The R-Type ring gasket can be ordered to two different profiles, oval or octagonal in cross-sections. Both types have identical pitch diameter as the flange groove they correspond to. These gaskets are used in pressures up to 5,000 PSI. The octagonal type has a higher sealing coeffient than the oval, therefore being the better gasket of the two. The oval type is the only gasket that will fit a bottom radiused groove. Flanges with flat bottom v-grooves will accept either style. Gaskets that have been torqued initiating a metal-to-metal seal should be discarded and not reused.
The oval section ring gaskets were originally designed for the now obsolete round bottom groove. Both the Oval and the Octagonal cross section are interchangeable on the flat bottom groove design. These gaskets are manufactured as per API 6A / ASME B16.20 to suit API 6B and ASME B16.50 flanges.
Surface finish of the Style R Ring Type Joint sealing faces (…