An apparatus and associated method for operating a pump. A flow controller executes computer instructions stored in memory that define a selected flow rate of the fluid flowing out of the pump based on a flow profile trajectory stored in memory and related to a parameter of the fluid. A motor controller executes computer instructions stored in memory that map the selected flow rate to a selected motor speed via a transformation function stored in memory, and that operate the motor at the selected motor speed.

A fracturing apparatus and a vibration reduction method thereof. The fracturing apparatus includes at least one fracturing unit and a processing device, the fracturing unit includes: a plunger pump; a low-pressure liquid inlet manifold; a high-pressure discharge manifold; a pressure detection device, configured to detect a pressure value of the low-pressure fluid in the low-pressure liquid inlet manifold; and a vibration detection device, configured to detect vibration intensity of the plunger pump, the processing device is respectively communicated with the plunger pump, the pressure detection device and the vibration detection device, and is configured to control the plunger pump according to the vibration intensity detected by the vibration detection device and the pressure value detected by the pressure detection device. The fracturing apparatus can improve the displacement stability and serve life of the plunger pump.

A piezoelectric ceramic air pump comprises: a pump body, a piezoelectric ceramic crystal diaphragm, air inlet and output valves, the piezoelectric ceramic crystal diaphragm being co-central-axially mounted on the pump body to construct a working pump chamber for the piezoelectric ceramic air pump; wherein the pump body is approximately tubular, with the diameter being much greater than the axial length, air inlet and outlet ports configured to communicate the working pump chamber with an external air passage are arranged at a position of a peripheral wall of the pump body; an air inlet and outlet component respectively laminates the air inlet and outlet valves onto the air inlet and outlet ports, such that the air inlet and outlet holes are in communication with the air inlet and outlet valves and the air inlet and outlet ports to form air inlet and outlet passages in communication with the external air passage.

A remote pump manager is provided. The remote pump manager includes pressure sensors or a depth sensor operating to determine the change in pressure of a pump, a flow sensor operating to determine flow rate of fluid exiting the pump, a power meter operating to determine power data related to operation of the pump, and a management device having a programmable logic controller and a display. The pressure sensors, the flow sensor and the power meter are in communication with the management device. The management device operates to determine pump efficiencies, wherein the programmable logic controller automatically determines pump efficiency data in response to receiving real time data from the pressure sensors, the flow sensor and the power meter and automatically delivers the pump efficiency data to the display for displaying the determined pump efficiency data.

A method for compressing a gas by means of a multi-stage piston compressor is disclosed, wherein, if an inlet pressure of a first compression stage exceeds a threshold value, the gas is at least partially, in particular completely, branched off before the first compression stage and fed to a second compression stage, which directly follows the first compression stage. A computing unit for performing the method to such a multi-stage piston compressor are further disclosed.

A testing system for pulsating pressure measurement of the pressure of a fluid in dynamic pressure service in a pipe system is disclosed. For example, the testing system can include an accelerometer mounted to an exterior of the pipe system. An analyzer can be provided for sampling and filtering data from the only one accelerometer. In addition, a computer can be provided for running an algorithm to convert the data from the only one accelerometer to data regarding the pressure of the fluid in the pipe system.

Technologies for use with a hot water recirculation system containing a hot water source, a flow sensor downstream from the source, a booster pump downstream from the sensor, and a plumbing fixture downstream from the pump are provided. The technologies enable a controller to couple to the sensor and the pump, and operate in a calibration mode and a control mode. Such operations can increase energy efficiency of the pump and increase operational longevity of the pump.

A pressure detection device of a liquid flow route includes; displacement detecting means that detects displacement of a peristaltically-actuated tube in the radial direction; pressure calculating means that is able to calculate blood removal pressure based on the displacement of the peristaltically-actuated tube; closed flow route forming means that is able to form a closed flow route which includes a portion at which the displacement detecting means is disposed; pressure changing means that is able to arbitrarily change the pressure in the closed flow route; pressure detection means that is able to detect pressure change in the closed flow route; and calibration curve acquiring means that is able to produce and acquire a calibration curve with which the displacement detecting means and the pressure calculating means are calibrated by a relationship between the pressure change detected by the pressure detection means and a detection value of the displacement detecting means.

A system includes a sensor and a controller for a refrigeration or HVAC system having a compressor. The sensor senses a temperature of the compressor during operation of the compressor. The controller is configured to determine a rate of change of the temperature relative to time and to perform one or more procedures to protect the compressor based on the rate of change of the temperature. The one or more procedures to protect the compressor include shutting down the compressor, throttling a pressure regulator valve of an evaporator associated with the compressor, adjusting an expansion valve associated with the evaporator, reducing speed of the compressor, and partially or wholly unloading the compressor.

The present invention relates to a liquid feeding apparatus capable of feeding a liquid with high accuracy. The liquid feeding apparatus includes a liquid feeder having a downstream side, a plunger, and a cylinder that is configured for aspirating and discharging a solvent when a plunger slides. The liquid feeding apparatus further includes a pressure sensor for the solvent to be discharged, a selector valve configured to switch between a plurality of solvents to be aspirated and discharged, and a controller configured to control the liquid feeder and the selector valve. The controller controls the selector valve in synchronization with an aspiration operation of the plunger so that a mixing ratio of the solvents changes, controls the plunger to cause the plunger to operate at first and second accelerations that are different from each other, and suppresses a fluctuation of the solvent to be aspirated by the plunger.