438 PTFE SOLID BACKUP RING FDA

Part number TST438SO is an AS568-438 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 6.225 in (158.12 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 6.775 in (172.09 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

PTFE (Teflon) is specified here for excellent dielectric properties and very wide continuous service temperature range. It resists solvents, strong acids and bases, 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 service requiring elastic recovery or molten alkali metals.

Typical settings include aggressive-media pipelines, chemical processing, and semiconductor fabrication.

Stocked as TST438SO and sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.