Since the first edition of the AWWA Standard C207 was printed in 1952, AWWA flanges have commonly been used in waterworks, wastewater, slurry, plant piping, and other light duty applications. Pressure ratings for AWWA flanges range from the Class B flange rated at 86 psi to the Class F flange rated at 300 psi. The AWWA C207-01 standard describes 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 describes blind flanges. Flanges described in the AWWA C207-01 tables are intended for use with steel pipe, fittings or appurtenances meeting the requirements of ANSI/AWWA C200, ANSI/AWWA C208, ASTM A134, ASTM 139, or other equivalent standards. It is further intended that these flanges be attached by welding in accordance with AWWA C207-01 Sec.4.3.
 | 1. Ring flanges available overbored or counterbored per customer specification. 2. Bolt holes shall be drilled 1/8th inch larger in diameter than the nominal diameter of the bolt, except for flanges larger than 84 inch in diameter which shall be drilled 3/16th inch larger than the nominal diameter of the bolt. 3. Drilling same as ANSI/ASME B16.1 125 lb and B16.5 150 lb pattern. 4. Flanges available overdrilled to accommodate insulators. 5. AWWA recommends the use of dished head assemblies as alternate to blind flanges, sizes over 72" nominal. 6. AWWA C207-01 Class B and D Hub Flanges are identical to Industry Standard Class 125 Light Weight Flanges. |
