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.

An electronically commutated hydraulic machine is coupled to a drivetrain. Working chambers of the hydraulic machine are connected to low and high pressure manifold through electronically controlled valves. The phase of opening and closing of the valves has a default. In order to avoid cycle failure due to acceleration events, for example due to backlash in the drivetrain, the phase of opening or closing of the electronically controlled valves is temporarily advanced or retarded from the default timing.

A control system and method of a VFD-based pump. The control system controls an electric motor via a VFD, and the electric motor drives the pump. The control system comprises: an anti-ripple injection module for injecting an anti-ripple signal into a control path, the anti-ripple signal causing pressure ripples in the pump output to be at least partially cancelled. Further a pump system, comprising: a VFD, an electric motor, and a pump, wherein the VFD comprises the control system stated above.

A system for feeding and pumping of less pumpable material in a conduit line (28) is disclosed, comprising at least one main pump (10) for feeding of said less pumpable material into the conduit line (28), and a receiver unit (50) for receipt of the less pumpable material from the conduit line (28), wherein one or more independent driven compensators (40) are included in the conduit line (28) to maintain stable flow, said one or more compensators (40) being a fillable chamber (14;70) adapted to controllably being pressurized for additional feeding of the material through the conduit line.

A device and method for monitoring the health of a positive displacement hydraulic machine obtain dynamic pressure signals corresponding to steady state operation of the machine, and analyze, in the frequency domain, dynamic pressure amplitudes of the obtained dynamic pressure signals. It is determined that the hydraulic machine is damaged or worn if the amplitudes of the dynamic pressure signals at non-pumping frequencies exceed prescribed thresholds.

An estimation device comprises: an oscillation section configured to superimpose an oscillation signal for oscillating a valve body of a vacuum valve provided between a vacuum pump configured to pump gas from a chamber and the chamber on an opening degree signal for driving the valve body; and an estimation section configured to estimate, based on a pressure response of a chamber internal pressure upon oscillation, a pumping characteristic regarding the gas pumped through the vacuum valve.

Systems and methods are disclosed of monitoring performance of an incompressible fluid system. The system has a positive displacement pump and a high bandwidth pressure sensor. A method comprises sensing a pressure of the fluid with the pressure sensor, determining pump ripple frequency and hence the speed of the positive displacement pump, calculating the pump flow rate, determining a flow restriction of the fluid system based on the pressure and flow, and assessing or trending the fluid system flow restriction.

An anti-ripple injection method for injecting an anti-ripple signal into a control system of a pump is disclosed. The control system controls an electric motor via an electric motor drive, and the electric motor drives the pump. The anti-ripple signal causes pressure ripples in the pump output to be at least partially cancelled. The anti-ripple injection method includes: injecting an anti-ripple signal of any waveform into the control system, the anti-ripple signal being represented by the following equation: f()=.sub.mA.sub.m cos(m+.sub.m), wherein is the rotation angle of the motor shaft, m is the order of a signal harmonic in the anti-ripple signal, A.sub.m and .sub.m are parameters with respect to the m.sup.th signal harmonic. A control system of a pump including the anti-ripple injection apparatus, and a pump system including the control system are also disclosed.

A pumping system for compressible fluids comprises a first pump having a first pump outlet and a second pump having a second pump outlet. The first pump outlet and the second pump outlet merge in a junction which is in fluid communication with a main outlet. The pumping system further comprises a control to regulate the output pressure of the second pump on the basis of a measurement of the output pressure of the first pump. The corresponding method of operating a pumping system is also disclosed.

A natural gas pumping system that includes a reciprocating compressor having at least two cylinders, a first conduit in fluid communication with an outlet of the first cylinder, a second conduit in fluid communication with an outlet of the second cylinder, and a junction in fluid communication with the first conduit and the second conduit.