Ring Joint Gaskets

Ring type Joint is a method of ensuring leak proof flange connection at high pressures. A metal ring is compressed into a hexagonal groove on the face of the flange to make the seal.

       

RING GROOVE IN 6 B FLANGES
R ring gaskets come in oval and octagonal configurations. R ring gaskets have the same nominal pitch diameter as the groove into which they fit. When placing a new r ring gasket into a new or like new ring groove the gasket should contact or nearly contact on both o.d. and i.d. coining occurs on both o.d. and i.d. during make-up.

"R" RING GROOVE WITH RX GASKET
Rx gaskets have a pitch diameter slightly greater than the pitch diameter of the respective groove they fit. New rx gaskets placed in corresponding new ring grooves will usually contact on the o.d. and fit loosely on the i.d. rx gaskets have a design that produces coining only on the o.d. the gasket has a larger bearing surface on the i.d. producing an extreme load on the o.d. of the gasket to enhance coining and intimate contact on the o.d. surface pulling mating rx flanges together by tightening the bolts will compress the gasket, reducing its o.d. in conformance with the groove. The gasket finally meeting metal to metal on the i.d., the gasket compressed both vertically and in diameter.

RING GROOVE IN 6 BX FLANGES
Bx gaskets have a pitch diameter greater than the pitch diameter of the respective groove they fit. New bx gaskets placed in corresponding new ring grooves will always contact on the o.d. and fit loosely on the i.d. pulling mating bx flanges together by tightening the bolts will compress the gasket, reducing its o.d. in conformance with the groove. The gasket finally meeting metal to metal on the i.d., the gasket compressed both vertically and in diameter.
when flanges have been pulled together and bolts tightened to proper torque, ring gaskets experience "coining." coining forms the gasket to the exact finish and form of the sealing ring groove surfaces. Intimate contact of the coined ring gasket with the groove sealing surface, forms a seal to contain the fluid or gas inside the connection.
radial compression on the outside diameter of the ring gasket will maintain metal to metal contact on the o.d. should pressure cause some strain (stretching) on the connecting bolts.