Ordered as TST262SO, this is an AS568-262 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 6.984 in (177.39 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 7.262 in (184.45 mm). The back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
PTFE (Teflon) is specified here for non-stick, non-contaminating surface characteristics and very wide continuous service temperature range. It resists oxidizing media, solvents, and strong acids and bases. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C).
You will find this material specified across semiconductor fabrication, laboratory equipment, and chemical processing.
Reference part number TST262SO when ordering; the item is sold individually. Nominal inside diameter is listed as 7 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Description 262 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 6.984 inch (177.39 mm)
Actual Outside Diameter 7.262 inch (184.45 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings