The TST236SO is an AS568-236 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 3.234 in (82.14 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.512 in (89.2 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
PTFE (Teflon) is specified here for very wide continuous service temperature range and near-universal chemical inertness. The compound resists strong acids and bases, oxidizing media, and steam. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Applications involving service requiring elastic recovery or molten alkali metals call for a different compound.
You will find this material specified across semiconductor fabrication, food and beverage, and chemical processing.
Order part number TST236SO, sold individually. Nominal inside diameter is listed as 3 1/4 inch. 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 236 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 3.234 inch (82.14 mm)
Actual Outside Diameter 3.512 inch (89.2 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings