NON-METALLIC GASKETS are usually composite sheet materials are used with flat-face and raised-face flanges in low Pressure Class applications. Non-metallic gaskets are manufactured from arimid fiber, glass fiber, elastomer, Teflon® (PTFE), graphite etc.. Full-face gasket types are suitable for use with flat-face flanges. Flat-ring gasket types are suitable for use with raised face flanges.

ASME B16.21 covers types, sizes, materials, dimensions, dimensional tolerances, and markings for non-metallic flat gaskets.

Usually composite sheet materials are used with and low pressure class applications. Non-metallic gaskets are manufactured non-asbestos material or Compressed Asbestos Fibre (CAF). Non-asbestos types include arimid fibre, glass fibre,
elastomer, Teflon (PTFE) and flexible graphite. PTFE or RPTFE are used in high corrosive applications.

Full face gasket types are suitable for use with flat-face (FF) flanges and flat-ring gasket types are suitable