scope:

This standard covers two types of flange cross sections that may be used interchangeably if the dimensions given in the standard are used: (1) the ring type slip-on flange (Table 1) and (2) the hub type slip-on flange (Tables 2 and 3). Unless otherwise specified by the purchaser, the supplier is free to select the type.

Blind flanges.

Blind flange dimensions are not included in this standard. The purchaser shall supply thickness dimensions when ordering blind flanges.

Intended use.

Flanges in this standard are intended for use with steel pipe, fittings, or appurtenances meeting the requirements of AWWA C200 and C208, ASTM A 134, A 139, and A 211, or other equivalent standards. It is intended that flanges be attached by welding in accordance with Sec. 4 of this standard.

Pressure ratings.

The following pressure ratings apply to flanges covered by this standard:

Class B flanges are suitable for water pressures up to and including 86 psi. This rating is identical with that for Class B cast-iron fittings for a 200-ft head of water.

Class D flanges are suitable for water pressures as follows:

Sizes 4−12 in.-175 psi.

Sizes greater than 12 in-150 psi.

Class E flanges are suitable for water pressures up to and including 275 psi, which corresponds with ANSI B16.5 at 100 F (37 C). The dimensions for standard sizes up to and including 24 in. nominal diameter flanges are the same as listed for 150-lb flanges in ANSI B16.5, except that they shall be faced in accordance with Sec. 3.2 of this standard.

The ratings are for water pressures under conditions and temperatures customary in water works service. The design pressure should include anticipated allowance for surge pressures. Test pressure for equipment using flanges in this standard shall not exceed 150 per cent of the service pressure ratings previously given.