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1、BRITISH STANDARD CONFIRMED OCTOBER 1983 BS 1740-1: 1971 Incorporating Amendment Nos. 1, 2 and 3 Specification for Wrought steel pipe fittings (Screwed BSP thread) Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 This British St
2、andard, having been approved by the Mechanical Engineering Industry Standards Committee, was published under the authority of the Executive Board on 28 June 1971 BSI 10-1999 First published June 1951 First revision July 1965 Second revision June 1971 The following BSI references relate to the work o
3、n this standard: Committee reference MEE/121 Draft for comment 69/11845 ISBN 580 06992 3 Co-operating organizations The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departmen
4、ts and scientific and industrial organizations: Associated Offices Technical Committee Association of Consulting Engineers Association of Mining Electrical and Mechanical Engineers British Chemical Plant Manufacturers Association British Compressed Air Society British Electrical and Allied Manufactu
5、rers Association British Gear Manufacturers Association British Internal Combustion Engine Manufacturers Association British Mechanical Engineering Confederation British Pump Manufacturers Association British Steel Industry* Crown Agents for Oversea Governments and Administrations Department of Empl
6、oyment and Productivity Department of the Environment Department of Trade and Industry Department of Trade and Industry National Engineering Laboratory Electricity Council, the Central Electricity Generating Board and the Area Boards in England and Wales Engineering Equipment Users Association Gas C
7、ouncil Institution of Civil Engineers Institution of Gas Engineers* Institution of Heating and Ventilating Engineers Institution of Mechanical Engineers Institution of Mechanical Engineers (Automobile Division) Institution of Production Engineers Locomotive and Allied Manufacturers Association of Gr
8、eat Britain London Transport Executive Machine Tool Trades Association Ministry of Defence Ministry of Defence, Army Department National Coal Board National Physical Laboratory (Department of Trade and Industry) Royal Institute of British Architects Water-tube Boilermakers Association The scientific
9、 and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Institution of Municipal Engineers Metropolitan Water Board Welding Institute Wrought Fittings Mak
10、ers Association lndividual manufacturers Amendments issued since publication Amd. No.Date of issueComments 4170February 1983 5517March 1987 6240May 1990Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS
11、1740-1:1971 BSI 10-1999i Contents Page Co-operating organizationsInside front cover Forewordiii 1Scope1 2Materials1 3Screwed ends of fittings1 4Method of specifying outlets1 5Dimensions and tolerances2 6Tests2 7Hot dip galvanizing2 8Certificate of compliance3 Appendix A Method of testing the zinc co
12、ating on galvanized steel pipe fittings (copper sulphate test)Inside back cover Figure 1 50 mm 80 mm tee2 Figure 2 40 mm 25 mm 25 mm tee2 Figure 3 Internal parallel thread (Rp)3 Figure 4 External parallel thread (R)3 Figure 5 Elbow, equal4 Figure 6 Tee, equal4 Figure 7 Cross, equal4 Figure 8 Elbow,
13、equal 455 Figure 9 Elbow, reducing6 Figure 10 Elbow, male and female, equal7 Figure 11 Tee, increasing on the branch8 Figure 12 Tee, reducing on the run and branch9 Figure 13 Tee, reducing on the run only9 Figure 14 Tee, reducing on the branch10 Figure 15 Standard socket11 Figure 15A Half socket11 F
14、igure 16 Faced socket for longscrews (used in conjunction with backnut shown in Figure 22 and appropriate thread sealant)11 Figure 17 Socket, reducing12 Figure 18 Socket union13 Figure 19 Cap, flat14 Figure 20 Cap, dome14 Figure 21 Plugs15 Figure 22 Backnut (used with socket shown in Figure 16)16 Fi
15、gure 23 Bush17 Figure 24 Hexagon nipple, equal18 Table 1 Screwed ends of fittings (internal parallel thread and external taper thread)3 Table 2 Elbows, tees and crosses, equal4 Table 3 Elbows, equal 455 Table 4 Elbows, reducing6 Table 5 Elbows, male and female, equal7 Table 6 Tees, increasing on the
16、 branch8 Table 7 Tees, reducing (on the run and branch, or on the run only)9 Table 8 Tees, reducing on the branch10 Table 9 Sockets and half sockets, equal11 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 ii BSI 10-1999 Page
17、Table 10 Sockets, reducing12 Table 11 Socket unions13 Table 12 Caps14 Table 13 Plugs15 Table 14 Hexagon backnuts16 Table 15 Hexagon bushes17 Table 16 Nipples, hexagon, equal18 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 BS
18、I 10-1999iii Foreword This standard makes reference to the following British Standards: BS 21, Pipe threads for tubes and fittings where pressure-tight joints are made on the threads. BS 1387, Steel tubes and tubulars suitable for screwing to BS 21 pipe threads. BS 3894, Method for converting elonga
19、tion values for steel Part 1: Carbon and low alloy steels. This British Standard for wrought pipe fittings, first published in 1951 and revised in 1965, has been prepared in this second revision under the authority of the Mechanical Engineering Industry Standards Committee. The standard provides for
20、 a range of fittings, screwed British Standard pipe thread to BS 21, for use with steel tubes to BS 1387 and includes for the convenience of users particular of equal sockets and hexagon backnuts as specified in BS 1387. Based on experience and usage rates the range of fittings has been considerably
21、 reduced from that contained in the 1965 edition, and no reference is now made to side outlet fittings. Similarly, the range of sizes for some of the fittings retained in this standard has been reduced. Fittings of other types and sizes of outlet not covered by this standard can be made to special o
22、rder. Experience has also shown that there is no requirement for wrought iron fittings and consequently all reference to wrought iron fittings has been deleted from this standard. The metric nominal sizes are based upon international agreement. Other dimensions, except for the sizes of hexagons whic
23、h have been selected from those in BS 4229, “Sizes of non-ferrous and ferrous bars”, Part 2, “Ferrous bars”, have been converted in accordance with BS 350, “Conversion factors and tables”, Part 2, “Detailed conversion tables”, and have been rounded to values which ensure practical interchangeability
24、. Pieces, longscrews, barrel nipples, close taper nipples, running nipples, bends, springs and return bends are covered in BS 1387. NOTE 1In this standard all pressures are gauge pressures and are expressed in N/m2 or agreed multiples thereof. 1 bar = 105 N/m2. A British Standard does not purport to
25、 include all the necessary provisions of a 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,
26、pages i to iv, pages 1 to 18, an inside back cover 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. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19
27、GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 BSI 10-19991 1 Scope This Part of this British Standard specifies requirements for welded and seamless wrought pipe fittings o
28、f nominal size 6 mm to 150 mm inclusive, for use with steel tubes to BS 1387, screwed to BS 21 R-series thread. NOTEThe titles of the British Standards referred to in this standard are listed on page iii. 2 Materials 2.1 The steel from which the fittings are made shall show on test a tensile strengt
29、h of from 330 N/mm2 to 470 N/mm2 1) and a percentage elongation on a gauge length of 5.65 So of not less than 20 %, where So is the original cross-sectional area of the test piece. Where other gauge lengths are used the corresponding elongation on 5.65 So can be obtained as shown in BS 3894-1. 2.2 W
30、here fittings are welded during manufacture, the steel shall show on analysis not more than 0.06 % of sulphur and not more than 0.06 % of phosphorus. 2.3 If cold worked bar is used for the manufacture of fittings, the effects of the cold working shall be removed, so that the material of the final pr
31、oduct shall show the mechanical properties specified above. 3 Screwed ends of fittings 3.1 General dimensions. All dimensions for the screwed ends of fittings shall be in accordance with Table 1. NOTEWhile fittings may be specified in metric dimensions, the thread designations of these fittings are
32、specified in fractional form, in accordance with BS 21, e.g. BS 1740, hexagon bush, 15 10, screwed R“ Rp). 3.2 Internal and external threads. Internal threads on the ends of fittings shall be parallel (Rp) and external threads shall be taper (R), and both threads shall comply with the appropriate re
33、quirements of BS 21. NOTEFor pressure duty, fittings complying with the requirements of this standard are not suitable for use with G series threads to BS 2779 since no machined face exists upon which a sealing device may act. 3.3 Alignment. The axes of screw threads shall be coincident with the tru
34、e axes of the fittings within 1 in 200 on the run and 1 in 125 on the branch. 4 Method of specifying outlets 4.1 Equal fittings. Where all outlets are of the same size, they shall be specified by that one size irrespective of the number of outlets. 4.2 Unequal fittings. When outlets are of differing
35、 sizes they shall be specified as follows: 4.2.1 Fittings having two outlets. The larger outlet shall be specified first. 4.2.2 Tees. When two sizes are specified, the first shall apply to both ends of the run, the second to the branch, e.g. a 50 mm 80 mm tee (Figure 1). When three sizes arc specifi
36、ed, the first two shall apply to the ends of the run, the larger end being specified first, and the third to the branch, e.g. a 40 mm 25 mm 25 mm tee (Figure 2). 1) 1 N/mm2 = 1 MN/m2. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1
37、:1971 2 BSI 10-1999 5 Dimensions and tolerances 5.1 Dimensions. Fittings complying with this Part of this British Standard shall conform to the dimensions in Table 1 to Table 16 as appropriate. 5.2 Tolerances 5.2.1 The lengths of reducing sockets, caps, hexagon bushes and hexagon nipples, and the ce
38、ntre to face dimensions of elbows, tees and crosses are minima and the plus tolerance allowed shall be as follows: 5.2.2 The lengths of socket unions are minima and the plus tolerance allowed shall be as follows: 6 Tests 6.1 Pressure tests 6.1.1 By the manufacturer. Each fitting, after being screwed
39、, and before any protective coating other than galvanizing has been applied, shall be capable of withstanding, without showing any signs of leakage, hydraulic and air tests as specified in 6.1.1.1 and 6.1.1.2. 6.1.1.1 Hydraulic test. The application of an internal hydraulic pressure of 5 MN/m2 (50 b
40、ar). 6.1.1.2 Air test. The application of an internal air pressure of 0.7 MN/m2 (7 bar) whilst the fitting is completely immersed in water or light oil. 6.1.2 Test requirements by the purchaser. If the purchaser requires either of the tests specified in 6.1.1.1 and 6.1.1.2 to be made on fittings sup
41、plied to his order, he shall state this in his enquiry and order, and indicate the test or tests required. 7 Hot dip galvanizing 7.1 Where fittings are to be galvanized, they shall first be thoroughly descaled, washed as required and dipped in a bath of molten zinc containing not less than 98.5 % by
42、 weight of zinc at a temperature suitable to produce a complete and uniformly adherent coating of zinc. 7.2 Galvanized screwed fittings shall be galvanized before screwing. 7.3 The galvanizing shall be capable of passing the test specified in Appendix A and the test shall preferably be made before a
43、ny machining operation has been performed. 7.4 Should a test on the galvanizing be required, this shall be stated by the purchaser in his enquiry and order. One fitting in every 500, or part thereof, shall be sampled in accordance with Appendix A. Figure 1 50 mm 80 mm teeFigure 2 40 mm 25 mm 25 mm t
44、ee Length or centre to face dimension (mm) Up to and including 25 Over 25 to 40Over 40 to 65Over 65 to 75Over 75 to 150Over 150 Tolerance (mm)1.53.04.56.08.010.0 Length (mm)Up to and including 40Over 40 to 65Over 65 to 75Over 75 to 110 Tolerance (mm) 6101216 Licensed Copy: sheffieldun sheffieldun, n
45、a, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 BSI 10-19993 8 Certificate of compliance The manufacturer shall, upon request, furnish the purchaser with a certificate as evidence that the fittings supplied comply in all respects with the appropriate requirements of
46、this British Standard. Table 1 Screwed ends of fittings (Internal parallel thread and external taper thread) Figure 3 Internal parallel thread (Rp)Figure 4 External taper thread (R) Nominal size of outlet Minimum outside diameter D Minimum outside diameter of body behind external thread E Minimum in
47、side diameter of body behind internal thread d inmmmmmmmm ( ! ) 6 8 10 15.0 18.5 22.0 9.8 13.3 16.8 8.6 11.4 15.0 “ # 1 15 20 25 27.0 32.5 39.5 21.1 26.6 33.4 18.6 24.1 30.3 1! 1“ 2 32 40 50 49.0 56.0 68.0 42.1 48.0 59.8 39.0 44.8 56.7 2“ 3 4 65 80 100 84.0 98.0 124.0 75.4 88.1 113.3 72.2 84.9 110.1
48、 5 6 125 150 151.0 178.0 138.7 164.1 135.5 160.9 NOTEFor particulars of threads, see BS 21-1. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 4 BSI 10-1999 Table 2 Elbows, tees and crosses, equal Figure 5 Elbow, equalFigure 6
49、Tee, equalFigure 7 Cross, equal Nominal size of outletsMinimum length centre to face A inmmmm ( ! ) 6 8 10 16 22 24 “ # 1 15 20 25 32 35 43 1! 1“ 2 32 40 50 51 52 64 2“ 3 4 65 80 100 76 89 115 5 6 125 150 140 160 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:08:19 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1740-1:1971 BSI 10-19995 Table 3 Elbows, equal 45 Figure 8 Elbow, equal 45 Nominal size of outletsMinimum lengt