Provided is a reciprocating compressor including a third-stage compression unit, a fifth-stage compression unit, a drive unit, a discharge mechanism, a pressure sensor, and a discharge control unit. The discharge mechanism is capable of discharging hydrogen gas from a second connection pipe that allows hydrogen gas to flow to be suctioned into the third-stage compression unit. The discharge control unit controls the discharge mechanism to discharge the hydrogen gas from the second connection pipe when pressure of the hydrogen gas detected by the pressure sensor is higher than a set value preset.

Provided is a reciprocating compressor including a third-stage compression unit, a fifth-stage compression unit, a drive unit, a discharge mechanism, a pressure sensor, and a discharge control unit. The discharge mechanism is capable of discharging hydrogen gas from a second connection pipe that allows hydrogen gas to flow to be suctioned into the third-stage compression unit. The discharge control unit controls the discharge mechanism to discharge the hydrogen gas from the second connection pipe when pressure of the hydrogen gas detected by the pressure sensor is higher than a set value preset.

A cylinder in a compression stage is provided with a first cooling channel through which a cooling fluid for absorbing heat generated between the cylinder and a first piston ring group flows, a second cooling channel through which a cooling fluid for absorbing heat generated between the cylinder and a second piston ring group flows, and a through hole penetrating a side wall of the cylinder in an intermediate part between the first cooling channel and the second cooling channel A hydrogen gas leaking from a compression chamber to the intermediate part through between the cylinder and a piston and then guided to a leak line. The leak line includes a piping part and a volume expansion unit in which volume in a predetermined distance range is larger than volume of the piping part at the same distance range as the predetermined distance range.

A variable-pressure air pump includes a first cylinder with a first chamber and a second cylinder with a second chamber movably connected with one another. The second chamber fluidly communicable with the outside of the variable-pressure air pump selectively. A discharge device includes a connecting member and a switch movably connected with one another. The connecting member defines at least one discharge hole fluidly connecting with the second chamber. The switch has at least one flow guide portion and at least one blocking portion. The switch is movable between a first position in which the at least one flow guide portion is adjacent and opens to the at least one discharge hole and a second position in which the at least one blocking portion is adjacent to and blocks the at least one discharge hole.

Described is a multi-stage pump having at least two stages. The multi-stage pump includes a first pump stage and a second pump stage each having a chamber of different diameter and volume. The multi-stage pump also includes a plunger having first and second plunger sections. The first plunger section has a first plunger diameter, a first end configured for coupling to a drive mechanism, and a second end opposite to the first end. The second plunger section has a second plunger diameter that is less than the first plunger diameter, a third end in contact with the second end of the first plunger, and a fourth end opposite the third end. Movement of the plunger produces a displacement volume for the first chamber that is different than a displacement volume produced for the second chamber. The multi-stage pump can be configured in different operational modes to provide different flow rates.

Described is a multi-stage pump having at least two stages. The multi-stage pump includes a first pump stage and a second pump stage each having a chamber of different diameter and volume. The multi-stage pump also includes a plunger having first and second plunger sections. The first plunger section has a first plunger diameter, a first end configured for coupling to a drive mechanism, and a second end opposite to the first end. The second plunger section has a second plunger diameter that is less than the first plunger diameter, a third end in contact with the second end of the first plunger, and a fourth end opposite the third end. Movement of the plunger produces a displacement volume for the first chamber that is different than a displacement volume produced for the second chamber. The multi-stage pump can be configured in different operational modes to provide different flow rates.

A high pressure gas lift compressor system and method of using the system for supplying compressed gas to multiple wells are provided. The system includes a compressor having multiple compressor cylinders. Each cylinder has its own gas inlet line and dedicated gas outlet line that supplies compressed gas from that cylinder directly to a wellbore to provide artificial gas lift. Each cylinder also has its own control valve upstream of the cylinder to control the suction pressure to the cylinder. A desired gas flow rate to each well may be input, and the control valve is adjusted accordingly to achieve the flow rate. By inputting a flow rate for each separate cylinder, the flow rate to each well may be independently controlled.

A variable-pressure air pump includes a first cylinder with a first chamber and a second cylinder with a second chamber movably connected with one another. The second chamber fluidly communicable with the outside of the variable-pressure air pump selectively. A discharge device includes a connecting member and a switch movably connected with one another. The connecting member defines at least one discharge hole fluidly connecting with the second chamber. The switch has at least one flow guide portion and at least one blocking portion. The switch is movable between a first position in which the at least one flow guide portion is adjacent and opens to the at least one discharge hole and a second position in which the at least one blocking portion is adjacent to and blocks the at least one discharge hole.

A variable-pressure air pump includes a first cylinder with a first chamber and a second cylinder with a second chamber movably connected with one another. The second chamber fluidly communicable with the outside of the variable-pressure air pump selectively. A discharge device includes a connecting member and a switch movably connected with one another. The connecting member defines at least one discharge hole fluidly connecting with the second chamber. The switch has at least one flow guide portion and at least one blocking portion. The switch is movable between a first position in which the at least one flow guide portion is adjacent and opens to the at least one discharge hole and a second position in which the at least one blocking portion is adjacent to and blocks the at least one discharge hole.

An integrated air supply unit comprises a compressor housing, a pressure control unit (PCU) body, and a desiccant housing extending between the compressor housing and the PCU body. The desiccant housing defines a desiccant cavity holding a desiccant container for removing moisture from air passing therethrough. A piston is slidably disposed within a piston bore of the compressor housing. The PCU body defines a plurality of fluid passages with solenoid valves selectively controlling airflow therethrough. The integrated air supply unit may also comprise: a manifold, a discharge control valve, a compressor supplying pressurized air in a first pressurized air passage, a dryer configured to remove moisture from the pressurized air in the first pressurized air passage and to supply dried pressurized air in a second pressurized air passage, a supply control valve to control airflow between the second pressurized air passage and the manifold, and a piloted exhaust valve.