Ordered as TST326, this is an AS568-326 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 1.6 in (40.64 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.02 in (51.31 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
PTFE (Teflon) is specified here for one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. The material holds up against strong acids and bases, steam, and nearly all industrial chemicals. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It is not the right choice where elemental fluorine at temperature or service requiring elastic recovery are present.
It sees regular use in semiconductor fabrication, pharmaceutical and biotech, and chemical processing.
Order part number TST326, sold individually. Nominal inside diameter is listed as 1 5/8 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 2103-326 PTFE S/T BUP FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 1.6 inch (40.64 mm)
Actual_OD 2.02 inch (51.31 mm)
ProductCode Description O-Rings - Backup Rings