*329 PTFE SOLID BACKUP RING FDA

The TST329SO is an AS568-329 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.975 in (50.17 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.395 in (60.83 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 excellent dielectric properties. It resists nearly all industrial chemicals, oxidizing media, and strong acids and bases. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Applications involving elemental fluorine at temperature or service requiring elastic recovery call for a different compound.

Maintenance and OEM teams specify it across laboratory equipment, chemical processing, and food and beverage.

Stocked as TST329SO and sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.