This back-up ring is supplied in AS568-321 white PTFE (Teflon) 55 Shore D with an inside diameter of 1.162 in (29.51 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.582 in (40.18 mm), catalogued under part number TST321. It bridges the extrusion gap so the primary seal holds its shape under load.
It resists nearly all industrial chemicals, oxidizing media, and steam. PTFE (Teflon) offers 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 pharmaceutical and biotech, aggressive-media pipelines, and semiconductor fabrication.
Order part number TST321, sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description 2103-321 PTFE S/T BUP FDA
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 1.162 inch (29.51 mm)
Actual Outside Diameter 1.582 inch (40.18 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings