*228 PTFE SOLID BACKUP RING FDA

The TST228SO is an AS568-228 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 2.234 in (56.74 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 2.512 in (63.8 mm). This back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

PTFE (Teflon) is specified here for non-stick, non-contaminating surface characteristics and near-universal chemical inertness. Expect good resistance to strong acids and bases, solvents, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Applications involving molten alkali metals or service requiring elastic recovery call for a different compound.

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

Stocked as TST228SO and sold individually. Nominal inside diameter is listed as 2 1/4 inch. Review your operating media and conditions against this specification before installation. 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.