Flange Joint - 4” - 144”
A flange is used at a joint that may require future disassembly such as connections to valves and meters, access port covers, and connections to existing pipe. Flanges are generally shop attached but can be furnished loose for field attachment when such flexibility is required. Connections are made using bolts that connect two flanges separated by a gasket. Given this configuration, flanges afford the designer a convenient location to provide electrical isolation between sections of installed pipe by virtue of insulating kits. Flanges can be furnished as either of two types, ring or hub, with ring flanges being the industry standard. Blind flanges are configured without a center hole and are generally used for covers at access ports, or for closure at the end of a pipeline. Requirements for flanges, bolts, nuts and gaskets for standard water pipe service are defined in the AWWA standard for flanges, C207. For conditions outside of the guidelines of AWWA C207, use of alternate standards may be appropriate, including ASME B16.5 – Pipe Flanges and Flanges Fittings, ASME B16.47 – Large Diameter Steel Flanges, or MSS SP-44 – Steel Pipeline Flanges. It is important to note that use of ASME flanges will likely require the use of special, nominal O.D. pipe that does not maintain the larger inside diameter of typical AWWA steel pipe.