GRE Isolating Gaskets are used for controlling losses due to corrosion. They can be used to control stray electric currents in piping at oil, gas, water, refinery, and chemical plants, to increase the effectiveness of cathodic protection systems.
Type E (full face) insulating gasket provides complete protection of both flange faces. The gasket has same outside diameter of flanges. This feature will prevent collection of foreign matter between the flange faces to ensure complete cathodic isolation.
Type F (ring gasket) insulating gasket is manufactured to fit only the raised face surface of the flanges. Outside diameter of the gasket is designed to be slightly less than the inside diameter of the bolt circle. It is recommended that the flanges be wrapped to prevent foreign material from "shorting out" the flanges.
Type D Gaskets are available for RTJ flanges, the common material is phenolic and GRE.
GRE Isolating Gaskets are used for sealing and isolating the flanges, which are utilized for preventing the flanges from corrosion.