This back-up ring is supplied in AS568-221 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 1.421 in (36.09 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.699 in (43.15 mm), catalogued under part number TST221. It extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is known for near-universal chemical inertness and one of the lowest coefficients of friction of any solid. It 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.
It sees regular use in pharmaceutical and biotech, aggressive-media pipelines, and laboratory equipment.
Order part number TST221, sold individually. Unit weight is approximately 0.0033 lb. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 1.421 inch (36.09 mm)
Actual_OD 1.699 inch (43.15 mm)
ProductCode Description O-Rings - Backup Rings