An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor. The controller is further configured to output an instruction to output the calculated pump displacement control current to the axial piston pump in order to control the displacement of the axial piston pump.

In a pressurized cleaning apparatus comprising a pressure generation unit for pressurizing a fluid, in particular for supplying a pressurized fluid via a hose attachment, preferably via a hand-held pistol or a spray nozzle, an operating unit is provided that is designed to make it possible to set a maximum operating pressure of the pressure generation unit at which the pressure generation unit is deactivated.

A pump for the transfer a predetermined total volume of fluid from a pump inlet to a pump outlet in a unit of time is calibrated by deriving a count of the number of times a volume of the fluid is transferred from a pump inlet to a pump outlet in a unit of time; and adjusting the number of times the volume is transferred in a unit of time until the derived count is substantially equal to a predetermined threshold value.

A system for measuring pump efficiency includes a pump configured to pump a fluid, a suction pipe disposed upstream of a suction side of the pump, a discharge pipe disposed downstream of a discharge side of the pump, a first pipe section disposed between the suction pipe and the suction side of the pump, and a second pipe section disposed between the discharge pipe and the discharge side of the pump. Each of the first pipe section and the second pipe section includes a temperature sensing pipe liner configured to measure a temperature of the fluid in the first pipe section, and a thermal insulator disposed radially outward of the temperature sensing pipe liner.

The present invention is directed to a minimum pressure valve comprising a housing (13) with a valve inlet (11) and a valve outlet (12) which are connected by means of a chamber (16), said minimum pressure valve (10) further comprising a valve body (17) movable in said chamber (16) between a closed position in which said valve inlet (11) is closed off, and an open position in which said valve inlet (11) is open, whereby said minimum pressure valve (10) further comprises a regulation unit (18) for setting the value of the pressure at which the valve body (17) moves into an open position.

Provided is a tube pump system which includes: a pair of roller units which are rotated around an axis line from a closing position to a releasing position; a pair of drive units which are configured to respectively rotate the pair of roller units; a control unit which is configured to control each of the pair of drive units; and a pressure sensor which is configured to detect a pressure of a liquid in a pipe connected to the other end of the tube, wherein the control unit controls a first rotation angle when the first roller unit passes through the closing position and a second rotation angle when the second roller unit passes through the releasing position such that fluctuation of the pressure of the liquid when the pair of roller units are rotated through at least one revolution falls within a predetermined value.

A centrifuge system includes a centrifuge and a feed line fluidly connected to centrifuge with the centrifuge driven by a hydraulic system. The hydraulic system includes an electric motor driving a hydraulic pump connected to a fluid reservoir with the hydraulic pump providing hydraulic fluid to one or more hydraulic motors which in turn rotate the centrifuge. The system includes a pressure sensor for measuring fluid pressure and a speed sensor for measuring the rotational speed of the centrifuge. A controller can be in communication with the hydraulic system and the sensors and can receive measurements from the sensors and adjust the pressure of hydraulic fluid flowing to the one or more hydraulic motors to maintain a rotational speed of the centrifuge based on differing loads. The system can include one or more valves, controlled by the controller, which can also adjust the hydraulic pressure of the system.

A decompression system is configured to: determine a regulating amount of a flow regulating valve provided on a discharge flow path through which compressed gas flowing out from a gas generating device flows, the regulating amount being determined based on a pressure detected by a pressure sensor provided on the discharge flow path; correct the determined regulating amount based on a temperature detected by a temperature sensor provided on the discharge flow path; and control the flow regulating valve so that the regulating amount thereof becomes the corrected regulating amount.

There is provided an air pressure system for controlling an air compressor in real time in accordance with the actual usage of compressed air by a plurality of terminals. Furthermore, in case pressure losses change abruptly, unwanted electric power is prevented from being consumed by a stable operation free of response delays on the basis of a predicted model that assesses time lags of volume responses. There is provided an air pressure system for supplying compressed air discharged from an air compressor through an air tank and a piping system to a plurality of terminals that consume the compressed air, including a compressor pressure sensor for measuring the pressure of compressed air discharged from the air compressor, a plurality of terminal pressure sensors for measuring the pressures of compressed air supplied respectively to the terminals, a flow rate difference calculating device for calculating deviation information on the basis of a capacity of the air tank, information on the piping system, the pressure of compressed air discharged from the air compressor, and the pressures of compressed air supplied respectively to the terminals, and a control device for controlling operation of the air compressor on the basis of the deviation information.

A fracturing apparatus may include a power supply platform; a gas turbine engine; a generator; and one or more rectifiers. At least two of the gas turbine engine, the generator, and the one or more rectifiers are arranged on the power supply platform. A first end of the generator is connected to the gas turbine engine. A second end of the generator is connected to the one or more rectifiers. The generator is configured to output a voltage to the one or more rectifiers.