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.