1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS 7993:2011Twin ferrule connectors andassociated tubing for 316stainless steel systems Specification and testmethodsPublishing and copyright informationThe BSI copyright notice
2、displayed in this document indicates when the documentwas last issued. BSI 2011ISBN 978 0 580 54781 2ICS 23.100.40The following BSI references relate to the work on this standard:Committee reference MCE/18/-/4Draft for comment 11/30124825 DCPublication historyFirst published July 2011Amendments issu
3、ed since publicationDate Text affectedBS 7993:2011 BRITISH STANDARDContentsForeword iiiIntroduction 11 Scope 12 Normative references 23 Terms and definitions 34 Design 55 Requirements for construction and materials 316 Pressure/temperature requirements 327 Requirements for tubes 338 Requirements for
4、 screw threads 389 Performance requirements 3810 Marking 4011 Documentation 42AnnexesAnnex A (normative) Test procedures 43Bibliography 54List of figuresFigure 1 Cross-section of a typical twin ferrule connector 5Figure 2 Cross-section of a metric tube end 7Figure 3 Cross-section of a fractional tub
5、e end 9Figure 4 Compression end nut 11Figure 5 Union connector 13Figure 6 Male bulkhead connector 15Figure 7 Equal elbow 16Figure 8 Equal tee 18Figure 9 Equal cross 20Figure 10 Male stud connector (NPT) 21Figure 11 Male stud connector (BSPT) 24Figure 12 Male stud connector (BSPP) 27Figure 13 Bulkhea
6、d connector 28Figure 14 Assembly instructions regarding intermixing and interchanging 42Figure A.1 Test assembly for pressure tests 45Figure A.2 Test assembly for dismantling and reassembly test 45Figure A.3 Salt spray test 46Figure A.4 Hydraulic impulse and vibration rig Plan view 49Figure A.5 Hydr
7、aulic impulse test cycle 49Figure A.6 Geometry of hydraulic impulse and vibration test Side elevationshowing simple cantilever 50Figure A.7 Thermal cycle test assembly 51List of tablesTable 1 Requirements for tube ends for tubes with metric outside diametersizes 8Table 2 Requirements for tube ends f
8、or tubes with imperial outside diametersizes 10Table 3 Requirements for compression end nuts for tubes with metric outsidediameter sizes 12Table 4 Requirements for compression end nuts for tubes with imperial outsidediameter sizes 13Table 5 Requirements for union connectors for tubes with metric out
9、sidediameter sizes 14BRITISH STANDARD BS 7993:2011 BSI 2011 iTable 6 Requirements for union connectors for tubes with imperial outsidediameter sizes 14Table 7 Requirements for male bulkhead connectors for tubes with metricoutside diameter sizes 15Table 8 Requirements for male bulkhead connectors for
10、 tubes with imperialoutside diameter sizes 16Table 9 Requirements for equal elbows for tubes with metric outside diametersizes 17Table 10 Requirements for equal elbows for tubes with imperial outsidediameter sizes 17Table 11 Requirements for equal tees for tubes with metric outside diametersizes 19T
11、able 12 Requirements for equal tees for tubes with imperial outside diametersizes 19Table 13 Requirements for equal crosses for tubes with metric outsidediameter sizes 20Table 14 Requirements for equal crosses for tubes with imperial outsidediameter sizes 21Table 15 Requirements for male stud connec
12、tors (NPT) for tubes with metricoutside diameter sizes 22Table 16 Requirements for male stud connectors (NPT) for tubes with imperialoutside diameter sizes 23Table 17 Requirements for male stud connectors (BSPT) for tubes with metricoutside diameter sizes 25Table 18 Requirements for male stud connec
13、tors (BSPT) for tubes with imperialoutside diameter sizes 26Table 19 Requirements for male stud connectors (BSPP) for tubes with metricoutside diameter sizes 27Table 20 Requirements for male stud connectors (BSPP) for tubes with imperialoutside diameter sizes 28Table 21 Requirements for bulkhead con
14、nectors for tubes with metric outsidediameter sizes 29Table 22 Requirements for bulkhead connectors for tubes with imperialoutside diameter sizes 30Table 23 Working pressure rating for metric size stainless steel tube (bar) 34Table 24 Working pressure rating for metric size stainless steel tube (psi
15、) 35Table 25 Working pressure rating for imperial size stainless steel tube (bar) 36Table 26 Working pressure rating for imperial size stainless steel tube (psi) 37Table 27 Factors used to determine tube pressure ratings at elevatedtemperatures 38Table 29 Letter symbols for connectors 41Table A.1 Te
16、st fluid properties 45Table A.2 Range of tube diameters deemed to passed the fire test 52Table A.3 Results of corrosion resistance test 52Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv,pages 1 to 54, an inside back cover and a back cover.BRITISH STANDARDB
17、S 7993:2011ii BSI 2011ForewordPublishing informationThis British Standard is published by BSI and came into effect on 31 July 2011. Itwas prepared by Panel MCE/18/-/4, Connectors and associated components,under the authority of Technical Committee MCE/18, Fluid power systems andcomponents. A list of
18、 organizations represented on these committees can beobtained on request to their secretary.Information about this documentProduct certification/inspection/testing. Users of this British Standard are advisedto consider the desirability of third-party certification/inspection/witness oftesting of pro
19、duct conformity with this British Standard. Users seeking assistancein identifying appropriate conformity assessment bodies or schemes may ask BSIto forward their enquiries to the relevant association.Users of this standard are also advised to consider the desirability of requestingconformity to BS
20、EN ISO/IEC 17025 and BS EN 45011.Assessed capability. Users of this British Standard are advised to consider thedesirability of quality system assessment and registration against the appropriatestandard in the BS EN ISO 9000 series by an accredited third-party certificationbody.Hazard warningsWARNIN
21、G. This British Standard calls for the use of substances and/orprocedures that can be injurious to health if adequate precautions are nottaken. It refers only to technical suitability and does not absolve the userfrom legal obligations relating to health and safety at any stage. Attention isparticul
22、arly drawn to the danger of bursts, fine jets (which can penetrate theskin), energy release of expanding gases and the use of accumulators.WARNING. Where tests are performed, the maximum working pressureconnector (MWPC) or maximum working pressure tube (MWPT) should notexceed the manufacturers maxim
23、um pressure rating.WARNING. Do not bleed off air under pressure by undoing connector nuts, asthey might separate and cause injury.The practice(s) of intermixing and/or interchanging are not condoned orrecommended within the remit of this British Standard. However, it isrecognized that, in practice,
24、system interfaces, modification requirements etc.,can make these practices necessary, and for this purpose, this British Standardrequires suitable instructions to be made available to the user (see Clause 11).Use of this documentThis British Standard is intended for use by manufacturers of connector
25、s anddesigners of systems that use connector assemblies.BSI permits the reproduction of BS 7993:2011, Table A.3. This reproduction isonly permitted where it is necessary for the user to work/record findings on thetable during each application of the standard.Presentational conventionsThe provisions
26、of this standard are presented in roman (i.e. upright) type. Itsrequirements are expressed in sentences in which the principal auxiliary verb is“shall”.BRITISH STANDARD BS 7993:2011 BSI 2011 iiiCommentary, explanation and general informative material is presented insmaller italic type, and does not
27、constitute a normative element.Requirements in this standard are drafted in accordance with The BSI guide tostandardization Section 2: Rules for the structure, drafting and presentation ofBritish Standards, subclause 11.3.1, which states, “Requirements should beexpressed using wording such as: When
28、tested as described in Annex A, theproduct shall .”. This means that only those products that are capable ofpassing the specified test will be deemed to conform to this standard.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract
29、. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.BRITISH STANDARDBS 7993:2011iv BSI 2011IntroductionTwin ferrule connectors provide metal-to-metal seal connections,non-elastomeric seals for leak-free connections to an
30、nealed stainless steel tubes.They are for use in applications where operating conditions do not allowelastomeric seals.Twin ferrule connectors are used to connect tube-to-tube and tube-to-systemcomponents, the latter through standardized ports such as pipe threads. ThisBritish Standard provides exte
31、rnal envelope and tube-end-to-port dimensionsthat facilitate designing systems that use twin ferrule connectors. It also providesmaterial specifications and minimum performance requirements to ensure theintegrity and consistency expected from this type of connector.This British Standard does not pro
32、vide detailed descriptions of the contours ofconnector components. Individual manufacturers determine the fine details oftheir connector components, and they are continually improving their designs.The nature of these metal-to-metal seals requires consistently compatiblecomponents.The twin ferrule t
33、ube connector is designed to have a maximum allowableworking pressure that is higher than that of any tubing, as shown inTables 1 to 22 of this British Standard.In the case of an all tube-ended connector, such as a union tee, the properlyselected tube is the limiting factor in the system. A connecto
34、r may, however,combine a twin ferrule connector end with another end of different form, suchas male or female pipe thread. Pressure ratings for other ends are determined inaccordance with applicable standards and may, in fact, be lower than the ratingfor the twin ferrule tube connector end. The raw
35、material from which theconnector is manufactured, either bar stock or a forging may also affect thoseratings. As a result, the rating for such other forms is generally the limitingfactor for the rating of the entire connector.1 ScopeThis British Standard specifies the characteristics of, and perform
36、ancerequirements for, the tube connector (compression) end(s) of twin ferruleconnectors made of 316 stainless steel. It also specifies requirementsfor 316 stainless steel tubes.The twin ferrule connectors in this standard are suitable for use with annealedstainless steel tubes with outside diameters
37、 from 2 mm to 38 mm and1/16in to 2 in.This British Standard is applicable to twin ferrule connectors that are intendedfor the connection of plain end tubes to other tubes and to ports in accordancewith BS EN ISO 6149-1, BS EN ISO 1179 and BS EN ISO 9974-1, and other portsagreed between the purchaser
38、 and manufacturer. It provides external envelope,tube-end-to-tube-end and tube-end-to-port dimensions that facilitate designingsystems that use twin ferrule connectors.NOTE These twin ferrule connectors can also be used with other austenitic stainlesssteel tubes, typically 304, 316L, 321, etc.BRITIS
39、H STANDARD BS 7993:2011 BSI 2011 12 Normative referencesThe following referenced documents are indispensable for the application ofthis document. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including anyamendments) appli
40、es.ANSI B1.20.1, Pipe threads, general purpose (inch)ASME/ANSI B1.1, Unified inch screw threads (UN and UNR thread form)ASME B31.3, Process piping1)ASTM A182/A182M, Standard specification for forged or rolled alloy andstainless steel pipe flanges, forged fittings, and valves and parts forhigh-temper
41、ature serviceASTM A213/A213M-10, Standard specification for seamless ferritic and austeniticalloy-steel boiler, superheater, and heat-exchanger tubesASTM A249-10, Standard specification for welded austenitic steel boiler,superheater, heat exchanger, and condenser tubesASTM A262 Standard practices fo
42、r detecting susceptibility to intergranular attackin austenitic stainless steelsASTM A269-10, Standard specification for seamless and welded austeniticstainless steel tubing for general serviceASTM A276, Standard specification for stainless steel bars and shapesASTM A351/A351M-10, Standard specifica
43、tion for castings, austenitic, forpressure-containing partsASTM A479, Standard specification for stainless steel bars and shapes for use inboilers and other pressure vesselsASTM A632-4(2009), Standard specification for seamless and welded austeniticstainless steel tubing (small-diameter) for general
44、 serviceASTM E18, Standard test methods for Rockwell hardness of metallic materialsASTM E140, Standard hardness conversion tables for metals (relationship amongBrinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficialhardness, Knoop hardness, and Scleroscope hardness)BS 1580, Unifi
45、ed screwed threadsBS 3643, ISO metric screw threadsBS 2000-2 (ISO 2977), Method of test for petroleum and its products Part 2:Petroleum products and hydrocarbon solvents Determination of aniline pointand mixed aniline pointBS 2000-15 (ISO 3016), Methods of test for petroleum and its products Part 15
46、:Petroleum products Determination of pour pointBS 2000-71.2 (ISO 3105), Method of test for petroleum and its products Part 71: Kinematic viscosity Section 2: Specifications and operating instructionsfor glass capillary kinematic viscometersBS EN 837-1, Pressure gauges Part 1: Bourdon tube pressure g
47、auges Dimensions, metrology, requirements and testingBS EN ISO 228-1, Pipe threads where pressure-tight joints are not made on thethreads Part 1: Dimensions, tolerances and designation1)This standard also gives an informative reference to ASME B31.3:2008.BRITISH STANDARDBS 7993:20112 BSI 2011BS EN I
48、SO 1179, Connections for general use and fluid power Ports and studends with ISO 228-1 threads with elastomeric or metal-to-metal sealingBS EN ISO 2719 (BS 2000-34), Determination of flash point Pensky-Martensclosed cup methodBS EN ISO 6149-1, Connections for hydraulic fluid power and general use Po
49、rtsand stud ends with ISO 261 metric threads and O-ring sealing Ports withtruncated housing for O-ring sealBS EN ISO 9227:2006, Corrosion tests in artificial atmospheres Salt spray testsBS EN ISO 9974-1, Connections for general use and fluid power Ports and studends with ISO 261 threads with elastomeric or metal-to-metal sealing ThreadedportsBS ISO 261, ISO general purpose metric screw threads General planBS ISO 5598, Fluid pow
