249 PTFE SOLID BACKUP RING FDA

APG stocks the TST249SO, an AS568-249 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 4.859 in (123.42 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.137 in (130.48 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

PTFE (Teflon) delivers near-universal chemical inertness and non-stick, non-contaminating surface characteristics. The compound resists nearly all industrial chemicals, solvents, and oxidizing media. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in elemental fluorine at temperature or service requiring elastic recovery.

Maintenance and OEM teams specify it across chemical processing, aggressive-media pipelines, and semiconductor fabrication.

TST249SO ships individually. As always, verify media compatibility and operating conditions against the requirements of your specific application.