ISO/TC 131 - Fluid power systems

This document specifies the housing dimensions for class A O-rings for general industrial applications conforming to ISO 3601-1, as well as housing dimensions for class B O-rings used on selected metric-dimensioned hardware, e.g. fluid power cylinder bores and piston rods. These O-rings are for use in general hydraulic and pneumatic applications without and with anti-extrusion rings (back-up rings). The dimensions of the O-rings (d1 and d2), size codes (SC) and tolerances conform to ISO 3601-1. This document also addresses different design approaches in industry, and this is reflected in the table structures for hardware dimensions. Using the O-ring as a starting point to design the optimal hardware dimensions is reflected in REF Table_tab_3 \r \h Tables 3 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000C0000005400610062006C0065005F007400610062005F0033000000 , REF Table_tab_5 \r \h 5 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000C0000005400610062006C0065005F007400610062005F0035000000 , and REF Table_tab_8 \r \h 8 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000C0000005400610062006C0065005F007400610062005F0038000000 . Using fixed hardware dimensions (i.e. bore/rod) and choosing the most appropriate O-ring to fit is reflected in REF Table_tab_4 \r \h Tables 4 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000C0000005400610062006C0065005F007400610062005F0034000000 and REF Table_tab_6 \r \h 6 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000C0000005400610062006C0065005F007400610062005F0036000000 . Housing dimensions for the O-rings intended for aerospace applications that are specified in ISO 3601-1 are addressed in REF Annex_sec_A \r \h Annex A 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000C00000041006E006E00650078005F007300650063005F0041000000 . NOTE 1 It is expected that O-ring housing dimensions for special applications be agreed upon between the O-ring manufacturer and the user. NOTE 2 The term “housing”, in this document, is used to describe the groove or cavity, into which the O-ring is fitted, and the mating surface, which between them confine the O-ring.

This document specifies the two-step Toet method for the determination of the derived displacement of hydraulic fluid power positive displacement pumps and motors under steady-state conditions. A value for the derived displacement is determined from measurements at multiple shaft speeds.

This document specifies the zero-pressure intercept method for the determination of the derived displacement of hydraulic fluid power positive displacement pumps and motors under steady state conditions. A single value for the derived displacement is determined from measurements at a single shaft speed.

This document specifies only geometrical data relating to cavities in which two-port hydraulic slip-in cartridge valves are mounted in order to ensure interchangeability. NOTE For example, this document does not specify rated pressures. It applies to cavities for two-port hydraulic slip-in cartridge valves which are generally applicable to industrial equipment.

This document specifies a procedure for the determination of a rating of the source flow ripple, source impedance and pressure ripple levels generated by positive-displacement hydraulic motors, including bidirectional motors. This document is applicable to all types of positive-displacement motor operating under steady-state conditions, irrespective of size, for frequencies from 50 Hz to 3 500 Hz. It is applicable for the inlet port of positive-displacement motors.

This document specifies a design methodology for hydraulic systems that can be operated with the lowest possible energy consumption while maintaining the intended functionality of the stationary or mobile machinery in which they are installed. This document takes into account the duty cycles of the application. The definition of the duty cycles is not part of this document.

This document describes the procedure for the determination of the speed of sound in a fluid enclosed in a pipe, by measurements from pressure transducers mounted in the pipe. This document is applicable to all types of hydraulic circuit operating under steady state conditions, irrespective of size, for pressure pulsations over a frequency range from 10 Hz to 3 kHz.

This document specifies methods and techniques that are applicable to the monitoring of particulate contamination levels in hydraulic systems that cannot be calibrated in accordance with ISO 11171. It also describes the relative merits of various techniques, so that the correct monitor for a given application can be selected. The techniques described in this document are suitable for monitoring: a) the general cleanliness level in hydraulic systems; b) the progress in flushing operations; c) support equipment and test rigs. This document can also be applicable for other liquids (e.g. lubricants, fuels and process liquids). NOTE Instruments used to monitor particulate contamination that cannot be calibrated according to ISO 11171 are not considered as or claimed to be particle counters, even if they use the same physical principles as particle counters

This document specifies the requirements for flexible thermoplastic polyurethane and polyamide tubing conveying compressed air, in sizes from 3 mm to 16 mm (1/8 inch to 1/2 inch) outside diameter. Polyurethane tubings are dedicated for use in the temperature range from –20 °C to 60 °C, while polyamide tubings are dedicated for use in the temperature range from −20 °C to 80 °C. Working pressure depends on the tube size, the service temperature (see Table 13 and Table 14) and tubing material (see Table 15 and Table 16).

This document specifies test procedures and a method of presenting the results concerning the parameters which define the main characteristics to be included in the literature from suppliers of regulators and filter-regulators conforming to ISO 6953-1. The purpose of this document is to: — facilitate the comparison of pressure regulators and filter-regulators by standardizing test methods and presentation of test data; — assist in the proper application of pressure regulators and filter-regulators in compressed air systems. The tests specified are intended to allow comparison among the different types of regulators and filter-regulators; they are not production tests to be carried out on each pressure regulator or filter-regulator manufactured. ISO 6953-3 can be used as an alternative dynamic test method for flow-rate characteristics using an isothermal tank instead of a flow meter. However, this method measures only the decreasing flow rate part of the hysteresis curve of forward flow and relief flow characteristics. NOTE The tests related to electro-pneumatic pressure control valves are specified in ISO 10094−2.

This document specifies which characteristics of compressed air pressure regulators are required to be included in the literature from the supplier. It also applies to filter-regulators. This document applies to: — manually controlled direct operated types (with relieving mechanisms such as a relieving pressure regulator, or without relieving mechanism), — manually controlled internal pilot operating types (e.g. nozzle flapper), and — pressure-pilot operated types. In addition, it specifies the product marking requirements for pressure regulators and filter-regulators. This document is applicable to compressed air pressure regulators with a rated inlet pressure of up to 2 500 kPa (25 bar) and an outlet adjustment pressure of up to 1 600 kPa (16 bar) and to filter-regulators with rated inlet and outlet pressures of up to 1 600 kPa (16 bar), in which the major contaminants are removed by mechanical means. NOTE The main characteristics to be included in the supplier's literature related to electrically modulated pneumatic continuous pressure control valves are specified in ISO 10094-1.

This specification details a test method for static O-ring seals in elastomeric materials which are subject to pressurized gas media at low temperatures. It gives guidance on the design of test equipment, standard test parameters, and reporting criteria. It does not specify performance criteria that should be agreed upon between supplier and customer. The test procedure may be used to test seals of alternate size and design or using alternative media but such deviations shall be detailed separately on the report form and the results shall not be used to determine the minimum operating temperature of seals of any other configuration than that tested.

This document specifies methods for verifying the rated fatigue life and the rated static burst pressure of the pressure-containing envelope (i.e. the filter housing) of a spin-on hydraulic filter with a disposable filter element and a finite life.

This document defines a test method which enables the determination of the characteristic values of discharge flow rate and thermal losses of gas-loaded accumulators with separators used in fluid power systems.

This document provides common installation instructions for all connectors that have adjustable stud ends and O-ring sealing. Conformance with the requirements of this document will result in a considerable reduction of leaks in hydraulic systems.

This document specifies the interface dimensions and basic performance requirements for two series of hydraulic quick-action couplings. Both series are in widespread use and have similar technological advantages: — Series A is used predominantly in Europe and is preferred worldwide for agricultural and forestry machinery. This document specifies additional requirements for Series A for use in the agricultural machinery applications given in ISO 5675. — Series B is used predominantly in North America and in the chemical industry.

This document shows how to use the normative mathematical formulae and tools of ISO 11171. Examples are used to demonstrate their use for calibrating automatic particle counters (APCs).

This document specifies the interface dimensions for interchangeability and specifies the performance requirements for hydraulic quick-action couplings, flush-face type, for use at pressures of 10 MPa (100 bar) to 31,5 MPa (315 bar), depending upon the coupling size. Couplings in accordance with this document are not designed to connect or disconnect under pressure. Couplings in accordance with this document provide for automatic sealing of the fluid pressure on the upstream side and on the downstream side when the coupling is disconnected.

This document specifies test procedures for measuring the shifting times of electrically or pneumatically operated directional control valves. It is applicable to monostable and bistable pneumatic directional control valves, with 2 or 3 position functions.

This document specifies an automatic particle counting procedure for determining the number and sizes of particles present in hydraulic-fluid bottle samples of clear, homogeneous, single-phase liquids using an automatic particle counter (APC) that works on the light-extinction principle. This document is applicable to the monitoring of: a) the cleanliness level of fluids circulating in hydraulic systems; b) the progress of a flushing operation; c) the cleanliness level of support equipment and test rigs; d) the cleanliness level of packaged stock fluid. NOTE Measurements can be made with particles suspended in the original liquid or in a sample of the liquid diluted with a compatible liquid when APC coincidence error limits are exceeded.

This document specifies: a) A multi-pass filtration performance test under cyclic flow conditions with continuous contaminant injection for hydraulic fluid power filter elements. b) A procedure for determining the contaminant capacity, particulate removal and differential pressure characteristics. c) A test currently applicable to hydraulic fluid power filter elements that exhibit an average filtration ratio greater than or equal to 75 for particle sizes ≤25 µm(c), and a final test system reservoir gravimetric level of less than 200 mg/L. It is necessary to determine by validation the range of flow rates and the lower particle size limit that can be used in test facilities. d) A test using ISO 12103‑1 A3 medium test dust contaminant and a test fluid. This document provides a test procedure that yields reproducible test data for appraising the filtration performance of a hydraulic fluid power filter element without influence of electrostatic charge. This document is applicable to three test conditions: — Base upstream gravimetric level of 3 mg/L; — Base upstream gravimetric level of 10 mg/L; — Base upstream gravimetric level of 15 mg/L.

This document specifies the dimensions, performance requirements and test procedures for heavy-duty (S series) and light-duty (L series) stud ends with threads, and the elastomeric sealing (type E) that is used with them as defined in ISO 228-1. Heavy-duty (S series) stud ends with type E sealing in accordance with this document can be used at working pressures up to 63 MPa (630 bar). Light-duty (L series) stud ends with type E sealing in accordance with this document can be used at working pressures up to 25 MPa (250 bar). The permissible working pressure depends upon size, materials, design, working conditions, application, etc. This document is applicable to connectors detailed in ISO 8434-1, ISO 8434-2 and ISO 8434-6. NOTE The Introduction gives recommendations for ports and stud ends to be used for new designs in hydraulic and pneumatic fluid power applications.

This document specifies the general and dimensional requirements for the design and performance of hose fittings with 24° cone connector ends with O-rings according to ISO 8434‑1. These hose fittings are made of carbon steel and are intended for use with hoses with nominal inside diameters from 5 mm through 38 mm (inclusive). NOTE For hose fittings used in hydraulic and pneumatic braking systems on road vehicles, see ISO 4038, ISO 4039‑1 and ISO 4039‑2. These hose fittings are for use in hydraulic fluid power systems with hoses that meet the requirements of respective hose standards and in general applications with suitable hoses.

This document defines the gravimetric method for determining the contamination level of fluids used in hydraulic fluid power systems. The working instructions provided in this document serve for the gravimetric determination of dirt content of pressure fluids from mineral oil with additives. They are used in hydraulic systems with hydrostatic drive.

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

This document specifies dimensions and performance requirements for ports and stud ends with parallel threads (G series thread) for pneumatic fluid power applications. It specifies reusable, positively retained seals for leak-free connections, for use at pressures from −0,09 MPa (−0,9 bar) up to 1,6 MPa (16 bar). This document is applicable for threaded ports and stud ends specified in new designs in pneumatic fluid power applications. WARNING — Ports and stud ends conforming to this document are not intended to connect with ports and stud ends that conform to ISO 1179 (all parts) or threads that conform to ISO 7-1. As shown in Figure 1, significant differences in thread depth exists between ISO 16030 requirement and ISO 1179-1 (Δ1 and Δ2) that makes ports and stud ends conforming to ISO 7-1 unsuitable.

This document specifies dimensions for metric ports for use with the adjustable and non-adjustable stud ends as described in ISO 6149‑2 and ISO 6149‑3. Ports in accordance with this document can be used at working pressures up to 63 MPa (630 bar[1]) for non-adjustable stud ends and 40 MPa (400 bar) for adjustable stud ends. The permissible working pressure depends upon port size, materials, design, working conditions, application, etc. See ISO 6149‑2 and ISO 6149‑3 for pressure ratings. NOTE The Introduction of this document gives recommendations for ports and stud ends to be used for new designs in hydraulic fluid power applications. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.

This document specifies the mounting dimensions required for interchangeability of accessories for 16 MPa (160 bar) compact cylinders conforming to ISO 6020‑2. The accessories have been designed specifically for use with cylinders manufactured in accordance with ISO 6020‑2, but this does not limit their application[1]. This document covers the following accessories, identified in accordance with ISO 6099: — AP6 — rod eye spherical, female thread (see Figure 1 and Table 1); — AB5 — clevis bracket, spherical eye, in angle (see Figure 2 and Table 2); — AA6-L — pivot pin, spherical bearing, locking plate (see Figure 3 and Table 3); — AL6 — locking plate for pivot pin (see Figure 4 and Table 4); — AP2 — rod clevis, female thread (see Figure 5 and Table 5); — AP4 — rod eye plain, female thread (see Figure 6 and Table 6); — AB2 — eye bracket (see Figure 7 and Table 7); — AB4 — clevis bracket, straight (see Figure 8 and Table 8); — AA4-S — pivot pin, plain (split pins) (see Figure 9 and Table 9); — AA4-R — pivot pin, plain (rings) (see Figure 10 and Table 10); — AT4 — trunnion bracket (see Figure 11 and Table 11). These accessories are used on hydraulic cylinders for mechanically transmitting the cylinder force. The design of these accessories is based on the maximum forces resulting from the specified internal diameters of the cylinders and pressures according to ISO 3320 and ISO 2944. This document only applies to the dimensional criteria of products manufactured in conformity with this document; it does not apply to their functional characteristics. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2

This document specifies the mounting dimensions required for the interchangeability of accessories for 16 MPa (160 bar) medium series cylinders in accordance with ISO 6020‑1 and for 25 MPa (250 bar) series cylinders in accordance with ISO 6022. The accessories have been designed specifically for use with cylinders manufactured in accordance with ISO 6020‑1 and ISO 6022, but this does not limit their application[1]. This document covers the following accessories, identified in accordance with ISO 6099: — AP2 — rod clevis, female thread (see Figure 1 and Table 1); — AF3 — rod flange, circular (see Figure 2 and Table 2); — AB4 — clevis bracket, straight (see Figure 3 and Table 3); — AB3 — clevis bracket, in angle (see Figure 4 and Table 4); — AT4 — trunnion bracket (see Figure 5 and Table 5); — AA4-R — pivot pin, plain bearing (snap ring type) (see Figure 6 and Table 6); — AA4-S — pivot pin, plain bearing (split pin type) (see Figure 7 and Table 7); — AA6-R — pivot pin, spherical bearing (snap ring type) (see Figure 6 and Table 6); — AA6-S — pivot pin, spherical bearing (split pin type) (see Figure 7 and Table 7); — AP6 — rod eye spherical, female thread (see Figure 8 and Table 8); — AP4 — rod eye plain, female thread (see Figure 9 and Table 9). These accessories are used on hydraulic cylinders for mechanically transmitting the cylinder force. The design of these accessories is based on the maximum forces resulting from the specified internal diameters of the cylinders and pressures according to ISO 3320 and ISO 2944. This document applies only to the dimensional criteria of products manufactured in conformity with this document; it does not apply to their functional characteristics. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.

This document specifies procedures for the following: a) primary particle-sizing calibration for particle sizes 1 µm(c) and larger, sensor resolution and counting performance of liquid automatic particle counters that are capable of analysing bottle samples; b) secondary particle-sizing calibration using suspensions verified with a primary calibrated APC; c) establishing acceptable operation and performance limits; d) verifying particle sensor performance using a test dust; e) determining coincidence and flow rate limits. This document is applicable for use with hydraulic fluids, aviation and diesel fuels, engine oil and other petroleum-based fluids. This document is not applicable to particle-sizing calibration using NIST SRM 2806b primary calibration suspensions.

This document describes the following: — a multi-pass filtration performance test with continuous contaminant injection for hydraulic fluid power filter elements; NOTE 1 For the background interlaboratory study used to verify the test methodology, see Annex D. — a procedure for determining the contaminant capacity, particulate removal and differential pressure characteristics; — a test currently applicable to hydraulic fluid power filter elements that exhibit an average filtration ratio greater than or equal to 75 for particle sizes ≥ 25 µm(c), and a final reservoir gravimetric level of less than 200 mg/L; NOTE 2 It is necessary to determine by validation the range of flow rates and the lower particle size limit that can be used in test facilities. — a test using ISO medium test dust (ISO MTD) contaminant and a test fluid in accordance with Annex A. This document is intended to provide a test procedure that yields reproducible test data for appraising the filtration performance of a hydraulic fluid power filter element without influence of electrostatic charge. This document applies to three test conditions: — test condition 1, with a base upstream gravimetric level of 3 mg/L; — test condition 2, with a base upstream gravimetric level of 10 mg/L; — test condition 3, with a base upstream gravimetric level of 15 mg/L.

This document specifies the test procedures and a method of presenting results concerning the parameters which define the main characteristics to be included in the supplier's literature of the electro-pneumatic continuous pressure control valves, conforming to ISO 10094-1. The purpose of this document is: — to facilitate comparison by standardizing the test methods and the presentation of the test results, and — to assist in the proper application of these components in compressed air systems. The specified tests are intended to allow comparison between the different types of continuous pressure control valves; these are not production tests to be carried out on each manufactured product. The tests described in this document are for components with an exhaust port vented to the atmosphere. NOTE 1 The tests related to non-electrically modulated pneumatic continuous pressure control valves are specified in ISO 6953-2. NOTE 2 The tests related to electro-pneumatic continuous flow control valves are specified in ISO 10041-2. NOTE 3 ISO 6953-3 provides an alternate dynamic test method for flow-rate characteristics using an isothermal tank instead of a flow meter. However, this method measures only the decreasing flow rate part of the hysteresis curve of the forward flow and relief flow characteristics.

This document specifies which characteristics of electro-pneumatic continuous pressure control valves are to be included in the supplier's literature. In accordance with ISO 5598, these control valves include: — electrically modulated pneumatic proportional pressure valves, — proportional pressure control valves without electronic pressure feedback, and — proportional pressure control valves with electronic pressure feedback. This document is limited to the characterization of components with an exhaust port to the atmosphere. NOTE 1 The characteristics of non-electrically modulated pneumatic pressure control valves are specified in ISO 6953‑1. NOTE 2 The characteristics of electro-pneumatic continuous flow control valves are specified in ISO 10041‑1.

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 specifies the general and dimensional requirements for the design and performance of flange hose fittings, made of carbon steel, for nominal hose inside diameters of 12,5 mm to 76 mm inclusive, in accordance with ISO 4397, for use with ports and clamps in accordance with ISO 6162‑1 and ISO 6162‑2. Note 1 Materials other than carbon steel can be supplied as agreed between the manufacturer and user. Note 2 For hose fittings used in hydraulic and pneumatic braking systems on road vehicles (as defined in the scope of ISO/TC 22/SC 2, Road vehicles), see ISO 4038, ISO 4039‑1 and ISO 4039‑2. These hose fittings are for use in hydraulic fluid power systems with a hose that meets the requirements of the respective hose standards and in general applications with suitable hoses.

This document specifies a method for the evaluation of the buckling load which: a) takes into account a geometric model of the hydraulic cylinder, meaning it does not treat the hydraulic cylinder as an equivalent column, b) can be used for all types of cylinder mounting and rod end connection specified in Table 2, c) includes a factor of safety, k, to be set by the person performing the calculations and reported with the results of the calculations, d) takes into account possible off-axis loading, e) takes into account the weight of the hydraulic cylinder, meaning it does not neglect all transverse loads applied on the hydraulic cylinder, f) can be implemented as a simple computer program, and g) considers the cylinder fully extended. The method specified is based on the elastic buckling theory and is applicable to single and double acting cylinders that conform to ISO 6020 (all parts), ISO 6022 and ISO 10762. If necessary, finite element analyses can be used to verify as well as to determine the buckling load. The method is not developed for thin-walled cylinders, double-rods or plunger cylinders. The method is not developed for internal (rod) buckling. The friction of spherical bearings is not taken into account. NOTE This method is based mainly on original work by Fred Hoblit[2]. This method has been established in reference to the standard NFPA/T3.6.37[1].

This document specifies dimensions and tolerances of housings for wiper-rings used in reciprocating rod applications for fluid power cylinders. The range of rod diameters is from 4 mm to 450 mm.

This document establishes methods for: — validating equipment used to prepare secondary calibration suspensions for automatic particle counters; — performing online secondary calibration of automatic particle counters; — matching two or more online particle counters, i.e. to count the same number of particles at a given size by two APCs associated online; — validating online particle counting systems with and without online dilution as used, for example, to measure the filtration efficiency of a hydraulic filter as described in the multi-pass filter test in ISO 16889.

This document specifies uniform methods for the testing and performance evaluation of metallic tube connections, stud ends for ports and flange connections for use in hydraulic fluid power applications. This document does not apply to the testing of hydraulic quick-action couplings, which is covered by ISO 18869. Tests outlined in this document are independent of each other and document the method to follow for each test. See the appropriate component International Standard for indications of which tests to conduct and for performance criteria. For qualification of the connector, the minimum number of samples specified in this document is tested, unless otherwise specified in the relevant connector standard or as agreed upon by the manufacturer and the user.

This document specifies the dimensions and associated tolerances for a series of hydraulic cylinder rod seal housings to accommodate elastomer-energized, plastic-faced seals used in reciprocating applications. This document does not stipulate details of seal design, since the manner of construction of seals varies with each manufacturer. The design and material of the seals, and any incorporated anti-extrusion components, are determined by conditions such as temperature and pressure. This document only applies to the dimensional characteristics of products manufactured in accordance with this document. It does not apply to their functional characteristics.

This document specifies the dimensions and associated tolerances for a series of hydraulic cylinder piston seal housings to accommodate elastomer-energized, plastic-faced seals used in reciprocating applications. This document does not stipulate details of seal design, since the manner of construction of seals varies with each manufacturer. The design and material of the seals, and any associated anti-extrusion components, are determined by conditions such as temperature and pressure. This document only applies to the dimensional characteristics of products manufactured in accordance with this document. It does not apply to their functional characteristics.

This document describes a recommended method for the interpolation of particle concentration and filter Beta Ratio data when results are not otherwise available at the desired particle sizes. It is applicable for assessing conformance with existing fluid cleanliness and filter Beta Ratio specifications whereby the specification and actual test results are provided in different units of particle size, for example, the specification is in µm(c), but the particle counts or Beta Ratio data are in units of µm(b). This document is also applicable when particle sizes in specifications and available data use the same units of particle size, but do not correspond to exactly the same sizes, for example, when particle counts at 20 µm(c) are specified, but data was collected at 21 µm(c). This method allows interpolation to intermediate particle sizes within the range of existing data and does not permit extrapolation to particle sizes outside the range of available data.

This document provides the background for ISO 11171:2020 and the use of µm(c) as the sole means of reporting particle size for APC particle count data. It also summarizes results of the international inter-laboratory study (ILS) of its reproducibility using SRM 2806d candidate material and suspensions of Reference Material (RM) 8632a. The ILS results provided the basis for certification of SRM 2806d used for primary calibration of APC. Their implications with respect to particle counting and filter testing are discussed in this document.

This document specifies the code to be used in defining the quantity of solid particles in the fluid used in a given hydraulic fluid power system.

This document specifies sizes and nominal working pressures for seamless and welded precision steel tubes with outside diameters in accordance with ISO 4397, and wall thicknesses and mechanical properties in accordance with ISO 3305. The nominal working pressures included in this document reflect a design factor ratio of 4 to 1 applied to the calculated burst pressures.

This document specifies acceptance and function tests for hydraulic fluid power cylinders.

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.