Ring Gaskets

Ring gaskets also known as RTJ, used in offshore oil and gas pipelines and are designed to work under extremely high pressure. They are solid rings of metal in different cross sections like oval, round, octagonal etc. Also, they come with hole in center for pressure equalization.
There are three types of Ring Gaskets. Type R & Type RX which are used on 6B flanges and BX Gaskets are used on 6BX Flanges. Ring gaskets are made of different materials like Soft Iron, Carbon and low alloy steel, 304 stainless steel, 316 stainless steel, Nickel alloy UNS N08825 & Other CRA materials. 
Ring gaskets are marked at the OD of gasket for date of manufacture, Manufactures name (Reliable Valves), gasket type & number and Material.