Flexible Graphite

Flexible Graphite - produced from natural graphite - has a Carbon content from 90% to 99.9%. Graphite flakes are treated with acid, neutralized and dried. The flakes are then subjected to high temperature, and the water, after vaporizing, “blow- up” the flakes, which increase up to 200 times or more of their original volume. Those expanded flakes are calendared without any additive or binder, producing sheets of high flexibility and excellent thermal resistance. Gaskets made from flexible graphite show low creep values, defined as continuous plastic deformation when subjected to pressure. Therefore, there is only a small loss of bolt load, which reduces the need for retightening of the bolts.
Principal Characteristics of Flexible Graphite:
Due to its characteristics, flexible graphite is one of the most reliable sealing materials. It offers excellent resistance to acids, alkaline solutions and organic composites. However, it is not recommended for use in service with oxidants at temperatures above 450ºC (840ºF). The heated Carbon reacts with oxygen forming Carbon Dioxide (CO2). The result of this reaction is the reduction of gasket mass and consequently of bolt load.