BS 669-2-1997 Flexible hoses end fittings and sockets for gas burning appliances - Specification for corrugated metallic flexible hoses covers end fittings and sockets for catering.pdf

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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 669 : Part 2 : 1997 IC

2、S 83.140.40; 91.140.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Flexible hoses, end fittings and sockets for gas burning appliances Part 2. Specification for corrugated metallic flexible hoses, covers, end fittings and sockets for catering appliances burning 1st, 2nd an

3、d 3rd family gasesBS 669 : Part 2 : 1997 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 April 1997 BSI 1997 First published as BS 669 April 1936 Second edition Octob

4、er 1952 Third edition January 1960 First published as BS 669 : Part 2 February 1988 Second edition December 1995 Third edition April 1997 The following BSI references relate to the work on this standard: Committee reference GSE/1 Draft for comment 96/707106 DC ISBN 0 580 27160 9 Amendments issued si

5、nce publication Amd. No. Date Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee GSE/1, Gas fittings and connections, upon which the following bodies were represented: British Combustion Equipment Manufacturers

6、 Association British Gas plc British Rubber Manufacturers Association Ltd. British Turned-parts Manufacturers Association Council for Registered Gas Installers Energy Industries Council Health and Safety Executive LP Gas Association Society of British Gas Industries The Association of Catering Equip

7、ment Manufacturers and Importers The Employers Association of Catering Equipment Engineers Ltd.BS 669 : Part 2 : 1997 BSI 1997 i Contents Page Committees responsible Inside front cover Foreword ii Section 1. General 1.1 Scope 1 1.2 References 1 1.3 Definitions 1 Section 2. Flexible connection 2.1 Ge

8、neral 2 2.2 Design and dimensions 2 2.3 Materials 3 2.4 Methods of assembly 4 2.5 Performance 4 Section 3. Requirements for end fittings and sockets 3.1 General 8 3.2 Materials 8 3.3 Performance of the end fitting assembly 9 3.4 Installation instructions 12 3.5 Marking 13 Tables 1. Flow rate through

9、 flexible connection assemblies 2 2. Dimensions of flexible connection assemblies 3 3. Properties and methods of test for synthetic covers 4 4. Test conditions 5 5. Minimum locking torques 8 Figures 1. Rolling bend fatigue test 6 2. Torsional loading test 7 3. Pull test 9 4. Impact test apparatus 10

10、 5. Impact test 11 6. Drop test 12 List of references 14ii BSI 1997 BS 669 : Part 2 : 1997 Foreword This Part of BS 669 has been prepared by Technical Committee GSE/1. It supersedes BS 669 : Part 2 : 1995, which is withdrawn. The standard was first published in 1936 and revised in 1952 and 1960. Sin

11、ce then, three major changes have occurred, namely the introduction of 2nd and 3rd family gases and the adoption of the metric system. In addition the King report1, published in 1977, preferred that connections to gas cooking appliances should be flexible and should incorporate a plug and socket tha

12、t seals automatically when the plug is withdrawn. The 1960 edition of BS 669 was reviewed under the direction of the Gas Standards Committee and the revised standard was published in two Parts: Part 1 : Specification for strip-wound metallic flexible hoses, covers, end fittings and sockets for domes

13、tic appliances burning 1st and 2nd family gases Part 2 : Specification for corrugated metallic flexible hoses, covers, end fittings and sockets for catering appliances burning 1st and 2nd family gases This Part of BS 669 deals with corrugated metallic flexible connections for catering equipment. The

14、 1995 revision included requirements for 3rd family gases. This revision is introduced to permit alternative types of construction. Attention is drawn to the stated manufacturing tolerances and the need for careful quality control as outlined in BS EN ISO 9000. Guidance on the use of flexible connec

15、tions is given in BS 6173 for gas-fired catering appliances. Pressure class 1, type B corrugated hoses specified in BS 6501 : Part 1 in general meet the requirements of this standard. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This

16、document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 14, an inside back cover and a back cover.Section 1 BS 669 : Part 2 : 1997 BSI 1997 1 1) 1 mbar = 100 N/m 2 = 100 Pa. Section 1. General 1.1 Scope This Part of BS 669 specifies the minimum requirements for corrugated

17、 metallic flexible hoses, covers, end fittings and quick disconnect couplings or sockets for use with catering appliances burning 1st, 2nd and 3rd family gases at a nominal inlet pressure not exceeding 50 mbar 1) . 1.2 References 1.2.1 Normative references This Part of BS 669 incorporates, by dated

18、or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on page 14. For dated references, only the edition cited applies; any subsequent amendments to or revisions of the cited publicati

19、on apply to this British Standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 1.2.2 Informative references This Part of BS 669 refers to other publications that provide in

20、formation or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 1.3 Definitions For the purposes of this Part of BS 669 the definitions given in BS 1179 : 1967 and in BS 1179

21、 : Part 6 apply together with the following. 1.3.1 braid A layer (or layers) of cylindrically woven wires covering the hose. 1.3.2 corrugated metallic flexible hose The flexible gas-tight metal element of an assembly without end fittings or covering. 1.3.3 cover Any tubular outer cover used to impro

22、ve the cleanliness of a flexible hose. 1.3.4 end fitting A component permanently factory-fitted to a flexible hose that allows gas-tight connection to other pipework and can be a plug or a thread conforming to BS 21 : 1985, with a swivel, for fitting into the appropriate wall socket or appliance. 1.

23、3.5 end fitting assembly An assembled plug and socket or union complete with swivel. 1.3.6 flexible connection The corrugated metallic flexible hose with braid, where fitted, cover and end fittings attached. 1.3.7 flexible connection assembly The complete assembly comprising flexible connection and

24、any matching socket. 1.3.8 flow rate The rate of flow of gas through a flexible connection assembly under standard conditions. 1.3.9 inside diameter The diameter of the largest sphere that can pass freely through the corrugated hose. 1.3.10 cover material A synthetic material used to cover the flexi

25、ble hose. 1.3.11 overall length The length of a flexible connection assembly, measured while it is lying straight on a flat horizontal surface. 1.3.12 plug and socket or quick disconnect coupling A two part fitting that provides quick connection and disconnection of an appliance at the gas supply, w

26、here the plug is an end fitting of the flexible connection and the socket is an installation fitting which is self-sealing as the plug is withdrawn. NOTE. The phrase quick disconnect coupling may be used interchangeably with plug and socket. A quick disconnect coupling enables 360 axial rotation of

27、the flexible hose with respect to the installation pipe fitting. 1.3.13 swivel (or rotary joint) A permanently factory-fitted device other than fittings defined in 1.3.12 that enables a continuous axial rotation of the flexible hose with respect to the installation pipe fitting or to the appliance a

28、s appropriate without reducing the gas-tightness of the flexible connection assembly. 1.3.14 restraining device A device that prohibits movement of the appliance away from the wall beyond the maximum extension of the device.2 BSI 1997 BS 669 : Part 2 : 1997 Section 2 Table 1. Flow rate through flexi

29、ble connection assemblies Nominal size of flexible connection assembly (inlet connection) Diameter (min.) Overall length of flexible connection assembly Tolerance on length Air flow rate (min.) Air pressure drop (max.) mm mm mm m 3 /h mbar 6 1000 215 +5 5 0.3 0.58 8 1000 215 +5 5 0.6 0.58 10 1000 21

30、5 +5 5 1.3 0.58 15 1000 215 +5 5 3.0 0.58 1 20 1000 215 +5 5 5.0 0.58 1 25 1000 215 +5 5 9.0 0.58 1 32 1000 215 +5 5 12.0 0.58 Section 2. Flexible connection 2.1 General 2.1.1 Size The nominal sizes of the flexible connection assembly shall be , ,1 ,1, and 1, in accordance with BS 21 : 1985. 2.1.2 F

31、low rate The flow rate through the flexible connection assembly when passing air shall not be less than that given in table 1 at the appropriate pressure drop. 2.2 Design and dimensions 2.2.1 Corrugated metallic flexible hose The hose shall be without circumferential joins and shall be manufactured

32、from: a) seamless tube; or b) single longitudinally butt-welded tube. The corrugations shall be annular and shall be of uniform height and pitch and continuous along the length of the hose, except for that section of the hose at the terminals required for transition. After forming the corrugated hos

33、e, the surface shall be free from any defects, e.g. scores or dents, which might cause premature failure. Helical hoses shall only be used in designs which incorporate a transition section of plain tube. The transition section shall be supported by the fitting and used with both welded joints and me

34、chanical fittings. 2.2.2 Braid The flexible connection shall be either braided or unbraided. Where braid is used it shall conform to the requirements in 2.3.3 and 2.4.1. 2.2.3 Cover For the purpose of cleanliness, a smooth outer cover of synthetic material shall be fitted to each flexible connection

35、. This cover shall: a) extend over all parts of the flexible metallic hose that are capable of being bent or flexed and be a tight fit on the end connections; b) have no adverse effect on the performance of the metallic hose; c) have a minimum wall thickness of 0.5 mm after fitting; d) be coloured y

36、ellow ochre in accordance with BS 4800 : 1989, colour code 08C35 or 10E53.Section 2 BS 669 : Part 2 : 1997 BSI 1997 3 Table 2. Dimensions of flexible connection assemblies Nominal size of flexible connection assembly (inlet connection) Inside diameter (min.) Overall length of flexible connection ass

37、embly Tolerance on length Wall thickness 1) (min.) mm mm mm mm mm mm mm 6 500 1000 1250 1500 215 +5 5 0.13 8 500 1000 1250 1500 215 +5 5 0.20 10 500 1000 1250 1500 215 +5 5 0.20 15 1000 1250 1500 215 +5 5 0.20 1 20 1000 1250 1500 215 +5 5 0.20 1 25 1000 1250 1500 215 +5 5 0.25 1 32 1000 1250 1500 21

38、5 +5 5 0.25 1) Measured at three positions over the length of the corrugated tube. 2.2.4 Dimensions The dimensions of the flexible connection assemblies shall be as given in table 2. 2.3 Materials 2.3.1 Corrugated metallic flexible hose Where welded fittings are used, the hose shall be manufactured

39、from: grade number 1.4306, 1.4404, or 1.4541 austenitic stainless steel, as specified in BS EN 10088-2 : 1995. Where mechanically attached end fittings are incorporated in the assembly, the hose shall be manufactured from either: grade number 1.4306, 1.4404, or 1.4541 austenitic stainless steel, as

40、specified in BS EN 10088-2 : 1995; or stainless steel that meets or exceeds the requirements for grade number 1.4301 of BS EN 10088-2 : 1995, vacuum annealed after forming, and the finished product, including any formed part of the hose, being production tested in accordance with BS 5903 : 1980, Met

41、hod A. 2.3.2 Covers The properties of covers and their methods of test shall be as given in table 3. Covers shall conform to the requirement of 2.5.3. The covers material shall not react with the corrugated metallic hose to the detriment of the hose or cover. Non-chlorinated materials shall contain

42、not more than 50 ppm of chlorides (total content). For covers manufactured from other materials, the free chloride content shall not exceed the value given in table 3, when measured using chemically suppressed ion chromotography (CSIC). The cover sample for this test shall have a minimum length of d

43、econvoluted surface of 100 mm and be held in suspension at 60 C for 24 h to ascertain the free ion content. NOTE. Calculation of the surface area should take account of the fact that leaching will occur from both inner and outer surfaces. The cover shall have a minimum wall thickness of 0.5 mm after

44、 fitting.4 BSI 1997 BS 669 : Part 2 : 1997 Section 2 Table 3. Properties and methods of test for synthetic covers Property Non-chlorinated requirement 1) PVC requirement Method of test Tensile strength (min.) 10 MPa 6 MPa BS 903 : Part A2 : 1995 Type 2 dumb-bell test pieces Elongation at break (min.

45、) 200 % 350 % BS 903 : Part A2 : 1995 Type 2 dumb-bell test pieces Ozone resistance No cracks No cracks BS 903 : Part A43 : 1990 300 pphm ozone; 20 % strain for 72 h at (38 2) C Heat ageing No cracks No cracks BS 903 : Part A19 : 1986 168 h at (175 2) C Free chloride content 0.4mg/cm 2 See 2.3.2 1)

46、Cover normally compounded from a polyolefin, pigment and stabilizer. 2.3.3 Braid Where the braid is to be welded it shall be manufactured from fully annealed austenitic stainless steel wire conforming to grade 316S31, 321S31, as specified in BS 1554 : 1990 or 304S31 (0.045 % carbon max.), as given i

47、n table 1 of BS 6501 : Part 1 : 1991. Where the braid is not to be welded, i.e. where the flexible connection incorporates mechanically attached end fittings, the braid shall be manufactured from austenitic stainless steel of grade 304S31 conforming to BS 1554 : 1990; or fully annealed austenitic st

48、ainless steel wire conforming to grade 316S31, 321S31, as specified in BS 1554 : 1990 or 304S31 (0.045 % carbon max.) as given in table 1 of BS 6501 : Part 1 : 1991. 2.3.4 Ferrules Where ferrules are used, they shall be manufactured from the stainless steel specified in 3.2.1a. 2.3.5 Restraining dev

49、ice The restraining device shall withstand a minimum tensile load of 500 kg and shall be covered for cleanliness. The necessary mounting hardware to attach the restraining device to both the appliance and the fixed mounting point shall be provided with the restraining device. 2.4 Methods of assembly 2.4.1 Braided assemblies Construction shall be by one of the following methods. a) The braid shall be passed through a ferrule and shall be welded to the end of the corrugated hose and to the ferrule so that the braid is bo