Changing a cumulative pumping rate of multiple pump units by adjusting individual pumping rates of the pump units, wherein each temporary dip or spike of an individual pumping rate of one of the pump units is automatically offset by a predetermined temporary adjustment of an individual pumping rate of another one or more of the pump units to thereby reduce effects of the temporary dip or spike on the cumulative pumping rate of the pump units.

A control device for a power machine includes a target circuit pressure specifying unit configured to specify a target circuit pressure of the hydrostatic continuously variable transmission, a measurement value acquisition unit configured to acquire an actual circuit pressure of the hydrostatic continuously variable transmission, a brake torque determination unit configured to determine a brake torque based on the target circuit pressure and the actual circuit pressure, and a pump control unit configured to control the hydraulic pump based on the brake torque. The brake torque is a torque consumed by the hydraulic pump.

Provided is a compressor including: a compressor body that has a motor and compresses air; an aftercooler for cooling the compressed air supplied from the compressor body; a dryer for dehumidifying the compressed air flowing out from the aftercooler; a drain discharge valve for discharging a drain from the dryer; a first pressure sensor for measuring air pressure downstream of the aftercooler; and a control device having a rotation-speed adjusting unit that drives the motor at second acceleration smaller than first acceleration, the first acceleration being rated acceleration of the motor, when a pressure value measured by the first pressure sensor is less than a first threshold value predetermined at startup of the motor.

A pressure boosting device increases pressure of a fluid flowing through a conduit (5) and includes a booster pump (2), a control device (12), controlling the booster pump (2), as well as a pressure sensor (8) arranged at the exit side of the booster pump (2) and connected to the control device. The control device (12) is configured to control the booster pump, in an operating region, in a start-stop operation, a switching off of the booster pump (2) when reaching an upper pressure limit value (P.sub.1) and a switching on of the booster pump (2) when reaching a lower pressure limit value (P.sub.2). The control device (12) is further configured in a start-stop operation to automatically adapt at least one pressure control parameter (P.sub.1, P.sub.2) of the control device (12) on the basis of the temporal course of at least one pressure value (P) detected by the pressure sensor.

An analysis method of absolute energy efficiency and relative energy efficiency of the compressed air system. For the compressed air system operating in a form of a single compressor, a gas flow rate and a corresponding operating power of the compressor operating in the single compressor model are measured under a specified flow rate. Meanwhile, influencing factors of the compressor operation are monitored. The absolute energy efficiency of the compressor is defined, and a curve of the absolute energy efficiency of the compressor varying with the operating time versus the above factors are plotted in a same coordinate system. Obtaining absolute energy efficiency data of the compressor in a corresponding state. By analyzing the absolute energy efficiency under corresponding conditions and based on the corresponding chart, the actual unit consumption of a given single compressor and its changing rule under different production and environmental operating conditions can be intuitively analyzed.

A diaphragm compressor having a compressor head with a hydraulic fluid plate having a fluid plate contact plane and a process fluid plate having a process plate contact plane, the plates forming a compression chamber when contact therebetween is established, the compression chamber being divided in an upper chamber and a lower chamber by a multi-layered diaphragm where a controller is configured for controlling an alternating movement of the multi-layered diaphragm towards the upper and the lower chambers respectively, a process fluid plate seal is positioned in a process fluid seal groove provided in the contact plane, the process fluid plate seal forms a process fluid seal between an upper side of the multi-layered diaphragm and the contact plane, and the process fluid plate includes a process fluid leak groove system fluidly connected to a process fluid plate leakage passage provided in the process fluid plate.

One or more techniques and/or systems are disclosed for a pumping system that includes a self-priming pump, a remotely coupled controller configured to operate the self-priming pump and other portions of the system, a discharge flow meter, and a bleed valve coupled to the self-priming pump. The system can be remotely accessed, programmed, and transmit data to a remote device. The bleed valve can comprise a loss of prime sensor in the body, and when the loss of prime is detected in the pump and/or the discharge flow meter detects a loss of flow, the pump and/or controller may be used to help re-establish prime in the pump by opening the relief outlet and operating the pump at an increased rate.

A method of driving a pump is used in a pressure-applying apparatus, the apparatus including a flow passage, a pump configured to impart pressure into the flow passage, an opening and closing valve configured to open and close the flow passage, a pressure detector configured to detect pressure in the flow passage, and an atmospheric air open valve configured to open an interior of the flow passage to atmospheric air. The method includes driving the pump after closing the opening and closing valve and opening the atmospheric air open valve, and evaluating a state of the pump, based on one of: the pressure detected by the pressure detector at a time at which a predetermined time period has elapsed after closing the atmospheric air open valve, and a time from closing of the atmospheric air open valve until detection of a predetermined pressure by the pressure detector.

A device is provided for controlling the load of a mobile fluid pump which at an exit side is coupled to an outlet conduit, including an assembly that is a mobile unit and that includes an inlet conduit that can be coupled to the outlet conduit, which inlet conduit branches into a first conduit part and a second conduit part. A controllable closing valve is accommodated in the first conduit part and a turbine is accommodated in the second conduit part. A pressure sensor is accommodated in the inlet conduit, the first conduit part or the second conduit part, further including a generator that is drivable by the turbine and a measurement and control circuit that can be coupled to the pressure sensor and the controllable closing valve.

A digital pressure switch is configured to be connected to a fluid pump. The digital pressure switch includes a pressure sensor configured to measure pressure inside a closed system, one or more relays configured to be connected to the fluid pump for activation and deactivation of the fluid pump, an amperage sensor configured to measure an amperage draw of an electric motor of the fluid pump, and a controller configured to process data from the pressure sensor and/or data from the amperage sensor and to activate or deactivate the motor of the fluid pump based on the data from the pressure sensor and/or the data from the amperage sensor, using the relays.