2103-266 PTFE S/T BUP FDA

TST266 is an AS568-266 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 7.984 in (202.79 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 8.262 in (209.85 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, PTFE (Teflon) delivers one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. Expect good resistance to steam, strong acids and bases, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It should not be specified for service in service requiring elastic recovery or elemental fluorine at temperature.

You will find this material specified across semiconductor fabrication, laboratory equipment, and chemical processing.

Reference part number TST266 when ordering; the item is sold individually. Nominal inside diameter is listed as 8 inch. Check the compound against your process media, pressure and temperature before committing to a design. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.