233 PTFE SOLID BACKUP RING FDA

TST233SO is an AS568-233 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 2.859 in (72.62 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.137 in (79.68 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

The compound resists solvents, oxidizing media, and strong acids and bases. That behavior comes from the compound itself: PTFE (Teflon) is valued for a very wide continuous service temperature range 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.

Maintenance and OEM teams specify it across aggressive-media pipelines, laboratory equipment, and semiconductor fabrication.

This item is sold individually under part number TST233SO. 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.