Abstract: An apparatus for indicating efficiency losses in a pump is provided. The apparatus includes a temperature sensor located at the pump input, a second temperature sensor located at a second location, a fluid flow sensor located at the second location, a processor for producing a difference signal in response to signals from the first and second temperature sensors and for quantifying efficiency losses of the pump in response to the difference signal and a signal from the fluid flow sensor. A fault indicator is also provided that is responsive to the efficiency losses.

Abstract: A whole-body plethysmograph having a calibration of the pressure gauge is provided, which includes an air tight, lockable cubicle for the reception of a person to be examined, a cubicle-pressure pressure gauge that responds to the interior pressure of the cubicle. A mouthpiece is provided with a valve, by means of which the respiratory air flow can be barred, and a closure-pressure pressure gauge is connected to the mouthpiece for measuring the pressure in the mouth of a person, as well as an evaluation unit connected to both the cubicle-pressure pressure gauge and the closure-pressure pressure gauge. A piston pump is connected to said cubicle, so as to be air tight. The piston pump is surrounded by the air tight box, to which the closure-pressure pressure gauge is, at times, connected for calibration and the pressure fluctuations generated by the piston pump are used to calibrate the cubicle-pressure pressure gauge and the closure-pressure pressure gauge.

Abstract: Apparatus for monitoring the health and response of critical electromechanical control valves to detect the likelihood of future valve malfunction includes the use of Fourier transform decomposition and time-domain wavelets to selectively enhance portions of the valve response signal for comparison with a normal valve response signal.

Abstract: An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor.

Abstract: An oil well pumping unit has a walking beam which raises and lowers a rod connected to a downhole pump. To perform well analysis, it is desirable to know the position of the rod during the stroke. An accelerometer is mounted on the pumping system unit to move in conjunction with the rod. An output signal from the accelerometer is digitized and provided to a portable computer. The computer processes the digitized accelerometer signal to integrate it to first produce a velocity data set and second produce a position data set. Operations are carried out to modify the signal and produce a position trace with stroke markers to indicate positions of the rod during its cyclical operation.

Abstract: A method and apparatus for testing a spring pack of a valve operator, the apparatus including a hollow housing with a coupling for attaching to the valve operator. A slider is received within the housing and moves therein when driven by a bolt that extends through a threaded aperture in the housing. A load sensor is attached to the slider and extends through the coupling and engages a valve operator component that is connected to the spring pack. As a technician turns the bolt, the apparatus compresses the spring pack within the valve operator and the load sensor produces an electrical signal that indicates how much force is exerted by the spring pack. At the same time, a transducer produces another electrical signal indicating the displacement of the spring pack.

Abstract: Method and apparatus for simulating operating conditions on a motor operated valve. The present invention provides a means for simulating actual operating load conditions, such as a simulated accident condition, for valves. An axial force is placed on the valve stem by a hydraulically operating loading system to simulate loading conditions associated with a postulated accident, and the valve operator is actuated. The response of the valve during the simulated loading condition is monitored to ensure that the valve is capable of operating, such as to close or open, in the event of an unusual condition.

Abstract: A strain sensor device is attached to a cylindrical structural member for measuring the amount of twist of the member about an axis of rotation and includes a central beam, which is aligned parallel to the axis of rotation of the structural member and is fastened in between two mounting members which are themselves fixedly secured to the structural member. When torsion occurs in the structural member, the one mounting member will move in a relative direction parallel to the other mounting member but offset by the length of the central beam. The central beam is significantly less rigid than the mounting blocks and bends to accommodate the movement. Four strain gauges are secured to the central beam in a bridge circuit to measure bending of the beam. The bridge circuit generates electrical signals proportional to the angle of twist and the torsional load on the structural member.

Abstract: The invention refers to a system for the technical safety check of solenoid valves, where during an operational switch of the solenoid valve, the induction current of the actuating magnet of the valve is recorded over time and stored as test function I=I(t). From the test function the control function I'=dI/dt is digitally calculated and after digital logarithmation also stored. Both functions may be displayed and evaluated simultaneously on the screen, which assures a better and more exact evaluation of the functional condition of the concerning solenoid valve, including any existing defects.

Abstract: Disclosed is apparatus and a system for measuring and monitoring the actual mechanical power being produced by an electric motor and measuring and monitoring the reactive torque acting on and the rotational speed of a drive shaft of the electric motor used to drive a valve actuator of a motor operated valve (MOV). The apparatus and system is comprised of a motor power measuring cell inserted between and bolted to the electric motor housing and to the valve actuator housing of commercial MOVs to provide continuous in-service valve and motor diagnostics. The motor power measuring cell is provided with a first measuring means for measuring the torque acting on the drive shaft and a second measuring means for measuring the rotational speed of the drive shaft.

Abstract: An apparatus for proof testing mechanical heart valve prostheses. The apparatus also provides an in vitro test environment simulating in vivo loads, providing a function test. If the heart valve passes the pivot proof test, a function test is performed. The apparatus first directs a pressurized back flow against the tested valve, closing the valve and applying pressure against the leaflet occluders well beyond the maximum functional in vivo load. The heart valve is positioned so that the leaflets assume their "worst-case" position, that is, the heart valve is oriented so that all the necessary play or gap between the leaflet pivots and pivot recesses is subsumed at one location, thus representing the most severe condition that might be experienced with a heart valve in use. The heart valve is loaded by back pressure applied through a working fluid. Pressure transponders detect the pressure on each side of the heart valve, to determine if a valid test has been performed.

Abstract: Disclosed is a diagnostic system for measuring and monitoring selected operating parameters of a solenoid operated valve. The valve assembly, comprised of a valve body, a valve plug attached to a valve stem is actuated or operated by a solenoid. The valve assembly is provided with one or more sensors attached to or positioned adjacent to the valve assembly to measure and monitor selected operating parameters of the valve assembly and provide electrical output signals indicative of the measurements to a signal conditioning, processing and data collection apparatus used to receive and record the electrical output signals. The diagnostic system allows the user of the valve to measure and monitor the various electrical and mechanical activities of the valve during its operation while in service and to see if the valve is operating within its design parameters.

Abstract: A torque/position transducer is positioned between the valve stem of a valve and a valve operator adapted to open and close the valve and includes a body including an input lug adapted for mating the engagement with the output lug of the valve operator and an output lug adapted for mating the engagement with the valve stem of the valve. A plurality of strain gauges are mounted on the body of the torque/position transducer and function to generate an output signal indicate of the amount of torque necessary to open or close the valve. The torque/position transducer further includes a movable ring secured to the body for rotation therewith under the action of the valve operator and a fixed ring rotatably received on a reduced diameter portion of the movable ring and secured against rotation under the action of the valve operator.

Abstract: A pneumatic apparatus to test an engine oil pump of the type designed to be driven by an end of the engine crankshaft. On a test stand, the pump is rotated by a driving mechanism while airflow is generated by the pump itself or while pressurized air is introduced. Air flow characteristics are measured and analyzed to determine acceptability of the pump.

Abstract: A method for testing a valve being driven by an electromagnet having a electromagnet armature, includes determining a value of current in the electromagnet as a response current, at an instant when motion of the electromagnet armature of the valve begins during a switching action of the valve. A force acting through the electromagnet upon the electromagnet armature is determined from the determined response current, at the instant when motion of the electromagnet armature begins, by means of a calibration function, as a response force and as a standard for the condition of the valve. An apparatus for testing a valve being driven by an electromagnetic having a electromagnet armature and an electrical circuit, includes a current meter in the electrical circuit of the electromagnet. A computer is connected to the current meter.

Abstract: A pump includes a quick connect interface that attaches to any drink dispensing to allow the mounting of the pump without the necessity of connection devices such as threaded fittings and/or clamps. The quick connect interface includes a housing having an inlet port and an outlet port. The inlet port connects to a product source to deliver product into the pump, while the outlet port connects the pump to a product dispensing apparatus. Both the inlet and outlet ports include a flow regulator that prevents the flow of product from the quick connect interface when the pump is removed. The housing also has a gas port that connects to a gas source to deliver gas into the pump. The gas port includes a flow regulator that prevents the escape of gas from the gas source when the pump is removed. Additionally, the pump includes a counter that measures the volume of fluid pumped by the pump.

Abstract: A fluid pump for displacing a small, precise volume of fluid for each pump stroke, particularly where the fluid to be displaced is a liquid containing dissolved gas. The precise volume of fluid to be displaced is adjustable to any selected amount up to the full displacement of the pump. The pump has instrumentation that indicates a seal failure within the pump, thus allowing for maintenance on the pump before a total failure. This instrumentation results in increased safety when the pump is used to inject odorant into a natural gas pipeline or in other precision chemical injection applications.

Abstract: Apparatus for determining the position of a piston in a hydraulically or pneumatically operated actuator including a fixed position, rotatable shaft having a pair of attached pins, each pin off-set from the center of the shaft. The pins are positioned on either side of a drive ring located about the circumference of the piston. When the piston moves in either direction, one of the pair of pins will remain in contact with the drive ring and cause uni-directional rotation of the shaft. In order to detect piston position, a sensor is mounted to detect shaft rotation.

Abstract: Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner.

Abstract: A method is disclosed for determining operability of a motor operated valve combination including a valve having a valve stem, a valve disc, a valve seat, and a motor operator having a motor drive interconnecting the motor to the valve stem for movement of the valve disc toward and into engagement with the valve seat to close the valve and a control switch for deactivating the motor. The method comprises the steps of sensing the real motor power of the motor as a function of time during valve closing with zero differential pressure applied to the valve at a first time. From the sensed information, the rate of motor power build-up is determined after the onset of valve wedging during valve closing at the first time. The real motor power of the motor is again sensed as a function of time during valve closing with zero differential pressure applied to the valve at a second time which is subsequent to the first time.

Abstract: A method and apparatus for measuring and monitoring the axial load or thrust on the valve stem of an air operated valve assembly. The top end of the valve stem is connected to bottom end of the valve actuator drive shaft by a marriage block connector member having a plurality of strain gages capable of generating an electrical signal representative of the axial load or thrust on the valve stem. The marriage block connector member is also provided with a gage capable of generating an electrical signal representative of the axial position of the valve stem. The apparatus and methods disclosed are used for valve diagnostic testing from a remote location or for a valve control system.

Abstract: An apparatus and method for detecting a leak in a closed, fluid transfer system, specifically a hydraulic system, by comparing the actual rate of fluid level change in the fluid reservoir to the rate of fluid level change computed from the rate of flow and capacity of the system wherein an actual rate of level change in excess of the computed change indicates leakage from the system. An apparatus for determining direction of flow through a conduit and method using the apparatus in which a magnet on a piston slidably engaged inside a valve body is caused to move thereby causing a variance in a measured inductance indicating the direction the piston has moved.

Abstract: Method of testing the functionality of condensate dischargers. Any ultrasonic vibrations present in the condensate discharger are picked up with an ultrasonic vibration sensor and transformed into an electric output signal. The latter is compared in an evaluation unit with stored data. A test result is then formed based on predetermined decision criteria. The test is carried out over a predetermined test duration, within which instantaneous values of the ultrasonic vibrations are picked up at predetermined times and, if need be, smoothed. The test result is based on the instantaneous values.

Abstract: Disclosed is apparatus and a system for the diagnostic testing of a valve actuator used in an electric motor operated valve that is able to induce a variety of actively controllable and adjustable torsional and axial loads on the valve actuator and while providing measurement of both the torsional and axial forces being produced by the actuator while subject to the induced loads.

Abstract: A mass air flow sensor calibration air flow stand is tested during production by substituting a nozzle supplying a predetermined amount of air flow for a mass air flow sensor in the production line. The calibration air flow stand is supplied air from the nozzle. If the calibration air flow stand is operating properly the flow in the air flow stand is the same as the predetermined amount of air flow.

Abstract: An actuator movement detector (10) indicates proper engagement of a solenoid (12). The current flowing through a field coil (16) is converted to a sense voltage that exponentially increases and then follows a dip before increases again to a steady state value greater than the first peak value. The exponentially increasing sense voltage is stored across a capacitor (24). Any AC variation about the stored sense voltage sets the output state of comparators (30, 32) and determines a first peak value of the sense voltage. After the first peak, a counter (44) must count to a predetermined value during the low peak before the sense voltage returns to its first peak value. If the counter reaches at least the predetermined count value before returning to its first peak value and count back down to zero before reaching steady state, then the solenoid is considered engaged.

Abstract: An apparatus, for testing a spring pack of a valve operator, includes a hollow housing with a coupling for attaching to the valve operator. A slider is received within the housing and moves therein when driven by a bolt that extends through a threaded aperture in the housing. A load sensor is attached to the slider and extends through the coupling and engages a valve operator component that is connected to the spring pack. As a technician turns the bolt, the apparatus compresses the spring pack within the valve operator and the load sensor produces an electrical signal that indicates how much force is exerted by the spring pack. At the same time, a transducer produces another electrical signal indicating the displacement of the spring pack.

Abstract: A motor operated valve monitoring system utilizes two diagnostic couplings with quick disconnect electrical connectors. One coupling is used for monitoring switch actuation on the motor operated valve, and the second is for measuring three phase power to an AC motor on the valve. These couplings are connected in-line with the quick disconnect connectors and allows the user to perform a test without having to remove the limit switch cover from the actuator. These couplings will reduce testing time for conventional valve monitoring systems, and provide for readily mountable sensors for installation of an online valve diagnostic system to an existing valve and valve operator.

Abstract: A method is disclosed for approximating the stem thrust during the operation of a motor operated valve combination including a valve having a valve stem, a valve disk, a valve seat, and a motor operator having a motor drive means interconnecting the motor to the valve stem for movement of the valve stem disk toward and into engagement with the valve seat to close the valve and a control switch for deactivating the motor.

Abstract: A method for approximating a stem thrust difference during the operation of a motor operated valve combination includes the steps of sensing the stem thrust of the motor operated valve combination as a function of time during valve closing at a first time. From the sensed information, the rate of thrust build-up is determined after the onset of wedging during valve closing at the first time. The real electrical power of the motor is then sensed as a function of time during valve closing at a second time which is subsequent to the first time. The rate of real motor power build-up after the onset of wedging during valve closing at the second time is determined from the sensed information. The ratio of thrust change to power change is approximated by dividing the rate of thrust build-up after the onset of wedging at the first time by the rate of real motor power build-up after the onset of wedging at the second time.

Abstract: A method and apparatus for determining the total flow rate of air flowing through a ventilation installation with a free suction fan (15) is described. The flow rate or a corresponding pressure is determined by measurement of the partial flow rate or a corresponding pressure at at least one measurement point in the vicinity of the inlet opening of the fan. A measurement tube (20) open at both ends is suitably used, and oriented with its longitudinal axis in the inflow direction, flow sensors being arranged inside the measurement tube. In this way, there is obtained good measurement accuracy within a large flow range.

Abstract: A data acquisition system (1) by which environmental parameters proximate to plant installed valves (2) may be monitored, recorded and correlated with other valve operating data. The system includes sensors (8) for sensing environmental parameters such as gas/vapor concentration, temperature or humidity. The system also includes sensors for sensing changes in the actuating variable (34) and sensors for sensing valve stem displacement (58). The sensors (8, 34, 6) generate electrical signals proportional to the value of the sensed parameter. First data interface equipment (32, 42, 43) is provided for digitizing the sensed actuating variable as the actuating variable is changed to displace the stem, preferably a full stroke from the open-to-close-to-open positions or vice versa. Second data interface equipment (7, 45) is provided for digitizing the sensed environmental parameter as the stem is displaced. Third data interface equipment (6, 45) is provided for digitizing the sensed stem displacement.

Abstract: A scroll type machine is disclosed which is designed to enable it to be fully assembled prior to being installed in a hermetic shell and incorporates an improved mounting arrangement for the non-orbiting scroll member. This design enables the compressor to be tested without the need to first install it in the outer shell. This feature in combination with the mounting arrangement greatly facilitates manufacturing, assembly, testing, effectively prevents radial displacement of the non-orbiting scroll member, and offers the advantages of axial compliance. In one embodiment, the non-orbiting scroll is axially movably secured to a bearing housing by means of a plurality of bolts or bolts and sleeves. In another embodiment a rigid annular ring serves to axially movably secure the non-orbiting scroll to the bearing housing while in a third embodiment a stamped ring is secured to both the non-orbiting scroll and the bearing housing.

Abstract: A method is disclosed for determining operability of a motor operated valve combination including a valve having a valve stem, a valve disc, a valve seat, and a motor operator having a motor drive interconnecting the motor to the valve stem for movement of the valve disc toward and into engagement with the valve seat to close the valve and a control switch for deactivating the motor. The method comprises the steps of sensing the real motor power of the motor as a function of time during valve closing with zero differential pressure applied to the valve at a first time. From the sensed information, the rate of motor power build-up is determined after the onset of valve wedging during valve closing at the first time. The real motor power of the motor is again sensed as a function of time during valve closing with zero differential pressure applied to the valve at a second time which is subsequent to the first time.

Abstract: The present invention is a sludge pump system which includes a means for monitoring operation of a sludge pump. The sludge pump includes a material cylinder and a piston moveable in the material cylinder. A pump drive moves the piston during working cycles which include a pumping stroke and a filling stroke. A pump valve mechanism connects the material cylinder to an outlet during pumping strokes and connects the material cylinder to an inlet during filling strokes. A means for monitoring operation of the pump is provided. The means for monitoring includes a means for sensing a first parameter related to operation of the pump drive, a means for sensing a second parameter indicative of operation of the piston, and a means for determining errors in the operation of the pump based upon the first parameter and the second parameter.

Abstract: Centrifugal pumps and similar fluid handling machines may be tested to detect leakage from shaft seal assemblies by an apparatus which includes a support flange for supporting a section of the pump casing including the seal assembly. The apparatus includes a housing portion with an interior chamber which may be placed in communication with a source of pressure fluid such as compressed air to act on the seal assembly to detect any fluid leakage therefrom. The apparatus includes a cylindrical support flange and removable adaptor plates which may be interchanged depending on the configuration of the pump casing.

Abstract: A method of verifying that a safety valve, normally biased to a closed position and opened by hydraulic pressure applied thereto by a fluid supplied at a constant flow rate, is operating correctly within an oil well involves comparing reference and operating curves associated with the valve. The reference curve represents the hydraulic pressure over time applied to the safety valve to open the valve when the valve is operating correctly. The operating curve is prepared with the safety valve installed within an oil well and also represents the hydraulic pressure over time applied to the safety valve to open the valve. Any deviation between the reference and operating curves indicates a potential malfunction and, possible, a precise type of malfunction associated with the safety valve.

Abstract: A stack flow rate measurement system and method utilizes the measured temperatures and pressures of the flue gases in a stack and the measured power supplied to a fan to calculate and display flue gas flow rate without direct measurement of gas velocities in the stack.

Abstract: A production functional test for hydraulic brake control and traction control units which utilizes compressed air as a test medium. Compressed air is applied to an external port of a hydraulic brake or traction control unit which includes valves, accumulators and a positive displacement pump driven by an electric motor connected by internal passageways. The air pressure at another external port is monitored while the various components are exercised according to a test sequence. The monitored pressure must be within predetermined limits at various points of the test to demonstrate that the brake control unit is functioning properly. Air flow rates and pump motor current are also measured at specific points in the test. The test method can identify incorrectly sized and installed components.

Abstract: Automatic test equipment for testing hydraulic/pneumatic devices which devices are included within the test system as well as those which may be attached to the test system. Object oriented programming preferably using C++ language is utilized. Abstract classes representative of characteristics of a group of devices to be tested are provided. Also provided are subclasses characteristic of types of units to be tested. Upon declaration of a specific instance of a type of unit to be tested, the abstract class is inherited into a subclass which in turn is incorporated into the unique characteristics for the declared unit to be tested. A test program is activated for the specific unit to be tested. The test program is also constructed by utilizing abstract and subclasses of information characteristic to the unit to be tested.

Abstract: A non-intrusive method for timing the full operational motion of a valve plug (26) in an electrically actuated, pneumatically operated valve (10). An actuation signal is sent to the valve actuator (54). A coil of wire (68) around the valve actuator solenoid (56), an accelerometer (70) on the solenoid slug (64), or a connection to a permanent pressure sensor (72), non-intrusively senses arrival of the actuation signal at the valve. The time measuring equipment (12) begins timing when the actuation signal is sensed. A laser valve motion sensor (74) then non-intrusively senses when the valve plug reaches a limit of motion. The time measuring equipment ends timing when the valve plug reaches a limit of motion. The time measuring equipment then records the elapsed time from the sensing of the arrival of actuation signal to the final limit of motion of the valve plug.

Abstract: A non-intrusive vibration measurement system and method using commercial ultrasonic instruments together with digital signal filtering and analysis techniques is adapted to quantitatively detect vibrations as small as 0.04-inch peak-to-peak. The system and its methodology is used for in-service vibration monitoring of internal components of check valves, pumps, nuclear reactors, steam generators and heat exchangers, especially when the vibration frequency is too low for quantitative analysis by accelerometers and when the strain induced is too low for strain gauge analysis, and when the vibrating component is in an "encased" environment.

Abstract: The invention herein described relates to devices used to test the integrity of fire sprinkler systems. The present device incorporates a control panel which allows a single operator to electrically activate a test valve within a specific sprinkler network. The interval between the initiation of water flow and the resulting alarm signal is timed by the operator using the control panel. The operator can test any of the building's sprinkler networks simply by adjusting a rotary switch located on the control panel. In this manner, the time and expense associated with sprinkler testing may be greatly reduced by having a single operator perform dependable tests of the entire automatic sprinkler system from one location.

Abstract: An assembly including a tray-like member having a multiplicity of parallel adjacent elongate troughs. Each of the troughs has a major portion adjacent a first edge, and a minor portion adjacent a second edge; and the assembly includes a transparent polymeric sheet sealed over the minor portions of the troughs to define receptacles for liquid. After the major portions of the troughs are positioned beneath the spray zone at a specific distance from the nozzles with the troughs extending transverse of the elongate spray zone and after liquid is sprayed through the spray nozzles upon its upper surface, the assembly can be tipped so that the liquid collected in the troughs will run into the receptacles and the comparative resultant levels of liquid the receptacles will provide a visual indication of the uniformity of the amount of liquid being delivered by the nozzles along the spray zone at the specific distance.

Abstract: The axial force on the valve stem of a large valve can be related to the output of a strain sensor mounted on the yoke of the valve, but accuracy can be achieved only if the strain sensor is first calibrated by applying a known axial force to the valve stem. This can be done conveniently by using the invention, which includes two loading beams juxtaposed on opposite sides of the valve stem, elongated in a direction perpendicular to the valve stem, and including a split nut or a collet for gripping the valve stem. Legs extend from the ends of the loading beam assembly parallel to the valve stem, and one or both of these legs includes a hydraulic ram for applying force to one or both ends of the loading beam assembly. This applied force can be measured independently of the yoke-mounted strain sensor.

Abstract: The present invention is a method for determining the mass flow rate of liquid from each of the nozzles on a manifold of nozzles. A method is demonstrated to provide an absolute calibration technique.

Abstract: An apparatus for testing the opening pressure of a relief valve has a clamp removably secured to the bonnet of a relief valve. The clamp has four upstanding bolts slidably held in T-shaped slots. The bolts mount the base plate of a frame which carries a lifting cylinder and transducer. The cylinder connects to the relief valve stem and applies a lifting force thereto. The transducer measures the amount of force needed to open the valve. The frame is removable from the clamp which provides access to the relief valve adjustment nut. Adjustments in the relief valve opening pressure can be made without requiring removal of the clamp. A calibration adaptor fits on the frame to allow testing of the transducer in situ.

Abstract: The checking apparatus for injection- or infusion-type pumps comprises a glass piston syringe, a linear potentiometer whose spindle is rigidly connected to the piston of the glass piston syringe, a pressure transducer in communication with the syringe inlet, and an electronic computing and evaluating means connected through a water-filled tube to the glass piston syringe and presses water into the glass piston syringe at a predetermined delivery rate. The apparatus displays on three display panels. These important parameters can be measured quickly and precisely with the aid of said apparatus.

Abstract: A method and device for testing artificial or natural venous valves. The device comprises (a) a fixture for mounting a sample valve on a liquid flow path, (b) a muscle pump component and/or (o) respiratory pump component and/or (d) capacitance reservoir component and/or (e) vertical hydrostatic column component, all of the components being fluidly connected to the flow path to mimic the muscle pump, respiratory pump, capacitance and hydrostatic impedance effects of actual in situ venous circulation in the mammalian body. The invention includes methods of testing venous valves by mimicking known hemodynamic flow conditions within a mammalian body.

Abstract: A valve test unit (100) for attachment to a value (12) having a fluidly operated stem actuator (20a) responsive to a positioner device (24a). The unit includes a first input port (102) connectable to a source (104) of fluid pressure, a second input port (106) connectable to a source (108) of electrical power, a first output port (110) fluidly connected to the first input port, for delivering a controlled fluid pressure from the unit, and a second output port (114) electrically connected to the second input port, for delivering a controlled electrical signal from the unit. Test programs (118) are provided for converting fluid pressure, at the first input port, into a controlled, time dependent fluid pressure at the first output port and converting electrical power at the second input port into a controlled, time dependent electrical signal at the second output port.