ISO/TC 131/SC 8 - Product testing

This document specifies methods for determining the performance and the efficiency of water-hydraulic positive displacement pumps having continuously rotating shafts. This document provides test equipment, a test procedure under steady-state conditions and the presentation of test results.

This document establishes general principles for the measurement of performance parameters under static or steady-state conditions. This document provides guidance on the sources and magnitudes of uncertainty to be expected in the calibration of and measurements using hydraulic fluid power components. It describes practical requirements for assessing the capability of the measuring system, and hence the level of uncertainty of the measurement system, or for assisting in developing a system which will meet a prescribed level of uncertainty.

This document establishes procedures for measuring the average steady-state pressure in a hydraulic fluid power conduit. It is applicable to the measurement of average steady-state pressure in closed conduits with inside diameters greater than 3 mm, transmitting hydraulic fluid power with average fluid velocities less than 25 m/s and average steady-state static pressures less than 70 MPa. It is not applicable to sensors which are flush mounted with, or an integral part of, the closed fluid conduit wall. It provides the formulae for estimating the total uncertainty in a given pressure measurement.

This document specifies methods for determining the performance and efficiency of hydraulic fluid power positive displacement pumps, motors and integral transmissions. It applies to components having continuously rotating shafts. This document specifies the requirements for test installations, test procedures under steady-state conditions and the presentation of test results.

ISO 10767-1:2015 establishes a test procedure for measuring the source flow ripple and source impedance of positive-displacement hydraulic pumps. It is applicable to all types of positive-displacement pumps operating under steady-state conditions, irrespective of size, provided that the pumping frequency is in the range from 50 Hz to 400Hz. Source flow ripple causes fluid borne vibration (pressure ripple) and then airborne noise from hydraulic systems. This procedure covers a frequency range and pressure range that have been found to cause many circuits to emit airborne noise which presents a major difficulty in design of hydraulic fluid power systems. Once the source flow ripple and source impedance of hydraulic fluid power pump are known, the pressure ripple generated by the pump in the fluid power system can be calculated by computer simulation using the known ripple propagation characteristics of the system components. As such, this part of ISO 10767 allows the design of low noise fluid power systems to be realized by establishing a uniform procedure for measuring and reporting the source flow ripple and the source impedance characteristics of hydraulic fluid power pumps. In ISO 10767-1:2015, calculation is made for blocked acoustic pressure ripple as an example of the pressure ripple. An explanation of the methodology and theoretical basis for this test procedure is given in Annex B. The test procedure is referred to here as the two pressures/two systems method. Ratings are obtained as follows: a) source flow ripple (in the standard "Norton" model) amplitude, in cubic meter per second[m3/s], and phase, in degree, over 10 individual harmonics of pumping frequency; b) source flow ripple (in the modified model) amplitude, in cubic meter per second [m3/s], and phase, in degree, over 10 individual harmonics of pumping frequency; and its time history wave form, c) source impedance amplitude, in Newton second per meter to the power of five [(Ns)/m5]., and phase, in degree, over 10 individual harmonics of pumping frequency; d) blocked acoustic pressure ripple, in MPa (1 MPa = 106 Pa) or in bar (1 bar = 105 Pa), over 10 individual harmonics of pumping frequency; and the RMS average of the pressure ripple harmonic f1 to f10.

ISO 10771-1:2015 specifies a method of fatigue testing the pressure-containing envelopes of components used in hydraulic fluid power systems under sustained steady cyclic internal pressure loads. This part of ISO 10771 is only applicable to component pressure-containing envelopes that - are manufactured from metals, - are operated at temperatures that exclude creep and low-temperature embrittlement, - are only subjected to pressure-induced stresses, - are not subjected to loss of strength due to corrosion or other chemical action, and - might include gaskets, seals, and other non-metallic components; however, these are not considered part of the pressure-containing envelope being tested (see 5.7). ISO 10771-1:2015 does not apply to piping as defined in ISO 4413 (i.e. connectors, hose, tubing, pipe). See ISO 6803 and ISO 6605 for methods of fatigue testing of piping devices. ISO 10771-1:2015 establishes a general test method that is applicable for many hydraulic fluid power components, but additional requirements or more specific methods that can be required for particular components are contained in the annexes or other standards. Test pressure is to be determined by the user. See ISO/TR 10771‑2 for a possible rating method.

ISO/TR 19972-1:2009 provides a means for determining the reliability of hydraulic fluid power components using: estimates from a design analysis; analysis of laboratory testing to failure or suspension; analysis of field data; analysis of a substantiation test. These methods apply to the first failures without repairs, but exclude certain infant mortality failures. Specific component test procedures and exclusions are provided in subsequent parts of ISO/TR 19972. ISO/TR 19972-1:2009 also provides calculation methods, reporting descriptions and examples of reliability calculations.

ISO 15086-3:2008 describes the procedure for the determination of the impedance characteristics of hydraulic components, by means of measurements from pressure transducers mounted in a pipe. ISO 15086-3:2008 is applicable to passive components, irrespective of size, operating under steady-state conditions, over a frequency range from 10 Hz to 3 kHz.

ISO/TR 10771-2:2008 specifies a test method for fatigue rating of the pressure-containing envelopes of components used in hydraulic fluid power systems, as tested under steady internal cyclic pressure loads in accordance with ISO 10771-1.

ISO 8426:2008 specifies the methods of determining the derived capacity of hydraulic fluid power positive displacement pumps and motors under steady-state conditions and at defined, continuous shaft rotational frequencies. Units can be tested as a positive displacement pump, with mechanical energy applied to the shaft and hydraulic energy obtained at the outlet fluid connection, or as a motor, with hydraulic energy supplied to the inlet fluid connection and mechanical energy obtained at the shaft.

ISO 17599:2003 specifies methods for determining the steady-state performance characteristics and dynamic performance characteristics of positive-displacement electrically and electronically controlled hydraulic pumps, so as to allow comparison of the performance of different components. Pumps covered by ISO 17599:2003 have the capacity to affect changes in the output flow or pressure in proportion to the electrical or electronic input signals. These pumps can be of the load-sensing control type, servo-control type, or electrical variable displacement mechanism type, which control output flow and output pressure by feedback using electrical signals.

ISO 16902-1:2003 establishes a test code based on ISO 9614-1 and ISO 9614-2 for determining the sound power levels of a hydraulic fluid power pump under controlled conditions of installation and operation. The sound power level will include sound power radiated by any piping within the measurement surface. ISO 16902-1:2003 is suitable for providing a basis for comparing the airborne noise levels of any type of pump that is normally used to convert rotary mechanical power to hydraulic fluid power, incorporating valves, solenoids, drive gears, couplings or any other auxiliary device normally fitted in service.

This part of ISO 4392 specifies two test methods for determining the startability of rotary hydraulic motors. It describes two comparable methods of measurement, namely the constant torque method and the constant pressure method. Since the results obtained by these two methods are equivalent, no preference is given to either.

This part of ISO 4392 describes a method of determining the low speed characteristics of positive displacement rotary fluid power motors, of either fixed or variable displacement types. The method involves testing at slow speeds which may generate frequencies having a significant influence upon the steady continuous torque output of the motor and affect the system to which the motor would be connected.

Describes a method of determining the low-speed characteristics of positive-displacement rotary fluid power motors under constand flow and constant torque conditions. The method involves testing at slow speeds, which may generate frequencies having a significant influence upon the steady continuous torque output of the motor and affect the system to which the motor would be connected. The accuracy of measurement is divided into three classes, A, B and C, which are explained in annex A.

Establishes a test code describing procedures based on ISO 2204. Applies to all types of fluid power pumps. Guidelines for application are given in annex C. This second edition cancels and replaces the first edition (1979). Annexes C and D are for information only.

Establishes a test code describing procedures based on ISO 2204. Applies to all types of fluid power motors. Guidelines for application are given in annex C. This second edition cancels and replaces the first edition (1984). Annexes C and D are for information only.

This part closely follows the methods described in the two other parts, but allows the use of alternative pump mounting and drive configurations which are simpler and cheaper to implement in an anechoic chamber. May also be applied to test motors.

Specifies methods for testing valves which are used in a circuit in order to determine their steady-state and dynamic performance. Requirements for test installations and procedures, measurements and presentation of results are specified. Does not establish limits of performance. Accuracy of measurement is divided into three classes (A, B and B) which are explained in annex A. Guidance as to the use of practical units for the presentation of results is given in annex B.

ISO 10770-3:2007 describes test methods for determining the performance characteristics of electrically modulated hydraulic pressure control valves.

ISO 4409:2007 specifies methods for determining the performance and efficiency of hydraulic fluid power positive displacement pumps, motors and integral transmissions. It applies to components having continuously rotating shafts. ISO 4409:2007 specifies the requirements for test installations, test procedures under steady-state conditions and the presentation of test results.

ISO 10771 specifies a method of fatigue testing the pressure-containing envelopes of components used in hydraulic fluid power systems under sustained steady cyclic internal pressure loads. ISO 10771 is only applicable to component pressure-containing envelopes that are manufactured from metals, are operated at temperatures that exclude creep and low-temperature embrittlement, are only subjected to pressure-induced stresses, are not subjected to loss of strength due to corrosion or other chemical action and may include gaskets, seals and other non-metallic components; however, these are not considered part of the pressure-containing envelope being tested.

Specifies a precision method for the determination of pressure ripple levels and source impedance generated in hydraulic fluid power systems and components by positive-displacement hydraulic pumps.

Establishes procedures for measuring the average steady-state pressure in a hydraulic fluid power conduit. Applies to the measurement in closed conduits with inside diameters greater than 3 mm, transmitting hydraulic fluid with velocities less than 25 m/s and pressures less than 70 MPa.

Establishes general principles for the measurement of performance parameters under static or steady-state conditions. Describes practical requirements for assessing the capability of the measuring system and hence the level of accuracy of measurement.

Specifies a method for testing components which use gases to enable their flow-characteristics under steady-state conditions to be compared. Specifies also requirements for the test installation, the test procedure, and the presentation of results. Accuracy of measurement is divided into two classes (A and B) which are explained in annex A. General background information is given in annex B, and the basic theoretical equations are given in annex C. Guidance as to the use of practical units for the presentation of results is given in annex D.

This part specifies two test methods for hydraulic motors. Describes two comparable methods of measurement, namely the constant torque method and the constant pressure method. The accuracy of measurements is divided into 3 classes, A, B, and C which are explained in the normative annex A. The normative annex B includes the classes of measurement accuracy, and the normative annex C contains the use of practical units. This second edition cancels and replaces the first edition (1988).

This part describes a method of determining the characteristics of motors, of either fixed or variable displacement types. The accuracy of measurements is divided into 3 classes, A, B, and C which are explained in annex A. Figure 1 shows a typical test circuit for bidirectional motor. The informative annex B contains the bibliography. This second edition cancels and replaces the first edition (1988).

Specifies the methods for determining the derived capacity under steady-state conditions and at defined, continuously rotating shaft speeds. The unit may be tested as a pump, with mechanical energy applied to the shaft and hydraulic energy obtained at the fluid connections, or as a motor, with the hydraulic energy supplied to the fluid connections and mechanical energy obtained at the shaft. Accuracy of measurement is divided into three classes (A, B, and C) which are explained in annex A.

Specifies methods for determining the performance and efficiency of equipment, and applies to components having continuously rotating shafts. Describes requirements for test installations, test procedures, and the presentation of test results. Annex A gives guidance as to the use of practical units, annex B contains information on errors and classes of measurement accuracy, and annex C provides a pretest checklist of those items on which agreement is recommended between the parties concerned.