Apparatus and methods for determining operational health of a pump. An example method may include commencing operation of a processing device to monitor operational health of a pump for pumping a fluid at a wellsite, wherein the pump may be a reciprocating pump. During pumping operations of the pump, the processing device may receive pressure measurements of the fluid at a fluid inlet manifold and/or a fluid outlet manifold of the pump, receive position measurements of fluid displacing members of the pump, detect irregular pressure measurements based on the received pressure measurements, determine operational phase of the pump based on the received position measurements, and determine which of fluid inlet and outlet valves of the pump is leaking based on operational phase during which the irregular pressure measurements are detected.

A monitoring system may include a strain gauge, a position sensor, and a torque sensor. The strain gauge may measure strain in a chamber of the pressure pump and generate a strain signal representing the strain measurement. The position sensor may measure a position of a rotating member and generate a position signal representing the position measurement. The torque sensor may measure torque in a component of the pressure pump and generate a torque signal representing the torque measurement. The torque measurement may be used with the strain measurement and the position measurement to determine a condition of the pressure pump.

An improved valve leak detection system. The improved valve leak detection system comprises a membrane pump defining a flow path arranged to be opened and closed by at least one valve, a measuring device, a comparator, and a signal generator. The measuring device is configured to determine a conductivity value between two points on the flow path of the membrane pump, one point arranged upstream of the at least one valve and the other point arranged downstream of the at least one valve. The measuring device measures the conductivity value when the at least one valve is closed. The comparator is configured to continuously monitor the conductivity value. The signal generator is arranged to provide an output signal when the conductivity value is indicative of a valve leak condition for a set number of measurements within a set period of time.

A pump including one or more pumping chambers, one or more drive mechanisms for driving the one or more pumping chambers and a logic arrangement. The first pumping chamber of the one or more pumping chambers has a first inlet check valve, a first outlet check valve and a first temperature sensor. The logic arrangement is configured to identify a leak by applying logic to at least resistance-data indicative of a resistance of the first pumping chamber to the driving and temperature-data at least based on output from the first temperature sensor.

A pump including one or more pumping chambers, one or more drive mechanisms for driving the one or more pumping chambers and a logic arrangement. The first pumping chamber of the one or more pumping chambers has a first inlet check valve, a first outlet check valve and a first temperature sensor. The logic arrangement is configured to identify a leak by applying logic to at least resistance-data indicative of a resistance of the first pumping chamber to the driving and temperature-data at least based on output from the first temperature sensor.

A medical fluid pumping system includes a medical fluid pump for pumping a process fluid, the medical fluid pump including a first pump chamber, a first inlet valve chamber including a first inlet valve diaphragm, a first outlet valve chamber, a second pump chamber, a second inlet valve chamber including a second inlet valve diaphragm, and a second outlet valve chamber; and a medical fluid chassis operable with the medical fluid pump, the medical fluid chassis including a motive fluid source providing motive fluid at a motive fluid pressure, and wherein the first and second inlet valve diaphragms are configured to actuate from an open to a closed position at a pressure less than the motive fluid pressure to mitigate process fluid backflow through the first and second inlet valves.

A blood treatment system includes (i) a blood pump including a first blood pump chamber operable with a first inlet valve and a first outlet valve, and a second blood pump chamber operable with a second inlet valve and a second outlet valve; (ii) an arterial blood line; (iii) a dialyzer placed in fluid communication with the arterial blood line, wherein the blood pump is provided along the arterial blood line upstream of the dialyzer; and (iv) a venous blood line extending downstream from the dialyzer. The system also includes a processor configured to sequence the first and second blood pump chambers so as to achieve a pulsatile pattern of filling the first and second blood pump chambers and an at least substantially constant pattern of discharging blood from the first and second blood pump chambers to the dialyzer.

A monitoring system may include a strain gauge, a position sensor, and a torque sensor. The strain gauge may measure strain in a chamber of the pressure pump and generate a strain signal representing the strain measurement. The position sensor may measure a position of a rotating member and generate a position signal representing the position measurement. The torque sensor may measure torque in a component of the pressure pump and generate a torque signal representing the torque measurement. The torque measurement may be used with the strain measurement and the position measurement to determine a condition of the pressure pump.

A gas leak determining method for a multi-stage compressor including: a first compressing unit that compresses a gas; and a second compressing unit that further compresses the gas compressed by the first compressing unit includes: a step of calculating a proportion of discharge pressure from the second compressing unit to discharge pressure from the first compressing unit or suction pressure into the second compressing unit; and a step of determining that a gas is leaking from the second compressing unit when the proportion becomes equal to or less than a set value.

A liquid feeding device includes a primary plunger pump; a secondary plunger pump connected downstream; a check valve provided between the primary plunger pump and the secondary plunger pump; a primary pressure sensor that detects a pressure in the pump chamber of the primary plunger pump; a liquid feeding control part configured to control operations of the primary plunger pump and the secondary plunger pump; and a liquid leakage detector configured to detect liquid leakage in the check valve based on a change in an output value of the primary pressure sensor during the waiting time. The liquid feeding control part is configured to control the operation of the primary plunger pump so that a waiting time, where the primary plunger pump stops without operating, is present while a discharge operation by the secondary plunger pump is performed after a suction by the primary plunger pump is completed.