drive unit (20) includes a cylinder (22), a piston (24), a spindle unit (26) mounted for axial movement in the cylinder (22), and a housing cover (28), the piston (24) dividing the interior of the cylinder (22) into a cover-side space (42) and a valve seat-side space (40), and a duct (66) within the spindle unit (26) leading to the valve seat-side space (40). Formed in the housing cover (28) are a fluid intake (44) and a fluid exit (46) as well as a pressure fluid duct (48) in fluid communication with the fluid intake (44) and an outlet duct (50) in fluid communication with the fluid exit (46). The pressure fluid duct (48) branches into two partial ducts (54, 56), a first partial duct (54) extending through the spindle unit (26) into the valve seat-side space (40) and opening out there, and a second partial duct (56) opening out into the cover-side space (42), and a closure body (68) being provided which seals either the first partial duct (54) or the second partial duct (56) in a fluid-tight manner. Furthermore, a modular system (70) and a method for manufacturing valves (10) are indicated.

A two-piece valve shell (body and bolted-on top bonnet) structure reduces possible leakage paths while also providing a top-side ball/stem installation/removal path (when the bonnet piece is not present) to facilitate initial valve assembly as well as subsequent inspection/removal of the ball/stem and other valve internals for conducting valve maintenance without requiring the valve body to be removed from its process connections. Internal wetted valve surfaces are coated with tantalum to provide a tantalum ball valve suitable for use as a sulfuric acid feed valve in severe high-temperature high-pressure industrial processes such as HPAL processes. Sealing cavities created by spaced-apart body-to-bonnet and/or stem-to-bonnet sealing structures can be inertly pressurized to hermetically isolate the sealing structures from ingress/leakage of corrosive process materials.

A piston and cylinder assembly structured to reduce breakaway friction (stiction) upon movement of the piston within the cylinder. The assembly includes a cylinder housing, a piston having a piston crown with a top face and one or more peripheral grooves, and an O-ring positioned on the piston in each of the one or more peripheral grooves. The piston crown incorporates one or more passageways extending from a space above the piston to a location within the peripheral groove inside of (behind) the O-ring. An increase in a volume of fluid in the chamber above the piston directs fluid through the passageways into the peripheral groove, thereby pressing the O-ring against the cylinder wall. A double acting piston embodiment uses at least two O-rings positioned within at least two grooves, each with associated fluid flow passageways into the grooves behind the O-rings.

A leakage blocking device of a valve is disclosed. When a fluid flowing in a flow path 11 leaks through a gap between the outer circumferential surface of a valve stem bottom (21) and a bottom guide hole (31), a plug 53 of a piston 50 is pushed into a sealing oil chamber 45 by a pressure P1 of the leaked fluid acting on a bottom pressure acting surface S1 of the piston and pressurizes a sealing oil L in the sealing oil chamber 45 to a pressure P2 higher than the pressure P1 of the leaked fluid, thereby blocking leakage of fluid of the valve.

A seal assembly for a valve stem comprises an external seal placed on a valve stem facing an external environment; an internal seal placed on the valve stem facing a process environment; the external and internal seals define a chamber for the containment of barrier fluid; the chamber has an inlet configured to be placed into fluid communication with a source of barrier fluid; a detector of the amount of barrier fluid; a pressurizer device for providing the chamber with a positive pressure with respect to the process environment; the pressurizer device is configured to be installed coaxially with the valve stem.

A valve for controlling a flow of process fluid, the valve including a housing; a shaft having a closing member, the shaft being received in the housing, and arranged to move axially relative to the housing; an outer seal arrangement for preventing process fluid from entering the housing, the outer seal arrangement including at least one dynamic radial outer seal enclosing the shaft; an inner seal arrangement, axially spaced from the outer seal arrangement along the shaft, the inner seal arrangement including at least one dynamic radial inner seal enclosing the shaft; and a buffer liquid chamber containing buffer liquid, the buffer liquid chamber being configured to provide buffer liquid to the shaft, and being arranged between, and sealingly closed by, the outer seal arrangement and the inner seal arrangement.

The present disclosure discloses an oil-retaining mechanism, a valve structure, and a water outflow device. The oil-retaining mechanism comprises a valve body, a valve shaft, and a sealing member. The valve body comprises a motion cavity. The valve shaft is disposed in the motion cavity and configured to move axially. The sealing member is disposed between a cavity wall of the motion cavity and the valve shaft. At least one of the cavity wall of the motion cavity, the sealing member, or a connection portion of the motion cavity, the sealing member, and the valve shaft extends inward to define an oil storage groove. The oil storage groove comprises an opening. An inner side of the opening stores lubricating oil. The opening cooperates with and contacts the outer circumferential surface of the valve shaft. When the valve shaft moves in the motion cavity, the lubricating oil lubricates the valve shaft.