2103-209 PTFE S/T BUP FDA

TST209 is an AS568-209 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 0.671 in (17.04 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.949 in (24.1 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

It resists solvents, steam, and strong acids and bases. PTFE (Teflon) offers near-universal chemical inertness and one of the lowest coefficients of friction of any solid. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It is not the right choice where molten alkali metals or service requiring elastic recovery are present.

Maintenance and OEM teams specify it across aggressive-media pipelines, semiconductor fabrication, and food and beverage.

Stocked as TST209 and sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.