Ring Type Gasket

The solid metal gasket provides an excellent mechanical joint and has almost universal acceptance in the oil, petroleum and chemical processing industries where high mechanical and thermal performance is required. The type R oval configuration is the original ring joint design and was followed by the type R octagonal which offered more specific sealing contact areas. Details of these joints are given in ASME B 16.20 and API 6A standards. The gaskets sit in a recess in the flange face having 23° angled walls. The RX joints are an unequal bevel octagonal ring, and are considered to be a pressure energized or pressure-assisted seal. The BX is also octagonal, though shorter in profile and designed to go into a recess that comes metal-to-metal when the flanges are tightened. These are used on very high pressure flanges up to 20,000 p.s.i. rating. Gasket metal should be selected to suit the service conditions and should have hardness lower than the flange metal.