... 2.Shape:octagonal,oval,lens 3.Size:R11-105,RX20-215,BX150-303,Inch1/2"-24" Ring joint gasket (RTJ ... B16.20 and API 6A used on the ring type joint flanges specified in JPI-7S-15, ANSI B16.5 ... employed where corrosive agents are present. These gaskets are designed in oval/octagonal shapes confirming to R,Bx and Rx series ... std 6A. 1.Type :R.BX.RX 2.Shape:octagonal,oval,lens3.Size:R11-105,RX20-215,BX150-303, ...