ASME B16.42-2016 pdf download.Ductile Iron Pipe Flanges and Flanged Fittings.
3.2 Ratings of Flanged Joints Ratings in this Standard apply to flanged joints that conform to the limitations on bolting in para. 6.2 and on gaskets in para. 7.8, and which are made up in accor- dance with good practice for alignment and assembly. See also para. 3.4. Use of the ratings for flanged joints not conforming to these limitations is the sole responsibility of the user. A flanged joint is composed of separate and indepen- dent, although interrelated, components: the flanges, the gasket, and the bolting, which are assembled by another influence, the assembler. Proper controls must be exer- cised in the selection and application for all these ele- ments to attain a joint that has acceptable leak tightness. Special techniques, such as controlled bolt tightening, are described in ASME PCC-1. If the two flanges in a flanged joint do not have the same pressure–temperature ratings, the rating of the joint at any temperature is the lower of the two flange ratings at that temperature.
5 MARKING Exceptas modified herein, flanges and flanged fittings shall be marked as required in MSS SP-25. (a) Name. The manufacturer’s name or trademark shall be applied. (b) Material. The word “DUCTILE,” or “DI” where space does not permit “DUCTILE,” shall be applied. (c) Rating Class. Numerals shall be applied giving the pressure rating class for which the product is designed. (d) Designation. The designation “B16” shall be applied,preferablylocatedadjacenttotheClassdesigna- tion, to indicate conformance to this Standard.
7.5 Reducing Flanges 7.5.1 Drilling, Outside Diameter, Thickness, and Facing Dimensions. Flange drilling, outside diameter, thickness, and facing are the same as those of the stan- dard flange of the size from which the reduction is being made. 7.5.2 Threaded Flanges. The hub dimensions shall be at least as large as those of the standard flange of the size from which the reduction is being made. The hub may be larger or may be omitted, as detailed in Table 2.
7.7 Stud Bolts, Bolts, and Nuts 7.7.1 Alloy Bolting. Alloy steel stud bolts, threaded at both ends or full length, or heavy hex bolts may be used. Heavy hex nuts shall be used with all alloy steel bolting. 7.7.2 Carbon Steel Bolting (a) Bolts smaller than 3 ⁄ 4 diameter shall have square heads or heavy hex heads. Nuts shall be heavy hex. (b) Bolts 3 ⁄ 4 diameter and larger shall have square heads or hex heads. Nuts shall be hex or heavy hex.ASME B16.42 pdf download.