A multi-piston fluid pump system includes a pump head, a motor unit, and a processor, the pump head having two or more cylinders and a piston disposed within each cylinder, the motor unit configured to provide bi-directional actuation of the pistons in each cylinder in response to control signals from the processor in order to minimize fluctuations in pressure and/or flow rate at the outlet of the fluid pump system.

A solvent supply system for supplying a composite includes a first supply path with a first pump unit, the first supply path being adapted for supplying a first solvent to a mixing unit, the first pump unit operating periodically, and a second supply path with a second pump unit, the second supply path being adapted for supplying a second solvent to the mixing unit, the second pump unit operating periodically. The mixing unit is adapted for mixing the first and the second solvent and for supplying a composite solvent. The solvent supply system further includes a control unit adapted for controlling operation of the first and the second pump unit.

The bellows pump device supplies pressurized air to one air chamber of two hermetic air chambers thereby to cause a bellows to perform expansion operation to suck a transport fluid, and supplies pressurized air to the other air chamber thereby to cause the bellows to perform contraction operation to discharge the transport fluid. The bellows pump device includes: an electropneumatic regulator configured to adjust a first air pressure of the pressurized air to be supplied to the one air chamber, and a second air pressure of the pressurized air to be supplied to the other air chamber; and a control unit configured to control the electropneumatic regulator such that, at least at a time point of end of expansion during expansion operation of the bellows, the first air pressure is lower than the second air pressure.

A method is provided for actively compensating for pressure changes of a working fluid within a conduit. A first cavity is provided in fluid communication with the conduit. A second cavity is in fluid communication with a control fluid. A plunger is in communication with both the first cavity and the second cavity and is movable in response to pressure changes of the working fluid in the conduit. The plunger is re-centered. Re-centering the plunger includes the following steps. Position data representative of movement of the plunger is collected. The position data is analyzed with a control unit to determine an average position of the plunger which is offset relative to a center position. The average position of the plunger is compared, with a control unit, to the center position. A signal is relayed from the control unit to a control valve to urge the plunger toward the center position.

A high pressure pump including a linear actuator having a servo motor to axially rotate a hollow rotor shaft in alternating directions, the servo motor having a stator positioned co-axially around the hollow rotor shaft with an interior of the rotor shaft being co-axially coupled to a drive member to convert axial rotation into reciprocal displacement, the drive member being constrained against linear movement and supporting a shaft. At least one piston is coupled to the shaft and the piston is arranged within a cylinder to define a pumping chamber, whereby alternating rotation of the rotor shaft causes reciprocal linear displacement of the piston to pressurize fluid in the pumping chamber. A drive mechanism includes a controller coupled to a servomotor and an encoder to measure movement of the hollow rotor or output shaft and send a feedback signal proportional to the movement to the controller.

A bellows pump device includes first and second bellows mounted on a pump head so as to be expandable/contractible independently of each other and configured to suck a fluid from a suction passage thereinto by expansion thereof and discharge the fluid therefrom to a discharge passage by contraction thereof. First and second air cylinder portions are configured to respectively cause the first and second bellows to perform expansion/contraction operation. First and second detection devices are configured to detect expanded/contracted states of the first and second bellows, respectively. A control unit is configured to control drive of the first and second air cylinder portions on the basis of each of detection signals of the first and second detection devices such that, before one bellows comes into a most contracted state, the other bellows is caused to contract from a most expanded state.

High pressure pump systems with reduced pressure ripple for use with waterjet systems and other systems are described herein. A pump system configured in accordance with a particular embodiment includes four reciprocating members operably coupled to a crankshaft at 90 degree phase angles. The reciprocating members can include plungers operably disposed in corresponding cylinders and configured to compress fluid (e.g., water) in the cylinders to pressures suitable for waterjet processing, such as pressures exceeding 30,000 psi.

The disclosure provides a method for monitoring a pumping system, comprising measuring the speed of a motor of the pumping system, wherein the pumping system further comprises a first pump and a second pump, wherein a control system is configured to operate the pumping system; determining a timeout period, wherein the timeout period is dependent on the speed of the motor; measuring the speed of the first pump, the second pump, or both, wherein there is a hall-effect sensor coupled to each of the first pump and the second pump; determining a designated operating condition of the pumping system; and determining if the first pump, the second pump, or both are enabled to operate in relation to the designated operating condition.

A liquid feeding device includes a discharge channel, a pump part, a feeding pressure sensor, a non-discharge pressure sensor, a pre-compression part, and a pre-compression speed determination part. The pump part has plunger pumps connected in series or parallel. At least one of the plunger pumps is a closed pump in which communication with the discharge channel is disconnected during a non-discharge time. The pre-compression part causes the closed pump that is after the suction process for sucking the liquid into a pump chamber is completed and during the non-discharge time to execute a pre-compression process to perform a discharge operation until a non-discharge pressure is substantially the same as a feeding pressure based on output of the feeding pressure sensor and output of the non-discharge pressure sensor. The pre-compression speed determination part determines a pre-compression speed of the closed pump in the pre-compression process.

The disclosure provides a method for monitoring a pumping system, comprising measuring the speed of a motor of the pumping system, wherein the pumping system further comprises a first pump and a second pump, wherein a control system is configured to operate the pumping system; determining a timeout period, wherein the timeout period is dependent on the speed of the motor; measuring the speed of the first pump, the second pump, or both, wherein there is a hall-effect sensor coupled to each of the first pump and the second pump; determining a designated operating condition of the pumping system; and determining if the first pump, the second pump, or both are enabled to operate in relation to the designated operating condition.