2103-121 PTFE S/T BUP FDA

Ordered as TST121, this is an AS568-121 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.049 in (26.64 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.255 in (31.88 mm). The back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

PTFE (Teflon) is specified here for very wide continuous service temperature range and non-stick, non-contaminating surface characteristics. This material stands up to solvents, steam, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It should not be specified for service in service requiring elastic recovery or molten alkali metals.

Common environments for this compound include aggressive-media pipelines, pharmaceutical and biotech, and semiconductor fabrication.

Reference part number TST121 when ordering; the item is sold individually. Nominal inside diameter is listed as 1 1/16 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.