R-Type Oval Ring Gasket Manufacturer: R-Type Oval Ring Gaskets, SS316, PN250, 1500LB Pressure, 4 Inch (DN100) Size, R=39, ASME B16.20 Standard. Type: Oval Ring Gasket. R=39, R-Type. Material: SS316. Size: 4 Inch (DN100). Pressure: 1500LB (PN250). Standard: ASME B16.20.