1、BRITISH STANDARD BS ISO 7425-1:1988 Hydraulic fluid power Housing for elastomer-energized, plastic-faced seals Dimensions and tolerances Part 1: Piston seal housings ICS 23.100.99 BS ISO 7425-1:1988 This British Standard, having been prepared under the direction of the Engineering Sector Policy and
2、Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 28 August 2002 BSI 28 August 2002 ISBN 0 580 40301 7 National foreword This British Standard reproduces verbatim ISO 7425-1:1988 and implements it as the UK national standard. Together with BS ISO
3、 7425-2:1989 it supersedes BS 6984:1988 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee MCE/11, Fluid seals and housings, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretar
4、y. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of Briti
5、sh Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present
6、 to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an ins
7、ide front cover, the ISO title page, pages ii and iii, a blank page, pages 1 to 5, the National Annex NA page, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comme
8、ntsINTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXjJYHAPOAHAfl OPI-AHM3AMR fl0 CTAHAPTM3AMM Hydraulic fluid power - Housings for elastomer- energized, plastic-faced Seals - Dimensions and tolerantes - Part 1 I Piston seal housing
9、s Transmissions hydrauliques - Logements pour joints en however, consul- tation with the manufacturer is recommended when making the appropriate selection. The requirements for the surface finish of the components in contact with the seal are dependent on the application and its life requirement and
10、 should be subject to agreement between the purchaser and seal manufacturer. 9 Lead-in chamfer 6 Dimensions and tolerantes Seal housing dimensions and tolerantes shall be selected from table 2. 9.1 To protect the seal from darnage during assembly, lead-in chamfers are required, either as an integral
11、 patt of housing components or on separate assembly tools. 7 Extrusion gap 9.2 Reference shall be made to figure 1 for typical location of lead-in chamfers when these are part of the housing compo- nent. The extrusion gap (D - d3; see figure 1) is determined by the bore diameter and adjacent metal c
12、omponents on either side of the Seal. 9.3 The minimum axial length of lead-in chamfers, whether on housing components or assembly tools, is given in table 1. Table 1 - Lead-in chamfer Dimensions in millimetres Radial depth of seal housing, S nom. Minimum axial length of lead-in chamfer, C 5 7,5 10 1
13、2,25 2,5 3,75 15 20 5,5 7,75 IO,5 12,5 1,5 2 2,5 4 5 65 7,5 10 Figure 1 - Example of Piston seal housing 2 BSISO74251:1988OSI 1-5247 8891: IE( Table 2 - Dimensions and tolerantes of seal housings Dimensions in millimetres Bore diameter) Radial depth D s H92) , nom. Groove diameter Axial length d 4 L
14、2 (without back-up rings) (with back-up rings) h92) + 0,2 +0,2 0 0 2,5 11 16 22 3,75 8,5 3,2 20 23 15 22 - 3,75 12,5 3,2 3,75 175 3,2 25 5,5 14 4,2 5 15 5 8 3,75 24,5 3,2 - 32 5,5 21 4,2 I 5 I 22 I 5 I 8 0,5 40 3,75 32,5 3,2 - 5,5 29 4,2 I 5 I 30 I 5 l 8 5,5 39 4,2 - 50 7,75 34,5 6,3 7,5 35 715 12,5
15、 5,5 52 4,2 - 63 7,75 47,5 6,3 7,5 48 7,5 12,5 r max. 515 69 4,2 - 80 7,75 64,5 6,3 10 60 10 16 - 5,5 89 4,2 - 100 7,75 8415 613 10 80 10 16 7,75 109,5 613 - 125 IO,5 104 8,1 10 105 10 16 7,75 144,5 613 - 160 IO,5 139 Kl 12,5 135 12,5 20 7,75 184,5 63 - 200 IO,5 179 8,1 12,5 175 12,5 20 IO,5 229 81
16、- 250 12,25 225,5 kl 15 220 15 25 IO,5 299 811 - 320 12,25 295,5 8,1 15 290 15 25 12,25 375,5 8,1 - 15 370 12,5 20 360 20 32 12,25 475,5 8,1 - 500 15 470 12,5 20 460 20 32 03 1) Bore diameters in accordance with ISO 3320. 2) See ISO 286-2. BSISO74251:1988OSI 45247 : 8891 IE( 10 Identification Statem
17、ent (Reference to this part of ISO 7425) “Piston seal housing for elastomer-energized, plastic-faced Seals selected in accordance with ISO 7425-1, Hydraulic fluid power - Housings for elastomer-energized, plastic- faced Seals Use the following statement in test reports, catalogues and sales Iiteratu
18、re when electing to comply with this part of ISO 7425: - Dimensions and tolerantes - Part 1: Piston sealhousings.” BSISO74251:1988OSI 1-5247 8891: IE( Annex A (informative) Bibliography ISO 468 : 1982, Surface roughness - Parameters, their values and general rules for specifying reguirements. ISO 43
19、94-1 : 1980, Fluid power Systems and components - Cylinder barrels - Part 7: Requirements for steel tubes with specia/y finished bores. BSISO74251:19881) BS 1134-1:1998 Assessment of surface texture Part 1: Methods and instrumentation 2) BS 5242-1:1987 Tubes for fluid power cylinder barrels Part 1:
20、Specification for steel tubes with specially finished surfaces 3)BS 5242-2:1983, ISO 6537:1982 Tubes for fluid power cylinder barrels Part 2: Specification for non-ferrous metallic tubes with specially finished bores National Annex NA (informative) Recommendations for surface texture NA.1 The surfac
21、e texture of components which are in sliding contact with the seal should be 0.1 m to 0.4 m Ra and 1.6 m Rz max., when measured in accordance with BS 1134-1 1) . NA.2 The surface texture of components which are in static contact with the seal should be 0.4 m to 1.6 m Ra and 6.3 m Rz max., when measu
22、red in accordance with BS 1134-1. NOTE Exceptional service conditions may necessitate the selection of other grades of surface texture; reference should be made to BS 5242-1 2)for steel and BS 5242-2 3) for non-ferrous tubes. BSISO74251:1988sihT egap yllanoitnetni tfel knalb BS ISO 7425-1:1988 BSI 3
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