This standard covers two types of slip-on flanges, ring type and hub type, that may be used interchangeably if the dimensions given in the standard are used. The standard also covers blind flanges. The flange types and the tables that describe them are: Ring-type, slip-on flanges (Tables 2, 5, and 6); Hub-type, slip-on flanges (Tables 3 and 4); and Blind flanges (Table 7). Unless otherwise specified by the purchaser, the manufacturer will select the type to be used. The purpose of this standard is to provide purchasers and manufacturers minimum material requirements and dimensions for a variety of steel flanges for attachment to steel water pipe and fittings. Major changes made in this edition of the standard are as follows: The standard was edited and reformatted throughout; Sec. 4.1.1.2, Steel plate or bar (old Sec. 2.1.2), was revised to add carbon restrictions and the minimum yield strength was increased to 32,000 psi (220.6 MPa), representative of materials commonly used today; Sec. 4.1.2, Bolting (old Sec. 2.2), was revised to delete ASTM A307 grade A for class B and D flanges and add ASTM A193 grade B7 for class E and F flanges; Sec. 4.1.3, Gaskets (old Sec. 2.3), was revised and new Table 1, Flange Gasket Materials, Type and Thickness, was added; Sec. 4.2.5, Blind Flanges (old Sec. 3.5), was revised, reducing the maximum size of flat-plate blind flanges from 60 in. to 48 in. (1,500 mm to 1,200 mm); Tables previously numbered 1-5 were renumbered Tables 2-6, respectively; Bolt diameters for class B flanges in Tables 2 and 3 (new) were revised to match class D bolt holes; Thicknesses of some flanges were changed in Tables 2 and 6 (new); A tolerance on the diameter of the flange bore was added to Tables 2 and 3 (new) to prevent overboring hub flanges; Hub flanges greater than 96 in. (2,400 mm) were deleted from Tables 3 and 4 (new); Old Table 6, AWWA Standard Steel Hub Flanges, Class F (300 psi [2,068 kPa]0, was deleted since these flanges are identical to ANSI/ASME B16.5, and new Table 7, AWWA Blind-Flange Thickness, was added.