2103-318 PTFE S/T BUP FDA

This back-up ring is supplied in AS568-318 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 0.975 in (24.77 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.395 in (35.43 mm), catalogued under part number TST318. It 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 non-stick, non-contaminating surface characteristics and near-universal chemical inertness. It resists solvents, oxidizing media, and strong acids and bases. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). Applications involving molten alkali metals or service requiring elastic recovery call for a different compound.

It sees regular use in pharmaceutical and biotech, semiconductor fabrication, and food and beverage.

This item is sold individually under part number TST318. As always, verify media compatibility and operating conditions against the requirements of your specific application. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.