This back-up ring is supplied in AS568-128 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 1.487 in (37.77 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.693 in (43 mm), catalogued under part number TST128SO. It allows a standard o-ring to operate at higher pressures than it could unsupported.
It resists steam, solvents, and oxidizing media. That behavior comes from the compound itself: PTFE (Teflon) is specified for non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where service requiring elastic recovery or molten alkali metals are present.
Maintenance and OEM teams specify it across food and beverage, aggressive-media pipelines, and chemical processing.
Stocked as TST128SO and sold individually. Nominal inside diameter is listed as 1 1/2 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.
Description 128 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 1.487 inch (37.77 mm)
Actual Outside Diameter 1.693 inch (43 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings