Metal gaskets are fabricated out of metal, and the most common type are the ring joint gasket (RTJ gasket) that are used in connection with RTJ flanges. Ring type joint gaskets create a seal when a bolting force is applied to the flange and the softer material of the gaskets gets “squeezed” into the micro fine structure of the flange (which is made of a harder material) creating a very tight and lasting metal to metal seal (or metal to metal connection). Ring type gaskets were developed to ensure lasting and strong seals for flanges, valves, piping spools and vessels at high pressure and temperature conditions (typical of the petrochemical industry).

The most common type of RTJ gaskets is the “style R”, which is machined to tight manufacturing tolerances to ensure correct installation with standard ASME B16.5 and API 6B ring joint faced flanges. The material of RTJ gaskets shall match the flanges material but is shall have a lower hardness than the material of the flanges: this to ensure that the gasket, and not the flange, gets plastically deformed within the groove of the flange as a bolting pressure is applied to the flanges. “R style” oval and octagonal RTJ gaskets can seal pressures up to 6.250 psi by ASME B16.20 and up to 5.000 psi according to the API 6A pressure ratings. RTJ type is frequently used as valve cover gasket. Besides the “R style” ring joint gaskets, the other two popular designs are the “Style BX” and “Style RX” RTJ gaskets.


Ring joint gaskets



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