Abstract: A pressure relief valve (PRV) assembly may include a housing having an opening therein, an interior cavity, a passageway extending between the opening and the interior cavity, and a flange extending within the passageway adjacent the opening. The PRV assembly may also include a first stage valve carried within the interior cavity, and a second stage valve fluidly coupled in series with the first stage valve. The second stage valve may include an enlarged head carried within the opening and a shaft extending from the enlarged head through the passageway to the interior cavity. The shaft may have a proximal end coupled to the enlarged head and an opposing enlarged distal end adjacent the interior cavity. A biasing member may be between the enlarged distal end and the flange. The biasing member may be configured to bias the first and second stage valves to a closed position.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A subsea vessel includes an outer layer of non-corrosive material and an inner layer of high-strength material that both corroborate in a subsea environment to withstand external pressure and prevent corrosion. The subsea vessel further includes a cavity surrounded by the inner layer and outer layer for providing storage in and protection from the subsea environment. The cavity is accessible via an opening that extends through the inner layer and the outer layer. The opening can be opened and closed with a cooperating cap that impermeably seals the cavity. The cap may include a number or connection mechanisms for being selectively secured to the opening. In addition, the cap may include a portion formed of a high-strength material and a portion formed of a non-corrosive material.

Abstract: An active user interface system includes a gimbal assembly that is configured as a dual-input/single-output differential mechanism. The differential mechanism implements a speed reduction from the inputs of the differential mechanism to the output of the differential mechanism. Speed reduction enables the maximum drive torque that is supplied to the user interface about one rotational axis to be greater than the maximum drive torque that is supplied to the user interface about another, perpendicular axis.

Abstract: Seals, ball valve assemblies, and methods of operating ball valves assemblies are provided. The seal includes an annular jacket, a restrictor, and a spring energizer. The annular jacket includes a first annular pocket and a second annular pocket. The restrictor is disposed in the first annular pocket and is capable of restricting shrinkage of the first annular pocket to a predetermined diameter range, if the seal is exposed to a temperature within a predetermined temperature range. The spring energizer is disposed in the second annular pocket and is configured to supply a force against the annular jacket to maintain the seal against a contact surface.

Abstract: A gas control valve is configured to controllably supply propellant gas to a thruster so that the thruster may produce thrust over a relatively wide range, and so that the thruster exhibits relatively fine minimum impulse bit (MIB) performance. The gas control valve includes a pilot stage having a pilot valve, and a main stage having a main valve. The gas control valve responds to control signals supplied to the pilot stage and is configured such that for commands of relatively short duration, only the pilot valve responds. Conversely, for commands of relatively longer duration, the pilot valve and main valve both respond.

Abstract: An electromechanical actuator is provided for converting rotary action into linear action, and includes an electric motor, a cable yoke, an output shaft, and a pair of cables. The electric motor is adapted to be selectively energized and is configured, upon being energized to generate a drive torque. The cable yoke is coupled to receive the drive torque and is configured, upon receipt thereof, to rotate about a rotational axis. The output shaft is coupled to receive a drive force and is configured, upon receipt thereof, to translate along a linear axis that is disposed at least substantially perpendicular to the rotational axis. Each cable is wound, in pretension, on a portion of the cable yoke and around a portion of the output shaft. The pair of cables is configured, upon rotation of the cable yoke, to supply the drive force to the output shaft.

Abstract: An active pilot inceptor system includes a pilot inceptor, a multi-phase motor, and a motor control. The pilot inceptor is configured to receive user input and is operable, in response to the user input, to move to a control position. The multi-phase motor is coupled to the pilot inceptor to selectively supply haptic feedback thereto. The motor control is operable to selectively energize the multi-phase motor in a manner that causes the multi-phase motor to generate torque and supply the haptic feedback to the inceptor, and to selectively energize the multi-phase motor in a manner that the multi-phase motor does not generate torque.

Abstract: A gas thruster is configured to supply thrust over a relatively wide range, from a relatively low value to a relatively high thrust value, and exhibits relatively fine minimum impulse bit (MIB) performance. The gas thruster includes a thrust nozzle, a main stage, a main valve element, and a pilot valve. The gas thruster responds to thruster control signals supplied to the pilot valve and is configured such that for commands of relatively short duration, only the pilot valve responds and relatively low thrust is produced. Conversely, for command or relatively longer duration, the pilot valve and main valve element both respond and relatively higher thrust is produced.

Abstract: Seals, ball valve assemblies, and methods of operating ball valves assemblies are provided. The seal includes an annular jacket, a restrictor, and a spring energizer. The annular jacket includes a first annular pocket and a second annular pocket. The restrictor is disposed in the first annular pocket and is capable of restricting shrinkage of the first annular pocket to a predetermined diameter range, if the seal is exposed to a temperature within a predetermined temperature range. The spring energizer is disposed in the second annular pocket and is configured to supply a force against the annular jacket to maintain the seal against a contact surface.

Abstract: An electromechanical actuator is provided for converting rotary action into linear action, and includes an electric motor, a cable yoke, an output shaft, and a pair of cables. The electric motor is adapted to be selectively energized and is configured, upon being energized to generate a drive torque. The cable yoke is coupled to receive the drive torque and is configured, upon receipt thereof, to rotate about a rotational axis. The output shaft is coupled to receive a drive force and is configured, upon receipt thereof, to translate along a linear axis that is disposed at least substantially perpendicular to the rotational axis. Each cable is wound, in pretension, on a portion of the cable yoke and around a portion of the output shaft. The pair of cables is configured, upon rotation of the cable yoke, to supply the drive force to the output shaft.

Abstract: A gas control valve is configured to controllably supply propellant gas to a thruster so that the thruster may produce thrust over a relatively wide range, and so that the thruster exhibits relatively fine minimum impulse bit (MIB) performance. The gas control valve includes a pilot stage having a pilot valve, and a main stage having a main valve. The gas control valve responds to control signals supplied to the pilot stage and is configured such that for commands of relatively short duration, only the pilot valve responds. Conversely, for commands of relatively longer duration, the pilot valve and main valve both respond.

Abstract: A gas thruster is configured to supply thrust over a relatively wide range, from a relatively low value to a relatively high thrust value, and exhibits relatively fine minimum impulse bit (MIB) performance. The gas thruster includes a thrust nozzle, a main stage, a main valve element, and a pilot valve. The gas thruster responds to thruster control signals supplied to the pilot valve and is configured such that for commands of relatively short duration, only the pilot valve responds and relatively low thrust is produced. Conversely, for command or relatively longer duration, the pilot valve and main valve element both respond and relatively higher thrust is produced.

Abstract: A gas valve apparatus is provided. A primary valve includes a flapper nozzle valve and first and second outputs. A secondary valve includes a housing having first and second inputs coupled to the first and second outputs of the primary valve, first and second seats coupled to the first and second inputs, first and second nozzles coupled to the first and second seats, and a moveable element configured for alternatively sealing the first and second nozzles as the moving element comes into contact with the first and second seats.

Abstract: An active pilot inceptor system includes a pilot inceptor, a multi-phase motor, and a motor control. The pilot inceptor is configured to receive user input and is operable, in response to the user input, to move to a control position. The multi-phase motor is coupled to the pilot inceptor to selectively supply haptic feedback thereto. The motor control is operable to selectively energize the multi-phase motor in a manner that causes the multi-phase motor to generate torque and supply the haptic feedback to the inceptor, and to selectively energize the multi-phase motor in a manner that the multi-phase motor does not generate torque.