1.1 ,This specification covers staple or continuous filament carbon/graphite yarn valve stem compression packing, suitable for use as end-rings on packing systems for valves. Intended services include steam, hydrocarbons, water, and non-oxidizing chemicals. Where this specification is invoked as ASTM F2191/F2191M, Sections 1 –, 18 apply. Where this specification is invoked as ASTM/DoD F2191/F2191M, Sections 1 –, 18 and the Supplementary Requirements shall be applicable.