The R-Type ring gasket are available in Ring numbers from 11 to 105 & can be ordered in two different profiles, oval or octagonal . Both types have an identical pitch diameter as the flange groove they correspond to. These gaskets are used in pressures up to 5,000 PSI in API 6B flanges, and up to 2,500 PSI in ASME/ANSI B16.5 flanges. The oval type is the only gasket that will fit a round bottom groove. Flanges with flat bottom v-grooves will accept either oval or octagonal.