A gate valve and a seat for a gate valve having a valve body, which may be used for hydrocarbon well fracturing operations with a fracturing fluid, or “frac fluid”, includes a seat pocket for receipt of the seat, which seat may include a tubular member having a seat end face, the seat end face includes two annular seals disposed in seat grooves, at least one of which is a half-dovetail groove.

A system including a valve. The valve includes a valve body having an interior volume and a bore along a first axis. A stem extends along a second axis and a flow control element couples to the stem. The stem selectively moves the flow control element through the interior volume between a closed position and an open position relative to the bore. A valve insert system retains a pressurized lubricant in the interior volume.

An embodiment includes a gate valve comprising: a valve body including a cavity coupled to a channel having proximal and distal portions; a gate to seal and unseal the channel; proximal and distal seats adjacent the gate; wherein (a) the proximal seat traverses towards the gate and stops at a first position when the gate is closing and the proximal channel portion is more highly pressurized than the cavity, and (b) the distal seat slides away from the gate and stops at a second position when the gate is closing and the cavity is more heavily pressurized than the distal channel portion. Other embodiments are described herein.

A sealing apparatus includes a moveable seal holder with a cavity and includes a seal assembly disposed at least partially in the cavity. The seal assembly includes a resilient seal member including a fluid-facing end with a fluid-facing end surface, and the seal assembly includes an actuator plate configured to reciprocate between a first and a second position relative to the protective plate. The first actuator plate includes a fluid-facing end surface and a first camming surface. The seal assembly further includes a first protective plate disposed between the seal member and the first actuator plate. The actuator plate is configured to compress the seal member and to move the fluid-facing end surface of the seal member outward from a resting position when the actuator plate is in the second position.

A gate valve system includes a body including an upstream end, a downstream end, and a flow path extending through the upstream end and the downstream end. The gate valve system includes a gate assembly extending within the body, the gate assembly including a gate a stem secured to the gate and configured to place the expandable gate in a first position in which a flow of fluid is permitted between the upstream end and the downstream end and a second position in which the flow of fluid is prevented. The gate valve system also includes a lubrication port in an exterior of the body, the lubrication port being in fluid communication with an interior of the body and including a lubrication guiding insert configured to guide a supply of lubricating fluid to a location inside the body and between the upstream end and the downstream end.

An embodiment includes a gate valve comprising: a valve body including a cavity coupled to a channel having proximal and distal portions; a gate to seal and unseal the channel; proximal and distal seats adjacent the gate; wherein (a) the proximal seat traverses towards the gate and stops at a first position when the gate is closing and the proximal channel portion is more highly pressurized than the cavity, and (b) the distal seat slides away from the gate and stops at a second position when the gate is closing and the cavity is more heavily pressurized than the distal channel portion. Other embodiments are described herein.

An isolation knife gate valve has a valve body including pipe couplings. Removable face sealing elements are attached on either side of the valve body interior to the pipe couplings. A perimeter seal may also be mounted within the valve body. The face sealing elements may include flexible seal elements extending around the opening. The flexible seal elements may cooperate with the perimeter seal, having portions contacting side surfaces of the perimeter seal and other portions contacting faces of the valve gate.

A singular piston included behind a valve seat within a gate valve assembly can be energized by external pressure through a hydraulic port within the valve body. When the back side of the singular piston is energized, the singular piston applies force in one direction against the adjacent valve seat, valve gate, opposing valve seat and valve seat pocket in both the valve open position and the valve closed position to block any unwanted matter from moving into the valve backside cavity. A singular piston has a pressure sealing surface and a piston pocket with an adjacent pressure sealing surface that allows the valve to seal in the closed position with the contained fluid bore pressure against the opposing valve body flow path side to the piston without the piston being energized.

A gate valve for controlling a flow of a fluid. The gate valve includes a valve body with a first seat pocket and a flow bore, a gate which is movable so as to intersect the flow bore, a seat with a gate end and a body end, a plate with an opening which is positionable on the seat at the gate end, and a plate retainer which is positionable between the seat and the plate so as to prevent an axial movement between the seat and the plate with respect to an axis of the flow bore. The flow bore extends through the valve body for the flow of the fluid. The gate end is arranged to face the gate, and the body end is positionable within the first seat pocket of the valve body.

A valve insert for a valve assembly, the valve insert positionable within a valve inlet end and/or a valve outlet end and including a fluid passageway to permit fluid flow through the valve assembly. The valve insert is formed having an outer surface for supporting the valve insert within the bore and an inner surface defining a fluid passageway, the inner and outer surfaces extending longitudinally between a proximal face configured to engage a valve seat, and an opposed outer face. The valve insert further includes a recessed portion formed on the outer surface, the recessed portion being configured to receive a seal to sealingly engage the bore.