2103-435 PTFE S/T BUP FDA

APG stocks the TST435, an AS568-435 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 5.725 in (145.42 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 6.275 in (159.39 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

The compound resists steam, strong acids and bases, and oxidizing media. That behavior comes from the compound itself: PTFE (Teflon) is valued for one of the lowest coefficients of friction of any solid and near-universal chemical inertness. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Verify compatibility before use with service requiring elastic recovery or molten alkali metals.

You will find this material specified across aggressive-media pipelines, pharmaceutical and biotech, and laboratory equipment.

Reference part number TST435 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 3/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.