**2103-320 PTFE S/T BUP FDA

This back-up ring is supplied in AS568-320 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 1.1 in (27.94 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.52 in (38.61 mm), catalogued under part number TST320. It bridges the extrusion gap so the primary seal holds its shape under load.

As a material, PTFE (Teflon) offers near-universal chemical inertness and one of the lowest coefficients of friction of any solid. The material holds up against nearly all industrial chemicals, solvents, and steam. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It should not be specified for service in service requiring elastic recovery or molten alkali metals.

Maintenance and OEM teams specify it across chemical processing, aggressive-media pipelines, and semiconductor fabrication.

Reference part number TST320 when ordering; the item is sold individually. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.