PTFE Valve Stem Packing Easily To Worn Valve Stems And Stuffing Boxes, Yet Forms A Very High-Density Packing When Compressed. Also, It Has Aging Resistance And A Low Coefficient Of Friction. Teflex PTFE Sealing Cord Can Be Used In A Wide Variety Of Applications, Including Mining And Minerals, Valves And Faucet Stems, Semiconductor Manufacturing, Rotating Shafts, Reciprocating Plungers,