A pressure relief valve is disclosed with a first stage valve that is in series with a second stage valve, with an enclosed cavity between the first stage valve and the second stage valve. The first stage valve relieves pressure from an enclosure into the enclosed cavity between the stages, when the pressure is above a cracking pressure of the first stage valve. The second stage relieves pressure from the enclosed cavity when the pressure is above the cracking pressure of the second stage valve.

A pressure relief valve is disclosed with a first stage valve that is in series with a second stage valve, with an enclosed cavity between the first stage valve and the second stage valve. The first stage valve relieves pressure from an enclosure into the enclosed cavity between the stages, when the pressure is above a cracking pressure of the first stage valve. The second stage relieves pressure from the enclosed cavity when the pressure is above the cracking pressure of the second stage valve.

A fluid control valve having extremely high responsiveness not only when a pressure of a working fluid of a first flow path is high but also when the pressure of the working fluid of the first flow path is low includes: a valve seat; a valve body contacting and separating from the valve seat; a first biasing member biasing the valve body in a valve closing direction; and a second biasing member having a spring force lower than that of the first biasing member, wherein the valve body is axially divided into a base portion biased by the first biasing member and an opening and closing portion contacting and separating from the valve seat, and the second biasing member is disposed so that the base portion and the opening and closing portion are axially separable from each other.

A check valve bleed assembly eliminates the requirement for a person to enter the red zone when bleeding the grease out of a gate or other valve. A gas or other fluid is provided to the check valve bleed assembly. The gas or other fluid acts upon the surface driving a pin into the associated check valve with sufficient force to overcome the resistance of the object sitting on a seat and moves the object off of the seat. The force is maintained as long as is necessary. Usually, the check valve is held open until the gate transitions into the gate's associated gate recess thereby displacing the grease within the gate recess through the check valve, into the check valve bleed assembly, and finally to a waste collection tube. In some embodiments a gate valve greasing access port is included in the check valve bleed assembly such that grease may be injected into the check valve bleed assembly.

A check valve bleed assembly eliminates the requirement for a person to enter the red zone when bleeding the grease out of a gate or other valve. A gas or other fluid is provided to the check valve bleed assembly. The gas or other fluid acts upon the surface driving a pin into the associated check valve with sufficient force to overcome the resistance of the object sitting on a seat and moves the object off of the seat. The force is maintained as long as is necessary. Usually, the check valve is held open until the gate transitions into the gate's associated gate recess thereby displacing the grease within the gate recess through the check valve, into the check valve bleed assembly, and finally to a waste collection tube. In some embodiments a gate valve greasing access port is included in the check valve bleed assembly such that grease may be injected into the check valve bleed assembly.

A normally closed subplate mounted valve has a lower valve seat defining a function port, an upper seat, and a sleeve between the upper seat and the lower seat. The sleeve defines a first port. The poppet is movable within the sleeve to selectively seal against the lower seat in a piloted position or to seal against the upper seat in an offset position. The poppet blocks the first port when the poppet is positioned in an offset position. A piston shaft is affixed to the poppet for moving the poppet into the piloted or offset position. A spring biases the poppet in the offset position for preventing fluid flow into the first port. A pilot port supplies pressure for sliding the piston to compress the spring and to move the poppet away from the offset position to the piloted position so that fluid may flow into a supply port and out of the function port. A second port may be provided in the sleeve. The ports may be selectively configured for supply or vent. Components may be joined with retainer springs. The piston shaft and poppet connector may be a key and key slot engagement. The ports may be shaped for progressive exposure by movement of the poppet. The poppet may be designed to enable pressure assist through the first port when moving the poppet to the piloted position. The valve seats may be provided with angled sealing surfaces that are angularly offset from their mating counterparts.

A normally closed subplate mounted valve has a lower valve seat defining a function port, an upper seat, and a sleeve between the upper seat and the lower seat. The sleeve defines a first port. The poppet is movable within the sleeve to selectively seal against the lower seat in a piloted position or to seal against the upper seat in an offset position. The poppet blocks the first port when the poppet is positioned in an offset position. A piston shaft is affixed to the poppet for moving the poppet into the piloted or offset position. A spring biases the poppet in the offset position for preventing fluid flow into the first port. A pilot port supplies pressure for sliding the piston to compress the spring and to move the poppet away from the offset position to the piloted position so that fluid may flow into a supply port and out of the function port. A second port may be provided in the sleeve. The ports may be selectively configured for supply or vent. Components may be joined with retainer springs. The piston shaft and poppet connector may be a key and key slot engagement. The ports may be shaped for progressive exposure by movement of the poppet. The poppet may be designed to enable pressure assist through the first port when moving the poppet to the piloted position. The valve seats may be provided with angled sealing surfaces that are angularly offset from their mating counterparts.

A pressure relief valve assembly is disclosed. The pressure relief valve assembly comprises an inlet manifold, a first pressure relief valve, a second pressure relief valve, and an outlet manifold. The first pressure relief valve is connected to and in fluid communication with the inlet manifold. The second pressure relief valve is connected to and in fluid communication with the inlet manifold and parallel to the first pressure relief valve. The outlet manifold is connected to and in fluid communication with the first pressure relief valve and the second pressure relief valve.

A pressure relief valve assembly is disclosed. The pressure relief valve assembly comprises an inlet manifold, a first pressure relief valve, a second pressure relief valve, and an outlet manifold. The first pressure relief valve is connected to and in fluid communication with the inlet manifold. The second pressure relief valve is connected to and in fluid communication with the inlet manifold and parallel to the first pressure relief valve. The outlet manifold is connected to and in fluid communication with the first pressure relief valve and the second pressure relief valve.

A normally closed subplate mounted valve has a lower valve seat defining a function port, an upper seat, and a sleeve between the upper seat and the lower seat. The sleeve defines a first port. The poppet is movable within the sleeve to selectively seal against the lower seat in a piloted position or to seal against the upper seat in an offset position. The poppet blocks the first port when the poppet is positioned in an offset position. A piston shaft is affixed to the poppet for moving the poppet into the piloted or offset position. A spring biases the poppet in the offset position for preventing fluid flow into the first port. A pilot port supplies pressure for sliding the piston to compress the spring and to move the poppet away from the offset position to the piloted position so that fluid may flow into a supply port and out of the function port. A second port may be provided in the sleeve. The ports may be selectively configured for supply or vent. Components may be joined with retainer springs. The piston shaft and poppet connector may be a key and key slot engagement. The ports may be shaped for progressive exposure by movement of the poppet. The poppet may be designed to enable pressure assist through the first port when moving the poppet to the piloted position. The valve seats may be provided with angled sealing surfaces that are angularly offset from their mating counterparts.