This back-up ring is supplied in AS568-447 white PTFE (Teflon) 55 Shore D built to an inside diameter of 8.975 in (227.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 9.525 in (241.94 mm), catalogued under part number TST447SO. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
It resists steam, oxidizing media, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) is widely chosen for excellent dielectric properties and non-stick, non-contaminating surface characteristics. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C).
It sees regular use in chemical processing, food and beverage, and aggressive-media pipelines.
Stocked as TST447SO and sold individually. Nominal inside diameter is listed as 9 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.
Description 447 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 8.975 inch (227.97 mm)
Actual Outside Diameter 9.525 inch (241.94 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings