A pressure relief valve flap includes an attachment portion, a main portion, and a hinge portion. The attachment portion is configured to be attached to the housing. The main portion has a lip and at least one damping feature. The lip extends around at least a portion of a periphery of the main portion. The hinge portion is disposed between and connects the main portion and the attachment portion. When the attachment portion is attached to the housing, the main portion is configured to move between a closed position and an opened position. When the main portion moves from the opened position to the closed position, the at least one damping feature is configured to engage the housing prior to the lip of the main portion and thereby dampen noise created when the lip of the main portion engages the housing.

A device for controlling the flow of fluid through a conduit from an upstream side of the device to a downstream side of the device. The device includes a valve seat mounted on a casing that defines a valve aperture, a mounting member arranged on the downstream side of the valve aperture; a valve member mounted on the mounting member. The valve member is arranged to selectively open and close the valve aperture thereby controlling the flow of the fluid through the valve aperture. A seal retaining member is arranged adjacent the valve seat and, with the valve seat, defines a seal retaining groove. A compliant seal within the seal retaining groove seals the valve aperture when the valve member is moved to close the valve aperture.

An inlet port provides a fluid entrance to a body. A chamber has an inner surface. An outlet port is in fluid communication with the chamber and provides a fluid exit from the body. The piston is moveable within the chamber between a first set position, in which the inlet port is not in fluid communication with the outlet port, and a second open position, in which the inlet port is in fluid communication with the outlet port through the chamber. A seal guard is slidably disposed within the chamber. The seal guard is moveable between a first seal-guard position and a second seal-guard position in which the seal guard shields the seal. The seal guard is in the first seal-guard position when the piston is in its first set position and in the second seal-guard position when the piston is in its second open position.

A reciprocating gas compressor valve having a plurality of clusters of kidney shaped holes positioned along a common circular or annular locus in the main body and a sealing element with a top portion, a bottom portion and a tubular section. The tubular section is integrally connected to the top portion and bottom portion. In an open position, a flow pathway is provided through the clusters of kidney shaped holes and the tubular section and the bottom profile abuts a stop surface of the valve. In a closed position, the top profile abuts the seat for sealing gas flow within the valve.

A spring-operated relief valve can include an adjustable main spring to bias the valve closed and a load cell that is configured to measure a force exerted by the main spring. Measurements from the load cell can be used to determine a set or crack pressure in the spring-operated relief valve, and to monitor operation of the spring-operated relief valve.

An injection valve including a housing, a fluid channel in the housing, and a check valve disposed in the housing and responsive to fluid pressure in the channel to move the check valve in a direction opposite the direction of fluid flow through the channel. A method for injecting fluid into a volume including pressurizing a fluid to be injected, conveying the pressurized fluid to a space about a check valve between a check valve nose and a stem seal; and moving the check valve in a direction opposite a direction of injection fluid flow. A borehole system including a borehole in a subsurface formation, a string disposed within the borehole, and an injection valve disposed within or as a part of the string.

A reciprocating gas compressor valve having a plurality of clusters of kidney shaped holes positioned along a common circular or annular locus in the main body and a sealing element with a top portion, a bottom portion and a tubular section. The tubular section is integrally connected to the top portion and bottom portion. In an open position, a flow pathway is provided through the clusters of kidney shaped holes and the tubular section and the bottom profile abuts a stop surface of the valve. In a closed position, the top profile abuts the seat for sealing gas flow within the valve.

A spring-operated relief valve can include an adjustable main spring to bias the valve closed and a load cell that is configured to measure a force exerted by the main spring. Measurements from the load cell can be used to determine a set or crack pressure in the spring-operated relief valve, and to monitor operation of the spring-operated relief valve.

A reciprocating gas compressor valve having a plurality of clusters of kidney shaped holes positioned along a common circular or annular locus in the main body and a sealing element with a top portion, a bottom portion and a tubular section. The tubular section is integrally connected to the top portion and bottom portion. In an open position, a flow pathway is provided through the clusters of kidney shaped holes and the tubular section and the bottom profile abuts a stop surface of the valve. In a closed position, the top profile abuts the seat for sealing gas flow within the valve.

A pressure relief valve having two rigid sealing surfaces lapped to a smoothness Ra of 8 micro-inches or less, and flatness within 80 micro-inches, forms a reliable seal by direct contact therebetween without an elastomer. The sealing surfaces and surrounding structures can be made of one or more metals, such as alloys of stainless steel, and can be CTE-matched, so that the valve is not impeded by environmental temperature changes. In a disclosed embodiment, a poppet is axially pressed against a seal plate by a spring. The poppet can be axially stabilized by sliding within a surrounding cylinder or spacer, and can contact the surrounding surface with a plurality of arms that reduce friction and enable gas flow therebetween. The poppet can be made from anti-galling Nitronic 60 alloy, and the surrounding structures can be stainless steel. Embodiments are suitable for low-pressure gas applications in extreme environments.