Carbon Steel Standard Ring Flanges

We can split Carbon steel AWWA C207 Standard flanges in to two types of AWWA flanges i.e. Carbon steel AWWA C207 Standard Ring Flanged connections and Carbon steel AWWA C207 Standard Hub Flanged connections. These carbon steel flanges have been used in low pressure pipe line applications since a long time back and were required for the installation of flanged appurtenances, like carbon steel valves in the pipe line. These carbon steel ring or hub flanges were not manufactured to any particular standard and were riveted to the pipe barrel in those early days. As the use of low pressure steel pipe line works increased gradually, by the time the need for standardization of carbon steel low pressure ring flanges increased. Prior to 1950, these all carbon steel low pressure flanges were designed according to ASME specifications.

Carbon steel flanges complying with these ASME standards were manufactured to dimensions that can have a minimum pressure rating of 275 psi, which is in excess of pressure requirements needed for low pressure pipe line applications. In 1945, the ASME and the AWWA established a committee to develop a standard for these low pressure steel flanges for use in the piping industry that were compatible with the pressures, temperatures and dimensions normally encountered in supply piping systems.

During the latest revision to AWWA C207, and during the development of AWWA Standard C228, questions were presented relative to the design basis for AWWA carbon steel ring flanges. The discussions presented during this revision period focused on dimensional, primarily flange thickness, differences between AWWA and ASME carbon steel ring flanges. The pipe wall thickness is a critical component relative to carbon steel flange stresses.