1、BRITISH STANDARD CONFIRMED OCTOBER 1993 BS3293:1960 Incorporating Amendment No.1 Specification for Carbon steel pipe flanges (Over24 inches nominal size) For the petroleum industryBS3293:1960 This British Standard, having beenapproved by the Petroleum Equipment Industry Standards Committee and endor
2、sed by the Chairman of the Engineering Divisional Council, was publishedunder the authority ofthe General Council on 30December 1960 BSI 03-2000 The following BSI references relate to the work on this standard: Committee reference PEE/2 Draft for comment CZ(PEE) 9923 ISBN 0 580 03066 0 Co-operating
3、organizations The Petroleum Equipment Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: British Iron the flange designations quoted are for ident
4、ification purposes only. 2 Designation and pressure temperature ratings To facilitate ordering and to ensure interchangeability, flanges in this standard are designated as Classes150,300,400 and600. These class designations, however, do not imply specific pressure/temperature ratings in the same man
5、ner as flanges in accordance with BS1560. Users shall therefore satisfy themselves that the flanges selected are adequate for the intended duty. Where it is required to use the flanges in this standard at temperatures below20 F reference should be made to BS3351. 3 Flange facings For Class150 flange
6、s, raised facings only are specified. For Classes300,400 and600 flanges, both raised facings and ring-joint facings are specified, and the purchaser shall specify when ordering, which type of facing is required. The 1 / 16in high facing is the regular type of raised facing for flanges of Classes150
7、and300, and the 1 / 4in high facing is the regular type of raised facing for flanges of Classes400 and600. 4 Nominal sizes The nominal size of a flange as shown in the tables is the same as the nominal pipe size. Section 2. Materials 5 Materials for flanges Flanges shall be carbon steel forgings to
8、the following specification, full details of which are contained in BS1503 Material to BS1503-161 Grade28 Class A or B. (A.S.T.M. A105, GradeI) may be supplied if specified by the purchaser 6 Bolting materials All bolting material shall comply with BS1750 1) . For pressures and temperatures above275
9、 psi and450 F, bolts shall be of alloy steel in conformity with Part1 of the above standard, and nuts shall be of carbon or alloy steel in conformity with Part2. For pressures and temperatures up to and including275 psi and450 F, carbon steel bolts and nuts complying with Part3 of the above standard
10、 may be used. Section 3. Dimensions and tolerances 7 Flanges a) Flange dimensions. Flange dimensions shall conform to those given in Table 1, Table 3, Table 5 and Table 7. In no case, regardless of the type of facing provided and the tolerances referred to in Clause7 b), shall the minimum thickness
11、of a flange, as specified in the tables listed above, be reduced in order to provide adequate height for a raised facing or adequate depth for a ring groove, except where a Class150 or a Class300 flange is provided with a 1 / 16in raised facing, when the height of the facing is included in the minim
12、um flange thickness specified. b) Tolerances on flange dimensions. The following are the tolerances permitted on flange dimensions: British Standard Comparable A.S.T.M. Standard BS 1503-161 Grade32 Class A or B. A105 Grade II 1) “Bolting for the petroleum industry ”. i) Slip-on welding flanges (Tabl
13、e 1, Table 3, Table 5 and Table 7). On flange bore Dimension B 1 + 1 / 16 in 0 in On flange thickness Dimension C + 3 / 16 in 0inBS3293:1960 2 BSI 03-2000 8 Flange facings and gaskets a) Flange facing dimensions. Flange facing dimensions shall conform to those given in Table 2, Table 4, Table 6 and
14、Table 8. Raised facings shall be finished in accordance with the requirements of BS1560 2) . Ring-joint grooves shall be machined true with the face and concentric with the bolt circle and the bore of the flanges. Grooves shall be finished smooth and shall be free from ridges and chatter marks. b) T
15、olerances on flange facing dimensions. The following are the tolerances permitted on flange facing dimensions: c) Gasket dimensions. Dimensions of compressed asbestos fibre gaskets for use with raised facings are given in Table 9. Dimensions of ring-joint gaskets are given in Table 10. d) Tolerances
16、 on gasket dimensions. The following are the tolerances permitted on gasket dimensions: i) Compressed asbestos fibre gaskets (Table 9). Tolerances on these gaskets are not specified. ii) Ring-joint gaskets (Table 10) 3) . 9 Flange bolting dimensions The number of bolts, their size and the bolt circl
17、e diameter for each class and size of flange shall be as given in Table 2, Table 4, Table 6 and Table 8. Bolt holes shall be pitched evenly around the bolt circle. 10 Spot-facing and back-facing of flanges Flanges need not be spot-faced or back-faced provided that their backs are parallel, within1 ,
18、 to their faces and the fillets of their hubs do not interfere with the full bearing of the fastening nuts. On overall length through hub Dimension Y 1(Table 1) Dimension Y (Table 3, Table 5, Table 7) 1 / 8in ii) Welding-neck flanges (Table 1, Table 3, Table 5 and Table 7). a On flange bore Dimensio
19、n B 2 + 1 / 8in 1 / 16in On flange thickness Dimension C + 3 / 16 in 0 in On overall length through hub Dimension Y 2 (Table 1) Dimension Y (Table 3, Table 5, Table 7) 1 / 8in a Outside diameter of welding end of hub Dimension A (Table 1) Dimension A 2 (Table 3, Table 5, Table 7) + 5 / 32in 1 / 32in
20、 a In no case, regardless of the tolerances permitted on flange bore (B 2 ) and outside hub diameter (A and A 2 ), shall the thickness of the welding end of a welding-neck flange be less than87 1 / 2per cent of the nominal thickness of the pipe to which it is to be attached. 2) BS1560, “Steel pipe f
21、langes and flanged fittings (Nominal sizes 1 / 2in to24 in) for the petroleum industry”. i) Raised facings (Table 2, Table 4, Table 6 and Table 8). On outside diameter of raisedface Dimension R 1 / 64in ii) Ring-joint facings (Table 4, Table 6 and Table 8). On pitch diameter of groove Dimension P 0.
22、005 in On width of groove Dimension F 0.008 in On depth of groove Dimension E + 1 / 64in 0 in On23 flank angle of groove 1 / 2 On average pitch diameter of ring Dimension P 0.007 in On width of ring Dimension A 0.008 in On height of ring DimensionH a 1 / 64in. On width of flat Dimension C 0.008 in O
23、n corner radius Dimension R 1 / 64in On23 flank angle of ring 1 / 2 a A plus tolerance of 3 / 64inch on height is permitted provided that the variation in the height of any given ring does not exceed 1 / 64inch throughout its entire circumference. 3) Extracted from A.S.A. Std. B 16.20, “Ring-joint g
24、askets and grooves for steel pipe flanges” (obtainable from the British Standards Institution).BS3293:1960 BSI 03-2000 3 When spot-facing is required its diameter shall not be less than the dimension across the corners of the appropriate nut plus 1 / 8inch. When a spot-facing cuts into the fillet of
25、 a flange its diameter shall not exceed the dimension across the corners of the nut by more than 3 / 16inch. When a flange is back-faced the fillet may be reduced but not eliminated entirely. A sharp corner at the junction of the flange and its hub shall not be permitted. The specified minimum thick
26、ness of any flange whether or not it is spot-faced or back-faced shall not be exceeded by more than the tolerance permitted under Clause7, nor shall the process of spot-facing or back-facing reduce its thickness at any point to less than the specified minimum. Section 4. Inspection 11 Inspection The
27、 purchaser or his representative shall have free access, at all reasonable times, to those parts of the manufacturers works engaged upon his contract and shall be at liberty to inspect, at any stage of manufacture, the materials covered by this contract. He shall be at liberty to reject any material
28、 which does not comply with the requirements of this standard. NOTEThis standard does not make provision for the pressure testing of loose flanges. These may be tested after attachment to pipe or equipment. The test pressure will then depend on the requirements of the Code to which the pipe or equip
29、ment has been fabricated. 12 Repair of defects Defects which do not impair the strength of a flange may be welded by a procedure approved by the purchaser. They shall be cleaned out to sound metal before welding and shall be submitted to the purchasers inspector for approval in this condition, after
30、 which they may be welded if the inspector so agrees. Such welds need not be heat treated, unless required by the inspector. When the welding of defects is permitted the welding rod shall be such as to produce a weld having characteristics similar to the parent metal. Section 5. Marking 13 Marking T
31、he following markings are required on flanges covered by this standard: a) The manufacturers name or trade mark. b) BS3293 c) The word “Steel”. d) Nominal pipe size in inches. e) On flanges provided with ring-joint facings, the letter “R” followed by the appropriate ring number, this marking being l
32、ocated on the flange edge. Section 6. Preparation and despatch 14 Preparation Painting of finished flanges shall be optional to the manufacturer, unless otherwise specified by the purchaser. Machined surfaces shall be well covered with an approved rust-inhibiting composition. 15 Despatch Flanges sha
33、ll be fastened together in such a manner that they are paired and no flange facings remain exposed. Exposed facings of single flanges shall be protected over their entire surface with a suitable close-fitting protector securely attached at not less than four points. The type of protector and method
34、of attachment shall be approved by the purchaser. Other methods of preparation for despatch shall be subject to agreement between the purchaser and the manufacturer.BS3293:1960 4 BSI 03-2000 Table 1 Dimensions of flanges, class150 1 2 3 4 5 6 7 8 9 10 Nominal pipe size Outside diameter of flange Thi
35、ckness of flange min. Outside diameter of large end of hub Outside diameter of small end of hub: Welding neck Length through hub Fillet radius Flange bore Slip-on Welding-neck Slip-on Welding-neck O C X A Y 1 Y 2 R B 1 B 2 in 26 28 30 32 34 36 38 40 42 44 46 48 in 34 1 / 4 36 1 / 2 38 3 / 4 41 3 / 4
36、 43 3 / 4 46 48 3 / 4 50 3 / 4 53 55 1 / 4 57 1 / 4 59 1 / 2 in 2 2 1 / 16 2 1 / 8 2 1 / 4 2 5 / 16 2 3 / 8 2 3 / 8 2 1 / 2 2 5 / 8 2 5 / 8 2 11 / 16 2 3 / 4 in 28 1 / 2 30 3 / 4 32 3 / 4 35 37 39 1 / 4 41 3 / 4 43 3 / 4 46 48 50 52 1 / 4 in 26 28 30 32 34 36 38 40 42 44 46 48 in 3 3 / 8 3 7 / 16 3
37、1 / 2 3 5 / 8 3 11 / 16 3 3 / 4 3 3 / 4 3 7 / 8 4 4 4 1 / 16 4 1 / 8 in 5 5 1 / 16 5 1 / 8 5 1 / 4 5 5 / 16 5 3 / 8 5 3 / 8 5 1 / 2 5 5 / 8 5 5 / 8 5 11 / 16 5 3 / 4 in 1 / 4 1 / 4 1 / 4 5 / 16 5 / 16 5 / 16 3 / 8 3 / 8 3 / 8 7 / 16 7 / 16 7 / 16 in 26 1 / 4 28 1 / 4 30 1 / 4 32 1 / 4 34 1 / 4 36 1
38、/ 4 38 1 / 4 40 1 / 4 42 1 / 4 44 1 / 4 46 1 / 4 48 1 / 4 in To be specified by the purchaser NOTE 1For relevant drilling, bolting and facing dimensions, see Table 2. NOTE 2For tolerances permitted on flange dimensions, see Clause7. NOTE 3The hubs of slip-on welding flanges may be cylindrical or, al
39、ternatively, may have a draft of not more than7 on the outside surface for forging purposes. NOTE 4Each sketch at the head of this table depicts a flange with a 1 / 16in raised facing. The dimensions C, Y 1 , and Y 2 , therefore, include the height of the facing (see Clause 7). If any other type of facing is required its height shall be additional to the minimum flange thickness.
