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.

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 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 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 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 valve for use in oil and gas production or similar applications includes a plug or other flow barrier disposed in a cavity of a hollow valve body with a metal-to-metal sealing surface that is not reliant on any rubberized or elastomeric material to effect a seal.

Improved apparatuses, systems, and methods for sealing a frac valve using pressurized fluid to drive one or more seal assemblies into sealing contact with a valve gate without substantial relative movement of the seal assembly components. In some embodiments, the improved apparatuses, systems, and methods provide a sealant to the face of the valve gate to ensure a fluid tight seal, a plurality of biased springs to ensure the seal assemblies are positioned properly to create a fluid tight seal, a shield to prevent fluids, particulates, and/or other materials from interfering with the operation of or damaging the seal assemblies, and/or a recess for receiving fluids, particulates, and/or other materials that would otherwise interfere with a fluid-tight seal or cause damage to the seal assemblies or valve gate.

A valve seal assembly can be energized by external pressure, such as by hydraulic pressure introduced via injection ports, so as to press the seal assembly against a gate with enough force to block paths where sand and chemicals would otherwise enter the valve body cavity or void. The external pressure makes the parts of the seal assembly move like a piston, forcing the seat of the seal assembly to press against the gate, eliminating the machined tolerances or gaps required for the gate to be opened or closed. A separate valve seal assembly can be provided for each face of the gate, and both assemblies can be activated when the gate is in an open position (fluid is flowing through the valve), and an upstream valve seal assembly can be activated alone when the gate is in a closed position.

A nozzle is configured for interaction with a sewer inlet fitting. The sewer inlet fitting is configured for connection to a sewer inlet of a sewer system or sewage receptacle. The sewer inlet fitting includes a cover operable between open and closed conditions by action of the nozzle being inserted thereinto and withdrawn therefrom.