This back-up ring is supplied in AS568-212 white PTFE (Teflon) 55 Shore D built to an inside diameter of 0.859 in (21.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.137 in (28.88 mm), catalogued under part number TST212. It extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is specified here for one of the lowest coefficients of friction of any solid and near-universal chemical inertness. Expect good resistance to solvents, steam, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Exposure to service requiring elastic recovery or elemental fluorine at temperature will shorten service life.
Common environments for this compound include semiconductor fabrication, food and beverage, and chemical processing.
Order part number TST212, sold individually. Nominal inside diameter is listed as 7/8 inch. Check the compound against your process media, pressure and temperature before committing to a design.
Description 2103-212 PTFE S/T BUP FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 0.859 inch (21.82 mm)
Actual Outside Diameter 1.137 inch (28.88 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings