ASME B16.42-2011 pdf – Ductile Iron Pipe Flanges and Flanged Fittings Classes 150 and 300.
3.5.2 Other Variances. Operating variations (transients) that subject a flange or flanged fitting to pressure in excess of the rated pressure at the corresponding tt’lnpcrature are the iesponsibihty of the user, subject to the requirements of the applicable code or regulation.
3.5.3 System Hydrostatic Test. flanged pints and flanged fittings may be subjected to system hydrostatic tests at a pressure not to exceed the hydrostatic shell test pressure specified in para. 93. Testing at any higher pressure is the responsibility of the user.
4.1 Nominal Size
As applied in this Standard, the tise of 11w phrase “nominal pipe size” or the designation NI’S followed by a dimensionless number is for identifying the end connection of piping, flanges. or flanged fittings. Thc number is not necessarily the same as the inside diameter of the flange or flanged tilling. The diameter of a bolt is its nominal size. Use of nominal indicates that the stated size or dimension is on1y for designation, not measurement.
4.2 Reducing Fitting Sizes
Reducing fittings shall be designated by th size of the openings in their proper sequence as indicated in the sketches. See Fig. I.
4.3 Reducing Flange Sizes
Reducing flanges shall be designated by the two nomi• nal pipe sizes. Se examples in Note (4) of Table 2.
Except as modified herein, flanges and flanged fittings shall be marked as required in MSS SP 25.
(c) Rating Class. Numerals shall be applied giving the pressure rating class for which the product is designed.
(d) Designation. The designation “Blo’ shall be applied, preferably located adjacent to the Class designation, to indicate conformance to this Standard.
(e) Temperature. No temperature markings are required on flanges and flanged fittings, but if marked,
7.1.2 Reducing Fittings. Center-to-contact-surface or center-to-flange-edge dimensions for all openings shall be the same as those of straight size fittings of the largest opening. The contact-surlace-to-contact-surf ace dimensions for all combinations of reducers and eccentric wducrr’. shall be as llted for the larger opening.
7.1.3 Side-Outlet Fittings. Side-outlet elbows, side- outlet tees, and side-outlet crosses shall have all openings on intersecting centerlines, and the center-to- contact-surface dimensions of the side outlet shall be the same as for the largest opening. Lung-radius elbows with side outlet shall have the side outlet on the radial centerline of the elbow, and the center-to-contact-surface dimension of thc side outlet shall be the same as for the regular 90 deg elbow of the largest opening.
7.1.4 FIttings With Bases. Dimensions of bases for base elbows and base tees are shown in Tables 5 and 6.
7.1.5 SpecIal-Degree Elbows. Special-degree elbows ranging From I deg to 45 deg, inclusive, shall have the same center-to-contact-surface dimensions as 45 deg elbows; those over 45 deg to 90 deg, inclusive, shall have the same center-to-contact-surface dimensions as 90 deg elbows. The angle designation of an elbow is its deflection from straight-line flow and is aLso the angle between the flange laces.
7.2 Facings
7.21 General Class 150 fittings and companion I flanges are regularly furnished flat or with a 1.5 mm (006 in.) raised face. Class 300 fittings and companion flanges are furnished with a 1.5 mm (0.06 in.) raised face. The raised face is included in the minimum flange thickness dimensions, Q, as given in the tables.
7.2.2 FacIngs of Blind Flanges. Blind flanges need not be faced in the center if, when this center part is raised, its diameter is at least 25.4 mm (I in.) smaller than the inside diameter of the corresponding pressure class fittings, as given in thc tables. When the center part is depressed, its diameter shall not be greater than the inside diameter of the corresponding pressure-dass fittings, as given in the tables. Machining of the depressed center is not required.
7.2.3 flange Facing Finish. Contact faces shall be finished in accordance with MSS SP-6.
7.3 Flange Bolt Holes
Bolt holes are in multiples of four so that fittings may face in any quadrant. Pairs of boll holes shall straddle the centerlines.
7.4 Spot Facing
Spot lacing is required on ductile iron flanges and flanges an fittings if the flange thickness at any point does not meet the required minimum thickness, Q.