An eccentric butterfly valve that maintains high sealability when closed even when a high-pressure fluid is oriented in either direction of a forward flow or backflow. The valve includes a disk (23) axially supported at an eccentric position via a stem (22) inside a body (21). The disk is provided to a seat ring (24) fixed with a seat retainer (25) so as to be hermetically sealable. A flexible part is formed on an inner diameter side of the seat ring, and a spring member is mounted between the flexible part and the seat retainer. In the spring member, a load increases substantially in proportion to the magnitude of tilt of the flexible part when the disk is displaced to a seat retainer side. When the flexible part is elastically deformed, the spring member is elastically deformed in a state where contact with the seat retainer is avoided.

A valve assembly for use in a fracturing pump including a valve member movable into and out of engagement with a valve seat body. The valve seat body includes an outer surface and an inner surface, the inner surface forming a fluid bore extending between a first end and a second end of the valve seat body. The body further includes a seating surface extending radially from the inner surface and facing the valve member, the seating surface having a recessed area. An insert is disposed in the recessed area forming at least a portion of the inner surface and at least portion of the seating surface. The valve seat body first end has a diameter different from a diameter valve seat body second. The difference between diameters allows the valve seat body outer surface to be supported by the fluid passageway.

Provided are sealing member for electronic valve, electronic valve with sealing member, electronic valve with static sealing structure, and electronic valve with double sealing structure. The sealing member has inlet end connected to valve core and outlet end connected to connecting pipe; the electronic valve includes valve body, valve cover, flow rate control device, and the connecting pipe; the flow rate control device includes the valve core; the valve body is provided therein with valve core accommodating chamber and connecting pipe connection port; the valve core is disposed in the valve core accommodating chamber; the connecting pipe is welded to end of the connecting pipe connection port on the valve body. The electronic valve further includes the above sealing member, and the sealing member is located between the connecting pipe and the connecting pipe connection port. Meanwhile, the electronic valve includes static sealing structure and/or double sealing structure.

A plug for a fluid valve has a stem extending along an axis between a first end and a second end, a tip secured to the first end of the stem, a plug body mounted to the stem toward the second end relative to the tip, and a valve seat between the tip and the plug body. The valve seat has a sealing surface that extends past an outer perimeter of the tip and is sized to engage a valve ring of the fluid valve, the valve seat defining an annular space that permits radial movement of the valve ring relative to the axis of the stem to align with the valve ring as pressure is applied to the valve seat.

A valve closing member for cooperating with a valve seat, comprising: a body a front circular face forming a central protrusion along a longitudinal axis of the body; a seal forming a ring fitted on the front circular face and around the central protrusion; and a retainer forming a ring surrounding the seal and attached to the body for retaining the seal on the body; wherein the seal shows a radially inner surface contacting a radially outer surface of the central protrusion, the radially inner surface and radially outer surface being both cylindrical, the radially outer surface showing at least one circular groove into which the seal is radially pressed by the retainer.

A valve closing member for cooperating with a valve seat, comprising: a body a front circular face forming a central protrusion along a longitudinal axis of the body; a seal forming a ring fitted on the front circular face and around the central protrusion; and a retainer forming a ring surrounding the seal and attached to the body for retaining the seal on the body; wherein the seal shows a radially inner surface contacting a radially outer surface of the central protrusion, the radially inner surface and radially outer surface being both cylindrical, the radially outer surface showing at least one circular groove into which the seal is radially pressed by the retainer.

A valve includes at least one valve stem seal, such as a packing seal, that is included in a removable seal cartridge. The valve stem is connected to the actuator via a linkage, which can be removed to provide a linkage gap between the actuator and the valve stem. The seal cartridge can then be slid along the valve stem into the linkage gap and laterally removed from the valve, whereupon the seals within the seal cartridge can be refurbished. The valve can be a rotary or linear valve. In embodiments, the linkage gap can be increased by linear displacement of the actuator away from the valve stem. The seal cartridge can be re-installed in the valve after refurbishment, or a substantially identical replacement seal cartridge can be provided, and can be installed in the valve in replacement of the removed seal cartridge, thereby minimizing downtime of the valve.

A check valve includes a housing defining an inlet, an outlet, a passage between the inlet and outlet, and a sealing surface along the passage. A piston member is disposed about a longitudinal axis and has a sealing face disposed perpendicular to the longitudinal axis and a circular groove defined therein extending inward from the sealing face. An O-ring is disposed in the groove. A biasing member exerts a biasing force on the piston and thus forces the O-ring into sealing engagement with the sealing surface of the housing. The piston member is moveable from a first position in which the O-ring is sealingly engaged with the sealing surface of the housing and thus the outlet is sealed from the inlet, and a second position in which the O-ring is spaced from the sealing surface of the housing and thus the outlet is not sealed from the inlet.

A seat carrier subassembly for a valve includes an annular seat carrier body including an annular projection extending radially into a central passage, and an annular plastic seal ring over-molded onto the annular projection, with the annular plastic seal ring defining a seat seal.

A valve disc gasket for use in a fluid flow control valve includes a frustoconical, ring-shaped body part having a plurality of circumferentially distributed asymmetrical, through-going openings and/or slits and/or asymmetrical protrusions, wherein an internal surface of the respective asymmetrical through-going opening and/or slit forms a vane surface and/or wherein an external surface of the respective asymmetrical protrusion forms a vane surface, wherein the asymmetrical through-going openings and/or slits and/or protrusions are asymmetrical at least in the sense that respective through-going opening or slit and/or protrusion is asymmetric relative to any radial plane intersecting the respective through-going opening or slit and/or the respective protrusion. Also disclosed is a fluid flow control valve and a method for cleaning a fluid flow control valve.