This back-up ring is supplied in AS568-212 white PTFE (Teflon) 55 Shore D built to an inside diameter of 0.859 in (21.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.137 in (28.88 mm), catalogued under part number TST212SO. It bridges the extrusion gap so the primary seal holds its shape under load.
As a material, PTFE (Teflon) is specified for a very wide continuous service temperature range and excellent dielectric properties. Expect good resistance to nearly all industrial chemicals, strong acids and bases, and oxidizing media. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C).
Maintenance and OEM teams specify it across food and beverage, chemical processing, and semiconductor fabrication.
TST212SO ships individually. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Description 212 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 0.859 inch (21.82 mm)
Actual Outside Diameter 1.137 inch (28.88 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings