1、BRITISH STANDARD BS ISO 11425:1996 Implementation of ISO 11425:1996 Rubber hoses and hose assemblies for power-steering systems Specification ICS 43.040.50; 83.140.40BS ISO 11425:1996 This British Standard, having been prepared under the directionof the Sector Board forMaterials and Chemicals, waspu
2、blished under the authorityof the Standards Boardand comes into effect on 15January 1997 BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference PRI/66 Draft for comment 94/303786 DC ISBN 0 580 26816 0 Committees responsible for this British Standard The pre
3、paration of this British Standard was entrusted to Technical Committee PRI/66, Rubber and plastics tubing, hoses and hose assemblies, upon which the following bodies were represented: Association of Metropolitan Authorities British Coal Corporation British Compressed Gases Association British Rubber
4、 Manufacturers Association Ltd. Chief and Assistant Chief Fire Officers Association Energy Industries Council Fire Extinguishing Trades Association Home Office London Fire and Civil Defence Authority Ministry of Defence RAPRA Technology Ltd. Society of Motor Manufacturers and Traders Limited The fol
5、lowing body was also represented in the drafting of the standard, through subcommittees and panels: British Fluid Power Association Amendments issued since publication Amd. No. Date CommentsBS ISO 11425:1996 BSI 11-1998 i Contents Page Committees responsible Inside front cover National foreword ii F
6、oreword iv Text of BS ISO 11425 1BS ISO 11425:1996 ii BSI 11-1998 National foreword This British Standard reproduces verbatim ISO 11425:1996 and implements it as the UK national standard. It supersedes BS 6784:1986 which is withdrawn. This British Standard is published under the direction of the Sec
7、tor Board for Materials and Chemicals whose Technical Committee PRI/66 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related interna
8、tional and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. A British Standard does not purport to include all the necessary provisions of a
9、contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi and ii, theISO title page, pages ii
10、to iv, pages1 to 5 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS ISO11425:1996 ii BSI 11-1998 Contents Page Foreword iv 1 Scope 1 2 Normative references 1 3 De
11、finitions 1 4 Types of hose 1 5 Construction and materials 1 6 Dimensions and tolerances 2 7 Performance requirements 2 7.1 Impulse resistance 2 7.2 Burst pressure requirement 2 7.3 Change in length 2 7.4 Low-temperature flexibility 2 7.5 Adhesion 3 7.6 Ozone resistance 3 7.7 Volumetric expansion 3
12、7.8 Contamination 3 7.9 Corrosion of end fittings 3 7.10 Proof pressure requirement 3 7.11 Cold-start requirement 3 7.11.1 Requirement 3 7.11.2 Test method 3 7.12 Low-pressure burst pressure requirement 3 8 Marking 3 Annex A (normative) Method of test for volumetric expansion A.1 Principle 4 A.2 App
13、aratus 4 A.2.1 Means of increasing hydraulic pressure 4 A.2.2 Calibrated pressute gauge 4 A.2.3 Two valves 4 A.2.4 Laboratory measuring cylinders 4 A.2.5 Short length of 0.5 m bore stainless steel capillary tube 4 A.3 Test fluid 4 A.4 Test piece 4 A.5 Procedure 4 A.6 Expression of results 4 A.7 Test
14、 report 4 Annex B (normative) Method of test for contamination B.1 Principle 4 B.2 Reagent 4 B.2.1 Petroleum ether 4 B.3 Apparatus 4 B.3.1 Glass funnel 4 B.3.2 Beaker 4 B.3.3 Ventilated drying oven 5 B.3.4 Balance 5 B.3.5 Sintered-glass filter 5 B.3.6 Microscope 5 B.4 Procedure 5 B.5 Expression of r
15、esults 5 B.6 Test report 5BS ISO11425-1996 BSI 11-1998 iii Page Annex C (informative) Typical outside-diameter ranges Table 1 Nominal bore 2 Table 2 Hydrostatic-pressure requirements 2 Table 3 Volumetric expansion 3 Table C.1 Typical outside-diameter ranges 5BS ISO 11425:1996 iv BSI 11-1998 Foreword
16、 ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical
17、 committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of elec
18、trotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75% of the member bodies casting a vote. International Standard ISO 11425 was prepare
19、d by Technical Committee ISO/TC45, Rubber and rubber products, Subcommittee SC 1, Hoses (rubber and plastics). Annexes A and B form an integral part of this International Standard. Annex C is for information only.BS ISO 11425:1996 BSI 11-1998 1 1 Scope This International Standard specifies requireme
20、nts for five types of hose and hose assembly used in automobile power-steering systems, the five types differing in their pressure ratings and volumetric expansion. They are for use with fluids in the temperature range 40 C to + 135 C. This International Standard is based on performance tests and, i
21、n order to take account of technological developments, no requirements are included for specific materials, detailed construction or manufacturing methods. WARNING Attention is drawn to the need to ensure that appropriate precautions are taken to ensure the safety of personnel carrying out the metho
22、ds of test specified in this International Standard. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject
23、 to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1402:1994, Rubbe
24、r and plastics hoses and hose assemblies Hydrostatic testing. ISO 2719:1988, Petroleum products and lubricants Determination of flash point Pensky-Martens closed cup method. ISO 2909:1981, Petroleum products Calculation of viscosity index from kinematic viscosity. ISO 2977: 1) , Petroleum products a
25、nd hydrocarbon solvents Determination of aniline point and mixed aniline point. ISO 3016:1994, Petroleum products Determination of pour point. ISO 3819:1985, Laboratory glassware Beakers. ISO 4671:1984, Rubber and plastics hose and hose assemblies Methods of measurement of dimensions. ISO 4672: 2) ,
26、 Rubber and plastics hoses Subambient-temperature flexibility tests. ISO 4788:1980, Laboratory glassware Graduated measuring cylinders. ISO 4793:1980, Laboratory sintered (fritted) filters Porosity grading, classification and designation. ISO 6803:1994, Rubber or plastics hoses and hose assemblies H
27、ydraulic-pressure impulse test without flexing. ISO 7326:1991, Rubber and plastics hoses Assessment of ozone resistance under static conditions. ISO 8033:1991, Rubber and plastics hose Determination of adhesion between components. ISO 9227:1990, Corrosion tests in artificial atmospheres Salt spray t
28、ests. ISO/TR 11340:1994, Rubber and rubber products Hydraulic hose assemblies External leakage classification for hydraulic systems. 3 Definition For the purposes of this International Standard, the following definition applies. 3.1 hose assembly a hose with either permanent or re-usable end fitting
29、s attached 4 Types of hose Hoses shall be one of the following five types: Type 1: low-pressure hydraulic fluid return hoses and hose assemblies Type 2: medium-pressure low volumetric expansion hoses and hose assemblies Type 3: medium-pressure medium volumetric expansion hoses and hose assemblies Ty
30、pe 4: medium-pressure high volumetric expansion hoses and hose assemblies Type 5: high-pressure low volumetric expansion hoses and hose assemblies 5 Construction and materials The hose shall consist of a) a rubber lining; b) a reinforcement; c) a rubber cover or alternatively, for type 5 only, a tex
31、tile cover. The hose shall be uniform in quality and free from porosity, air holes and foreign inclusions. 1) To be published. (Revision of ISO 2977:1989) 2) To be published. (Revision of ISO 4672:1988)BS ISO 11425:1996 2 BSI 11-1998 6 Dimensions and tolerances 6.1 The hose shall have a nominal bore
32、 in accordance with the requirements of Table 1. When determined in accordance with ISO4671, the actual bore shall be within 0,4mm of the nominal bore. Table 1 Nominal bore 6.2 The concentricity based on a total indicator reading between the bore and the outside surface of the cover, determined in a
33、ccordance with ISO4671, shall be not more than 0,75mm. NOTE 1Typical ranges of outside diameters available are given in annexC. 7 Performance requirements 7.1 Impulse resistance When subjected to a pulse test carried out in accordance with ISO6803, using the following conditions, each of at least fo
34、ur test pieces shall withstand a minimum of 225000cycles with no more than ISO/TR11340 class3 leakage at fittings, and no rupture or ballooning of the hose. Test fluid temperature: 135C 2 C Ambient temperature during test: 100C 5 C Cycle rate: 30 to 40 per min Cycle data: Pressure rise time: 0,20s 0
35、,10s Pressure dwell time: 0,65s 0,20s Pressure drop time: 0,20s 0,10s Test pressure: Design working pressure as given inTable 2. 7.2 Burst pressure requirement When tested in accordance with ISO1402, the hose or hose assembly shall withstand the minimum burst pressure given inTable 2. 7.3 Change in
36、length Hoses of types 1, 3 and 4 shall not change in length by more than + 0 % and 8 % and hoses of types 2 and 5 shall not change in length by more than + 2 % and 4 % at the appropriate design working pressure given in Table 2. 7.4 Low-temperature flexibility After conditioning at a temperature of
37、40C 2 C for a period of 72 h, bend a test piece around a mandrel having a diameter eight times the nominal outside diameter of the hose, using the method without torque measurements described in ISO4672. The test piece shall not fracture and the cover shall not show any cracks or breaks. After this
38、test, the test piece shall be allowed to attain ambient temperature and shall then withstand the appropriate proof pressure given inTable 2, using the method described in ISO1402, without any sign of leakage or other defect. Following the proof pressure test, the test piece shall be sectioned and th
39、e lining shall show no evidence of cracking upon visual examination. Table 2 Hydrostatic-pressure requirements Dimensions in millimetres Type 1 Type 2 Type 3 Type 4 Type 5 6,3 9,5 9,5 9,5 9,5 9,5 12,7 12,7 Type Nominal bore Design working pressure Proof pressure Minimum burst pressure mm MPa MPa MPa
40、 1 9,5 1,75 3,5 7,0 2 6,3 9,0 18,0 36,0 9,5 8,0 16,0 32,0 12,7 7,0 14,0 28,0 3 9,5 10,0 20,0 40,0 4 9,5 9,0 18,0 36,0 5 9,5 15,5 31,0 62,0 12,7 14,0 28,0 56,0 NOTEAll pressure values specified are gauge pressures.BS ISO 11425:1996 BSI 11-1998 3 7.5 Adhesion When determined in accordance with ISO8033
41、, for type1, 2, 3 and 4 hoses, and for type5 hoses supplied with a rubber cover, the adhesion between lining and reinforcement, between layers of reinforcement and between reinforcement and cover shall not be less than 1,5 kN/m. 7.6 Ozone resistance When tested in accordance with ISO 7326:1991, meth
42、od1, the test piece shall show no sign of cracking. 7.7 Volumetric expansion This requirement applies to type3 and4 hoses only. When tested by the method described in annexA, the hose or hose assembly shall comply with the requirements ofTable 3. Table 3 Volumetric expansion 7.8 Contamination When d
43、etermined by the method described in annexB, the total amount of impurities shall not exceed 100 mg/m 2and the maximum particle size shall be 70 m. 7.9 Corrosion of end fittings When tested in accordance with ISO 9227 for 168 h, the hose assembly and fittings shall show no evidence of corrosion of t
44、he base metal. 7.10 Proof pressure requirement Each length of hose or each hose assembly subjected to the appropriate proof pressure given in Table 2, using the method described in ISO 1402, for a period of 1min, shall show no sign of rupture or leakage. 7.11 Cold-start requirement (type approval te
45、st for type 4 hose assemblies only) 7.11.1 Requirement When tested in accordance with 7.11.2, the assembly shall show no signs of cracks or leakage at the end of 15 cycles. 7.11.2 Test method 7.11.2.1 Bend the hose assembly into a U shape, fill with test fluid (see A.3) and lower the temperature to
46、40 C 2 C. 3) 7.11.2.2 Apply a pressure pulse of 11 MPa for 1,5 s, twenty times. 7.11.2.3 Allow the assembly to warm up to ambient laboratory temperature and leave for 2 h. 7.11.2.4 Apply a pressure pulse of 11 MPa for 1,5 s, twenty times. 7.11.2.5 Repeat the procedure described in 7.11.2.1 to7.11.2.
47、4 (starting at “lower the temperature to 40C 2 C”) a further fourteen times. 7.11.2.6 Examine the hose assembly visually for signs of cracks or leakage, ignoring any leakage associated with the couplings. 7.12 Low-pressure burst pressure requirement (type 4 hose assemblies only) Fill the hose assemb
48、ly with test fluid (see A.3) and maintain at 40 C 2 C 3)for 12 h. The hose assembly shall then withstand a minimum burst pressure of 36 MPa applied in accordance with ISO1402. 8 Marking Each length of hose shall be legibly and indelibly marked at intervals of no more than 250 mm with the following i
49、nformation: a) the manufacturers name or identification; b) the number of this International Standard and the hose type number; c) the nominal bore of the hose, in millimetres; d) the date of manufacture (at least month and year); e) the design working pressure, in megapascals. EXAMPLE: MAN ISO 11425/3 9,5 10/95 15,5 Hose type Volumetric expansion at 9 MPa 3 10 cm 3 /m to 26 cm 3 /m 4 26 cm 3 /m to 55 cm 3 /m 3) A temperature of 40C may be obtained by us
