Abstract: The present invention relates to a regulating device (1) for control of flow and/or pressure, including a housing (3) enclosing a movable inner member (2) which is provided with a passage corresponding to the housing inlet. The inlet comprises at least two ports (4,5,6,7) which are spaced apart with a circumferentially equal distance, and the passage comprises apertures (8,9,10,11) positioned correspondingly. The inner member (2) is fitted with radial play inside the housing so that in operation a leakage of the liquid to be regulated will enter between the inner member and the housing so that these elements are in a floating relationship, whereby the inner member is relieved from radial forces in operation. The invention also concerns a dynamometer testing device.

Abstract: A pump testing apparatus includes a support structure having a first passageway having an inlet, an outlet, and an opening for receiving a pressure gauge, and a second passageway having an inlet, an outlet and an opening for receiving a vacuum gauge; a pressure gauge operatively connected with the opening of the first passageway; a vacuum gauge operatively connected with the opening of the second passageway; first valve means for controlling the flow of fuel from the inlet to the outlet of the first passageway; and second valve means for controlling the flow of fuel from the inlet to the outlet of the second passageway.

Abstract: There is provided a failure determination system for a continuously variable transmission of a belt type, which is capable of determining failure of control valves for performing speed varying operation, and enhancing maintainability. An ECU controls a transmission ratio of the transmission to a fixation-determining LOW-side range when the vehicle is standing. When the transmission ratio during stoppage of the vehicle is within a stop-time OD-side range if engine torque?OD-time DR-side reference torque and at the same time the transmission ratio<DN-side reference value hold, the ECU determines that the DR solenoid valve is faulty, and if the throttle valve opening?OD-side reference value, the transmission ratio?DN-side reference value, and at the same time a vehicle speed<OD-side reference value hold, the ECU determines that the DN solenoid valve is faulty.

Abstract: Methods, systems, and articles of manufacture consistent with the present invention provide for detecting a leak in a hydraulic fluid system having a reservoir and a conduit operatively connected to the reservoir. The fluid may reside in the reservoir, the conduit, or both. A current level of the fluid in the reservoir is sensed. A determination is made as to whether the current level is less than a leak detection level. When it is determined that the current level is greater than the leak detection level, a current temperature of the fluid is sensed and the leak detection level is updated based on the current temperature of the fluid so that thermal expansion of the fluid in the system is considered in detecting and isolating a leak.

Abstract: A circuit is used which includes: first and second channels having first and second input ports, respectively, and a third channel having an end where the first and second channel meet and are connected to the third channel. A first liquid to the first input port is supplied to generate a reference flow. A second liquid is supplied by the target pump to the second input port. An interface of the first and the second liquids joined in the third channel is inspected. The operation condition of the target pump is determined from a condition of the inspected interface. Pulsation in the flow supplied by the target pump is detected from waves in the interface visually inspected. The image of the interface may be magnified. Pulsation in the reference pump may be absorbed.

Abstract: A system and method enable monitoring of a mechanical condition of a reciprocating compressor. The compressor includes a compressor frame, a pressure chamber, and a pressure head. A plurality of tie bolts are secured between the compressor frame and the pressure chamber head. A sensor assembly is secured to one of the plurality of tie bolts. The sensor assembly includes an elongation member positioned to extend in concert with extension of one of the tie bolts. A sensor measures extension of the elongation member to thereby monitor cylinder pressure.

Abstract: A monitor for a pump. The monitor includes a regulation mechanism to monitor input power delivered to the pump. An estimated output power is compared to the input power over a period of time by a data processor of the monitor. In this manner, the monitor may be employed to establish a condition of a true output power of the pump. This may be of particular benefit in a multi-pump or other operation where direct measurement of pump output power is unavailable.

Abstract: A method of monitoring integrity of a pump. The method may include recording timing information of the pump during operation while simultaneously sampling acoustic data with a high speed equidistant acquisition mechanism or at a rate based on the speed of the pump in operation. The acquisition of acoustic data is followed by evaluation thereof. Such techniques may improve resolution of acquired data while substantially increasing processor capacity for evaluation. A pump integrity monitor for carrying out such techniques is also described.

Abstract: A positive displacement pump monitor. The monitor includes a sensor coupled to a housing of a pump for obtaining acoustic data therefrom. A proximity switch may be simultaneously used to keep real time timing information relative to the cycling of the pump. A data processor of the monitor may then be employed to analyze acoustic data and timing information to distinguish acceptable noise from leak information. An operator thereby may be warned of the presence of a leak in the pump.

Abstract: A method and device for evaluating the capacity of a compressor (1) by air being allowed to flow out from a pressure tank (3) through an opening of known geometry. Following a calculation, the quantity of evacuated air is obtained. After this, a compressor (1) pumps back up to the initial pressure in the pressure tank (3). The compressor capacity (1) is established by comparing the time it takes for the compressor (1) to pump back up to the initial pressure in the pressure tank (3) with the time it takes when an acceptable compressor (1) pumps the same quantity of air. By the compressor capacity (1) is here meant the quantity of air which the compressor (1) delivers per unit of time at a given compressor speed and counter-pressure.

Abstract: An automatic transmission control apparatus controls a gear position by engaging and disengaging multiple frictional elements. A hydraulic pressure detector detects hydraulic pressure applied to the frictional elements. A failure determiner determines a failure, i.e., a dual-engagement of the frictional elements in accordance with detection signals of the hydraulic pressure detector. The hydraulic pressure detector detects first and second hydraulic pressure applied to the plurality of frictional elements. The second hydraulic pressure is greater than the first hydraulic pressure. The failure determiner determines a failure in accordance with a detection signals of the first and second hydraulic pressure detected by the hydraulic pressure detector.

Abstract: The present invention provides a pressure alarm for use in conjunction with conventional pressure gauge unit systems, as a replacement pressure gauge and alarm, or as a pressure alarm system. The invention provides adaptable alarm feedback signals for an operator, preventing the unexpected loss of pressure when using a gas cylinder, pressure boiler, or other device. The invention provides an alarm that may be a visual, audible, electronic, or mechanical low-pressure alarm and may include a means of ordering replacement supplies or sending a warning message. A system controller and memory module prevents false alarms and eases the burden of the operator while allowing external input and control.

Abstract: A test stand and related method for testing a hydraulic oscillator cylinder having an oscillating drive includes gas-filled shock absorbers for reacting oscillating movement of the oscillating drive to simulate operational load conditions of the oscillator cylinder. The shock absorbers are mounted on a rigid structure and preferably abut an oscillating member mountable on the oscillating drive to react the oscillating movement thereof. The oscillating member may be disposed between a pair of rigid members on which the shock absorbers are mounted whereby one set of shock absorbers reacts movement of the oscillating member in one direction and another set reacts movement of the oscillating member in the opposite direction. Translating structure may extend between the oscillating member and oscillating drive and through a hole in one of the rigid members. Guide shafts may guide oscillating movement of the oscillating member. Gas pressure within the shock absorbers may be controlled.

Abstract: A method and apparatus for determining the operating health of a hydraulic system are provided. The method may include the steps of determining a plurality of operating parameters of the hydraulic system during operation of the hydraulic system, determining an estimated working condition value of the hydraulic system, modifying the estimated working condition value as a function of the operating parameters, and determining the operating health of the hydraulic system as a function of the working condition value. In one method, the working condition value may be indicative of an effective bulk modulus value of an operating fluid within at least part of the hydraulic system.

Abstract: The outlet pressure of a pump that fluctuates rapidly, as is typical of high pressure multiplex pumps, is sensed in a pressure line leading from the main flow line to a damping mechanism. The damping mechanism comprises a pair of small spaced openings, which are preferably adjustable in size. The damping mechanism is ideally a pair of needle valves placed in series so the pressure downstream of the second needle valve fluctuates considerably less than upstream of the first needle valve. The damped pressure is sensed to provide an input to real time graphs showing various pertinent pressure measurements involving the application of pressure, e.g. to monitor downhole tools in hydrocarbon wells. The downhole tools may be fluid driven motors, whipstocks, packers, wiper plugs and the like. In the case of fluid driven or mud motors, a base line pressure taken when the motor is idling is compared to the pressure when the motor is drilling to detect the onset of motor stall.

Abstract: In general, in one aspect, the invention relates to a method for determining a system integrity of an oilfield machine operatively coupled to a magnetic drive, wherein the magnetic drive is configured to provide a controlled operational speed, comprising adjusting a control on the oilfield machine such that the oilfield machine operates at a baseline speed, recording a raw system integrity measurement while the oilfield machine is operating at the baseline speed, and calculating the system integrity using the raw system integrity measurement and a baseline system integrity measurement.

Abstract: A liquid-ejection testing method includes the following steps (A) to (D): (A) A step of making at least two conductive detection members be opposed, in a non-contact state, to a plurality of liquid ejecting nozzles that are to be tested, the detection members being opposed in a direction that intersects with a direction in which the plurality of liquid ejecting nozzles are arranged, each detection member corresponding to a different liquid ejecting nozzle. (B) A step of ejecting a charged liquid from each of the plurality of liquid ejecting nozzles. (C) A step of detecting an induced current generated at each of the detection members by the liquid that has been ejected from each of the liquid ejecting nozzles (D) A step of judging whether or not ejection of the liquid is being properly performed for each of the plurality of liquid ejecting nozzles, based on a magnitude of the induced current that has been detected.

Abstract: This invention relates to an emergency valve shutdown system having an integrated test facility. The invention provides an apparatus for testing emergency shutdown valves in a process industry comprising: a valve having a plurality of limit switches each limit switch arranged to indicate that the valve has reached a corresponding one of a plurality of predetermined valve positions; a valve monitor module arranged to send a signal to said valve to initiate movement of said valve and to receive feedback relating to said limit switches; wherein said feedback is provided via a single feedback signal between the valve and the valve monitor module.

Abstract: A system for hemodynamic simulation comprises a vessel having properties of a blood vessel, a reservoir containing a quantity of fluid, tubing connecting the vessel and reservoir, and at least one pump for circulating the fluid within the system. Fluid can be tissue culture medium or blood analog fluid, and the vessel may include mammalian cells attached to its inside. A drive system, comprising two reciprocating drive shafts that are coupled by a cam, enables the uncoupling of pulsatile flow and pulsatile pressure to provide independent control over wall shear stress and circumferential strain. The shaft drives two pumps that are 180 degrees out-of-phase and are connected upstream and downstream of the vessel, and effect this uncoupling.

Abstract: An automatic pump testing device is configured with controller, a pump testing station, a supply tank and a collection tank. In accordance with one aspect of the present invention, a pump testing device is configured to test various types of hand actuated pumps. In accordance with another aspect of the present invention, the pump testing device is configured to test various end of life modes, length of life, and other pump performance information, including pump performance information measured over time.

Abstract: A method and apparatus for determining the operating health of a hydraulic system are provided. The method may include the steps of determining a plurality of operating parameters of the hydraulic system during operation of the hydraulic system, determining an estimated working condition value of the hydraulic system, modifying the estimated working condition value as a function of the operating parameters, and determining the operating health of the hydraulic system as a function of the working condition value. In one method, the working condition value may be indicative of an effective bulk modulus value of an operating fluid within at least part of the hydraulic system.

Abstract: A fluid flow control system for an electromagnetic pump having an electromagnetic drive (11) and a compressor (6). The control system established a required current in the compressor coils (10) to control the position and movement of the actuator (11), the actuator deflecting a diaphragm within the pump to provide the required flow. The control system includes a command signal generator (1) to create a signal representing the required flow. The signal is applied to a command processor (2) with any feedback signals (13) for example, coil current and/or actuator displacement. The command processor (2) calculates the appropriate drive signal defined by mark-space ratio, repetition rate, and amplitude. The drive signal controls the voltage supplied to the compressor coils (11) resulting in a required coil current to provide the desired flow. A dc power supply is used to avoid problems regarding main power supply and frequency.

Abstract: A pump testing apparatus is disclosed for testing output characteristics of a fluid flow exiting a pump. The apparatus includes a flow testing structure for testing characteristics of the fluid flow, a first chamber having an interior for receiving a fluid flow exiting the flow testing structure, and a second chamber having an interior for receiving fluid flow from the first chamber. The second chamber has an entrance opening for receiving fluid flow into the interior of the second chamber and a discharge opening for discharging fluid flow from the interior of the second chamber, the second chamber defining a convoluted path for the fluid flow between the entrance opening and the discharge opening. The apparatus also includes structures located in at least one of the first chamber and the second chamber for reducing a velocity of the fluid flow.

Abstract: A method and apparatus for analyzing a hydraulic pump in real-time. A pressure signal is provided representing a discharge pressure of the hydraulic pump, and the pressure signal is decomposed into a plurality of levels. Each of the plurality of levels has at least one frequency band. A feature pressure signal is located in at least one of the frequency bands and compared to a reference wavelet to determine if a fault exists in the hydraulic pump and/or a type of defect in the hydraulic pump.

Abstract: A diagnostic system, for a valve (2), having a sensor (12) that senses structure-borne noise and having a device (14) for evaluating a measurement signal (13) of the structure-borne noise. During a calibration process, a first progression of the measurement signal is sensed for the closed position of the valve (2) and a first value (w1) of a characteristic is determined. To simulate leakage noise, the valve (2) is nearly closed during operation, a second progression of the measurement signal is sensed and a second value (w2) is determined. If the deviation of the second value from the first value is sufficiently large, a diagnosis is possible. A third progression of the measurement signal is sensed for the closed position of the valve as in an installed condition, and a third value (w3) is determined. If the deviation of the third value (w3) from the first value (w1) is too great, and if a diagnosis has been identified as being possible, then the system deduces that the valve leaks.

Abstract: A method is provided for measuring a pressure of a hydraulic fluid that is supplied from a hydraulic fluid control device (1) to a operation device (6). The method includes measurement of a first pressure (Pm) and a second pressure (Pa). The first pressure is the pressure of the hydraulic fluid within a first flow path (P3 to P8) connecting a pressure control unit (3) and the operation device. The second pressure is the pressure of the hydraulic fluid within a second flow path (P11, P12) connecting an accumulator (22) and the pressure control unit. Then, a stabilization time (T) is determined. The stabilization time is the time when a pressure gradient per unit time of the second pressure become to be smaller than a predetermined value. Thereafter, a pressure (Pw) of the hydraulic fluid at the operation device is determined based on the first pressure that is measured at the stabilization time or at a time immediately after the stabilization time.

Abstract: The method for testing the function of an electrohydraulically controlled automatic transmission upon a testing stand by simulation of a vehicle operation provides that the output shaft of the transmission be connected with a stationary torque-measuring hub and be blocked thereby; the shifting elements existing in the transmission are tested when the output shaft is blocked with an input rotational speed which is precisely sufficient to supply with hydraulic pressure the pressure setting members for the shifting elements. As characteristic quantity can be used the setting member current at which the shifting element slips or at which the slip tends toward zero when the shifting element closes.

Abstract: A mixed air amount alarm device is provided which determines the amount of air present in a hydraulic circuit between a hydraulic pressure source and an instrument driven by hydraulic pressure, and produces an alarm if the air amount is excessive, a situation is prevented in which an alarm is produced or not produced according to change of the air amount (volume) resulting from temperature change, and it is possible to stop an alarm if potential danger disappears and a safe state is recovered due to spontaneous release of air out of the hydraulic circuit. If the air amount is determined excessive, this is stored in a nonvolatile memory, and even if air amount excessiveness determination is not made at the next activation of the hydraulic device, the content of the nonvolatile memory is checked and an alarm is produced if air amount excessiveness determination has not been made before.

Abstract: A sensor component that may be used in conjunction with a filter module may include a plurality of sensor packages. The latter, in turn, may incorporate one or more micro-electromechanical systems (MEMS) sensors to measure various characteristics of fluid flow and filtration. A single sensor component may be adapted to measure the pressure, temperature, flow rate, differential pressure, conductivity, viscosity, pH level, etc. of the fluid at an upstream and a downstream location. Sensor measurements may be obtained continuously in order to monitor and indicate fluid conditions, including the use of a warning mechanism to indicate an out-of-range condition when the measurements fall outside of pre-set limits. Depending on the application and the fluid being filtered, data, including measurement data, may be transmitted through electrical connections or wirelessly. In wireless configurations, a sleep-mode may be included to maximize the life of local power supplies.

Abstract: A displacement measuring device measures a path of a moving object that can be displaced in a direction has at least one first component that is allocated to the moveable object and a second, stationary component. The components are interlinked for the purpose of converting a movement and/or displacement of the moving object into an electrical signal. The displacement measuring device also has an evaluating device for converting the electrical signal into movement and/or position information. The displacement measuring device has a high degree of accuracy, is not susceptible to wear, is resistant to vibration, shocks, or corrosion and is economical to use in almost all media. To this end, the first component is a spring element connecting the moving object and the second component is a force-measurement device which releases an electrical signal corresponding to the force that is exerted on the spring element.

Abstract: An over-pressure protection system having a conduit section extending between a pressure reduction valve and a low-pressure fluid handling system, a shut-off valve provided with an actuator arranged in the conduit section, pressure sensors arranged one on either side of the shut-off valve in the conduit section, a safety control system that communicates with the actuator and the pressure sensors which produces a signal when it detects a high pressure in the conduit section, and a self-diagnostic system for checking the shut-off valve and the pressure sensors that communicates with the actuator, the pressure sensors and the safety control system, which self-diagnostic system produces a signal when it detects a failure in either the shut-off valve or the pressure sensors or both.

Abstract: A method and apparatus for early fault detection in a centrifugal pump equipped with a balancing device, where the balancing device has an axial gap and optionally at least one radial gap through which a balancing flow is conducted, and with a spring element which acts on the balancing device to hold open the axial gap. Reliable information regarding impending faults is obtained while largely using existing elements by measuring the deformation of the spring element (10, 14) during operation of the centrifugal pump (24), and starting from the pump characteristics of the centrifugal pump (24) and the spring constant of the spring element (10, 14), drawing a conclusion regarding the instantaneous operating state of the centrifugal pump based on the measured deformation.

Abstract: A system (10) controlling operation of a steam turbine (T). Sensors (12) measure dynamic pressure level variations in a stage (S1-Sn) of the turbine. A signal (Ps) from a sensor is converted to a frequency based signal (Fs). A comparator (16) compares the pressure levels at various frequencies as represented by the frequency based signal (Fs) to a matrix of limiting values including both alarm and trip signal limits. The control system provides an alarm to an operator of the steam turbine if the comparison indicates that an alarm limit has been exceeded, or takes the steam turbine off line, if a trip signal limit has been exceeded. This is done to prevent damage to the steam turbine. However, the control system maintains the steam turbine in operation if no aeromechanical disturbances or instabilities, as sensed by the sensors, has occurred.

Abstract: A portable electro-hydraulic test bed apparatus with analog control station and methodology for performing hands-on materials and components testing. A portable test bench is provided having a hydraulic pump and a reservoir of hydraulic oil. The pressurized hydraulic fluid flows through a pressure relief valve, filter, and ball valve to a servo control valve. The servo control valve controls the action of the hydraulic ram. Any return hydraulic fluid flows through check valve, filter, and heat exchanger back to the reservoir. The servo control valve with the hydraulic ram may be moved to the location where the test is to occur. Whenever the hydraulic ram is moved to a different location displacement interlock is also required. The hydraulic ram is anchored at one end and the test is performed on the test item with the other end of the ram. A displacement sensor is included to determine how much the test item is being displaced.

Abstract: A control device test system including an electrical switch and a device controller, wherein the device controller has a processor, a memory coupled to the processor, and an auxiliary input coupled to the processor and adapted to receive a binary signal from the electrical switch. A routine is stored in the memory of the processor and is adapted to be executed on the processor to cause a control device test to be performed in response to the receipt of the binary signal at the input.

Abstract: A flowmeter for metering the volume of flow of a fluid through a filter, to enable the level of filter usage to be indicated. A preset level of metered fluid flow volume indicates a corresponding level of filter usage. The flowmeter is able to self-generate current responsive to the flow of the fluid therethrough.

Abstract: The load element state detecting portion 72 detects the completion of the filling of the hydraulic oil into the clutch 62 and the working limit of the accumulator 64 on the basis of the displacement of the spool valve element 42. That is, since the completion of the filling of the hydraulic oil into the clutch and the working limit of the accumulator 64 are directly detected, so that the completion of the filling of the hydraulic oil into the clutch 62 and the working limit of the accumulator 64 can be detected with high precision regardless of differences among products and the time-lapse variation. Furthermore, they can be detected without equipping any special device to the hydraulic control circuit, and thus there is an advantage that the device construction is simple.

Abstract: The invention concerns a detector for detecting malfunction in a peristaltic pump wherein a flexible tubing (44) containing a fluid is locally compressed against a support part by rollers (32) mounted on a rotor (28) driven by a motor. Said detector is characterized in that it comprises: a ring (68) mounted sliding on the tubing between two extreme positions; driving means (64, 80, 84), actuated by the rotor, for subjecting said ring to a specific reciprocating motion between said positions; and detection means (74a, 74b, 84) reacting to an abnormal reciprocal motion by producing a warning signal.

Abstract: A test device (10) for filter systems comprising at least two test units (14), a management unit (12) for managing and controlling the at least two test units (14), and signal links via a bi-directional or multi-directional network (16) between the management unit (12) and the at least two test units (14), particularly for transmitting test program instructions and test results. The invention further relates to a method for testing filter systems and a computer readable storage device with a computer program stored therein for testing filter systems.

Abstract: A sensor component that may be used in conjunction with a filter module may include a plurality of sensor packages. The latter, in turn, may incorporate one or more micro-electromechanical systems (MEMS) sensors to measure various characteristics of fluid flow and filtration. A single sensor component may be adapted to measure the pressure, temperature, flow rate, differential pressure, conductivity, viscosity, pH level, etc. of the fluid at an upstream and a downstream location. Sensor measurements may be obtained continuously in order to monitor and indicate fluid conditions, including the use of a warning mechanism to indicate an out-of-range condition when the measurements fall outside of pre-set limits. Depending on the application and the fluid being filtered, data, including measurement data, may be transmitted through electrical connections or wirelessly. In wireless configurations, a sleep-mode may be included to maximize the life of local power supplies.

Abstract: Piezoelectric transducer assemblies that are useful for the monitoring of the gas output from a gas driven pump, wherein the assembly is not an integral part of the input or output flow stream of the material being pumped, but is used to monitor the exhaust gas flow of the gas driven pump.

Abstract: In a process for the monitoring of leakage in the hydraulic pressure area of a membrane pump, processing is in a manner such that the point in time (t3), at which the snifting process serving for leakage compensation is initiated, is monitored continuously and compared with a reference value (t1), where a predetermined deviation (&Dgr;t1-t3) between two values (t3 and/or t1) triggers a leakage display.

Abstract: Object of this invention is to provide an axial torsional vibration measurement device of the reactor internal pump capable of measuring the axial torsional vibration easily. The vibration detector 2 that detects vibration in the radial direction, and the sound detector 3 that detects vibration in the circumferential direction are fitted on cylindrical motor casing 6, which contains the motor of a reactor internal pump. The dimension of both signals of a vibration waveform signal detected by the vibration detector 2, and a sound waveform signal detected by the sound detector 3 are matched in vibration calculating device 15, to thereby obtain an axial torsion vibration of a motor from the difference of both signals.

Abstract: A valve and valve arrangement for a fire suppression system includes a remotely controlled valve such as a solenoid valve which is electrically controlled to provide a preselected flow through the remotely controlled valve corresponding to the flow through a single sprinkler head.

Abstract: A position sensor and a method for sensing a position of a moveable member includes at least first and second deflectable members arranged so as to allow the moveable member to pass therebetween and cause the at least first and second moveable members to deflect in proportion to the position of the moveable member relative to the first and second deflectable members. In one example of the present invention, the deflectable members are cantilever-mounted members extending in generally the same direction. The amount of resultant deflection is measured by any suitable means. For example, each deflectable member may have a Wheatstone bridge provided thereon acting as a strain gauge in a known manner, such that the strain detected is proportional to the amount of deflection. In a particular example of the present invention, some of the elements of a first Wheatstone bridge are provided on the first deflectable member and some are provided on the second deflectable member.

Abstract: A flow meter including at least one flow valve used to performance test system compressors is described. The flow meter includes a pressure vessel including at least one exit port. A flow valve is coupled to each vessel exit port, and each flow valve discharges fluid from the vessel at a pre-determined flow rate. The flow valve includes a first end, a second end, and a bore extending therethrough. The bore includes an entrance portion and an exit portion. The bore entrance portion is frusto-conical and curves outwardly from the bore exit portion such that a diameter of the bore entrance portion is variable and larger than a diameter of the bore exit portion.

Abstract: The wear resistance of impellers used in multi-stage turbine pumps is tested by using a multi-stage turbine pump having impellers with different physical properties to pump a fluid containing small amounts of an abrasive material. After the fluid has been pumped for a time period sufficient to provide measurable wear to the impellers, the impellers are inspected to determine their relative resistance to wear.

Abstract: A method for determining whether a centrifugal pump is operating within its normal flow operating range includes the steps: of determining a motor torque/TDH relationship over a range of speeds for a minimum flow rate in order to obtain a minimum flow operating range for the centrifugal pump; determining a motor torque/TDH relationship over a range of speeds for a maximum flow rate in order to obtain a maximum flow operating range for the centrifugal pump; determining the actual operating motor torque and TDH of the centrifugal pump at a given operating point; and determining whether the actual operating motor torque and TDH of the centrifugal pump fall within the minimum flow and maximum flow operating ranges of the centrifugal pump.

Abstract: A fluid pump system includes a pump having a plurality of cylinders, each having an outlet port coupled to a high-pressure manifold. A pressure transducer is coupled to the manifold and configured to convert pressure levels of fluid in the manifold to a voltage signal at an output of the transducer. The system further includes a digitizer configured to convert the voltage signal from the transducer to a digital signal at a digitizer output, such that when a value of the voltage signal is less than a selected reference voltage a first digital value is produced, and when the voltage level exceeds the selected reference voltage a second digital value is produced. A diagnostic circuit having an input coupled to the digitizer output is configured to detect malfunctions of the pump based upon characteristics of the digital signal.

Abstract: A sensor unit for a rotating shaft, which unit uses its inner opening directly in contact with the outer surface of the rotating sheft in order to precisely and repeatedly radially align a sensor to such shaft.