This back-up ring is supplied in AS568-038 white PTFE (Teflon) 55 Shore D built to an inside diameter of 2.614 in (66.4 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 2.754 in (69.95 mm), catalogued under part number TST038. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
The compound resists strong acids and bases, steam, and oxidizing media. PTFE (Teflon) offers excellent dielectric properties and non-stick, non-contaminating surface characteristics. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service.
Typical settings include pharmaceutical and biotech, laboratory equipment, and chemical processing.
Order part number TST038, sold individually. Nominal inside diameter is listed as 2 5/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 2103-038 PTFE S/T BUP FDA
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 2.614 inch (66.4 mm)
Actual_OD 2.754 inch (69.95 mm)
ProductCode Description O-Rings - Backup Rings