The present invention teaches a gearbox expansion cap that allows a gearbox unit to breathe to atmosphere while preventing the ingress of water or other materials into the gearbox or gearbox oil. According to a first preferred embodiment, the expansion cap of the present invention includes a pressure relief plug to control gearbox pressures. Additionally, the present invention teaches air channels enclosed within a gearbox casting which mate with air channels provided within the expansion cap to channel air from the expansion cap into the atmosphere.

The present invention teaches a gearbox expansion cap that allows a gearbox unit to breathe to atmosphere while preventing the ingress of water or other materials into the gearbox or gearbox oil. According to a first preferred embodiment, the expansion cap of the present invention includes a pressure relief plug to control gearbox pressures. Additionally, the present invention teaches air channels enclosed within a gearbox casting which mate with air channels provided within the expansion cap to channel air from the expansion cap into the atmosphere.

The present disclosure pertains to a system configured to protect flows in piping systems using minimal spare components. Some embodiments may provide: a first piping subsystem configured to receive a portion of the input flow; a second piping subsystem configured to receive the portion of the input flow by substituting for the first subsystem; a test subsystem configured to detect whether each of the first and second subsystems is able to vent when at least one, in the each subsystem, of a respective pressure and a respective pressure rate satisfies first and second criteria, respectively; and first and second pilots configured to detect a maximum pressure and a maximum pressure rate, respectively, of the portion of the first and second subsystems.

The present disclosure pertains to a system configured to protect flows in piping systems using minimal spare components. Some embodiments may provide: a first piping subsystem configured to receive a portion of the input flow; a second piping subsystem configured to receive the portion of the input flow by substituting for the first subsystem; a test subsystem configured to detect whether each of the first and second subsystems is able to vent when at least one, in the each subsystem, of a respective pressure and a respective pressure rate satisfies first and second criteria, respectively; and first and second pilots configured to detect a maximum pressure and a maximum pressure rate, respectively, of the portion of the first and second subsystems.

A thermal relief device (1) is described comprising a housing (2) having an inlet (3) and an outlet (4) connected by a relief channel (5). Such a thermal relief device should have a simple construction. To this end a microporous structure (10) is arranged between inlet (3) and outlet (4).

The present invention relates to a pressure stabilizer (14) comprising a constant pressure chamber (10) to which 3 pipes are attached, namely an outlet pipe (13), located downstream of the pressure stabilizer (14), an inlet pipe (11) and a return pipe (12), both placed upstream of the pressure stabilizer (14). The pressure stabilizer (14) prevents hydraulic shocks, which can potentially damage hydraulic installations. The devices described in the state of the art do not allow to stabilize efficiently spiky pressure fluctuations by means of simple hydraulic systems. The present invention by means of the combined operation of a pressure reducing valve (2) and a relief valve (3), will eliminate the pressure peaks at the inlet of hydraulic installations.

The present invention relates to a pressure stabilizer (14) comprising a constant pressure chamber (10) to which 3 pipes are attached, namely an outlet pipe (13), located downstream of the pressure stabilizer (14), an inlet pipe (11) and a return pipe (12), both placed upstream of the pressure stabilizer (14). The pressure stabilizer (14) prevents hydraulic shocks, which can potentially damage hydraulic installations. The devices described in the state of the art do not allow to stabilize efficiently spiky pressure fluctuations by means of simple hydraulic systems. The present invention by means of the combined operation of a pressure reducing valve (2) and a relief valve (3), will eliminate the pressure peaks at the inlet of hydraulic installations.

A capacity control valve, which can efficiently discharge a liquid refrigerant and reduce the driving force of a compressor, includes: a valve main body (10) including a first communication passage (11), a second communication passage (12), a third communication passage (13) and a main valve seat (15a); a valve body (20) including an intermediate communication passage (29), a main valve part (21c) and an auxiliary valve part (23d); a solenoid (30) which drives a rod (36) having an auxiliary valve seat (26c); a first biasing member (43) which biases the main valve part (21c) in the valve closing direction thereof; and a second biasing member (37) which biases the main valve part (21c) in the valve opening direction thereof, and the rod (36) relatively moves to the valve body (20), and opens and closes the auxiliary valve part (23d).

This application discloses a bidirectional vent valve, a battery, and an electrical device. The bidirectional vent valve includes: a valve seat, where the valve seat is configured to form a gas duct, and the gas duct includes a first end and a second end; a bidirectional valve assembly, where the bidirectional valve assembly is movably disposed in the gas duct, and is configured to open or close the gas duct through movement relative to the gas duct; and a first elastic component, configured to exert a force on the bidirectional valve assembly to close the air duct, and, when an air pressure difference between the first end and the second end of the gas duct is greater than a first threshold, the bidirectional valve assembly is configured to overcome the force of the first elastic component to open the gas duct.

An overpressure control apparatus is used to control jets of high-pressure fracking fluid or other stimulation fluid released from a treatment flowline in cases of overpressure. The apparatus includes a collection tank and one or more valves, which can all be mounted on or integrated to a skid. The sizes and weights of the collection tank and the skid may help to keep the apparatus on the ground during an overpressure event. The apparatus can be provided with an offline testing system that allows an operator to close off the communication between the apparatus and the treatment flowline, and instead, pump a clean fluid such as water at high-pressure to test the proper functioning of the valve.