A pump module with a casing having at least one pump piston is mounted in a reciprocatingly movable manner and may include a sealing element which, in pumping operation, abuts in a sealing manner against a cylinder. An embodiment of a pump module, which is easy to produce and can be disinfected or sterilized in a simple manner, includes a pump piston that can be fixated in a parking position in which the sealing element does not abut against the cylinder.

A pump module with a casing having at least one pump piston is mounted in a reciprocatingly movable manner and may include a sealing element which, in pumping operation, abuts in a sealing manner against a cylinder. An embodiment of a pump module, which is easy to produce and can be disinfected or sterilized in a simple manner, includes a pump piston that can be fixated in a parking position in which the sealing element does not abut against the cylinder.

A piston compressor for compressing a gas, which optionally can be disconnected from a drive device by a clutch, has an inlet valve, which is arranged between an inlet line for gas to be compressed and a compression chamber of the piston compressor, and an outlet valve, which is arranged between the compression chamber of the piston compressor and an outlet line for compressed gas. The piston compressor includes a closing device which closes the outlet line with respect to the compression chamber.

In some implementations, a controller may obtain an indication of a first crank angle associated with a first pump, of a dual-pump single-power source system, that is mechanically connected to a power source of the dual-pump single-power source system via a first clutch. The controller may obtain an indication of a second crank angle associated with a second pump, of the dual-pump single-power source system, that is mechanically connected to the power source via a second clutch. The controller may determine that a difference between the first crank angle and the second crank angle is outside of a tolerance of a crank angle difference value. The controller may modulate a fluid pressure associated with at least one of the first clutch or the second clutch to cause the difference between the first crank angle and the second crank angle to be within the tolerance of the crank angle difference value.

A device may include a driving mechanism, a clutch brake assembly and a fracturing apparatus, where the clutch brake assembly includes a housing, an input shaft, an output shaft, a clutch mechanism and a brake mechanism; the clutch mechanism and the brake mechanism are respectively disposed at two sides in an axial direction of the clutch brake assembly, and are sheathed on the output shaft; one end of the input shaft is connected with the driving mechanism; the other end of the input shaft penetrates into the housing and is respectively connected with the clutch mechanism and one end of the output shaft; and the other end of the output shaft penetrates out of the housing to be connected with the fracturing apparatus. When the fracturing apparatus stops operating, the driving mechanism can continuously operate, a condition of topspeed brake can be avoided.

A connection system for a plunger pump device, includes: a connector, including a shaft and first and second engaging portions provided at opposite end portions of the shaft; a reduction gearbox interface including a third engaging portion; and a plunger pump device interface including a fourth engaging portion. The first engaging portion engages with the third engaging portion to form a first engaging pair, and the second engaging portion engages with the fourth engaging portion to form a second engaging pair. The first and third engaging portions are respectively internal teeth and external teeth of the first engaging pair, or are respectively external teeth and internal teeth of the first engaging pair. The second and fourth engaging portions are respectively internal teeth and external teeth of the second engaging pair, or are respectively external teeth and internal teeth of the second engaging pair.