This specification covers various types, classes, and grades of flexible graphite material in which valve media temperatures are limited to a maximum temperature. The material shall be classified into two types, classes, and grades. Type I is a corrugated ribbon or textured tape, Type II is die-formed ring. Class 1 is for use where detrimental material content of the packing need not be controlled beyond normal manufacturing limit and Class 2 is for use where detrimental material content must be controlled to the limits specified herein. Grade A is treated with corrosion inhibitor and Grade B not treated with corrosion inhibitor. Different tests and measurements shall be conducted in order to determine the following properties: size, bulk density, ash content, and graphite purity.