by Fluid Sealing Association
December 17, 2011

Blended synthetic and fiberglass yarns can be coated with PTFE to produce economical, general service packings that exhibit higher resilience, greater extrusion resistance, and less sensitivity to adjustment than a PTFE fiber braid. They can also be coated with a dispersion mixture of PTFE and graphite to further increase the speed capability and heat dissipation characteristics of the braid.

Aramid fiber packings with a PTFE coating can be used in applications requiring extreme abrasion resistance. Novoloid fiber packings with PTFE coatings can be used in mild caustic services, and also exhibit better resilience and extrusion resistance than a PTFE fiber braid.

Carbon and graphite fiber braids with PTFE coatings are among the most versatile packing materials. They have excellent chemical resistance (with the exception of strong oxidizers), high speed capability, high temperature capability, and very good resilience. They are not prone to softening or extrusion at high temperature, and also exhibit good abrasion resistance. 

By understanding the strengths and limitations of the various forms of braided PTFE packing, you can choose a product that will most effectively meet the pump or valve sealing demands of a process.

 

We invite your questions on sealing issues and will provide best efforts answers based on FSA publications. 

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