The PTC Compact Seal is a double acting piston seal consisting of a TRIALON® (fi lled or unfi lled PTFE) element, performing the main sealing function and energized by an elastomer in TRIAFLEX® (NBR material), supported by two slit TRIAMIDE® Back-Up Rings, which positions the Piston centrally within the Cylinder bore. These TRIAMIDE® Back-Up Rings limits the extrusion of the Sealing Element and thus enhances the life of the seal.