APG stocks the TST280, an AS568-280 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 13.984 in (355.19 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 14.262 in (362.25 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
PTFE (Teflon) is specified here for very wide continuous service temperature range and one of the lowest coefficients of friction of any solid. The material holds up against strong acids and bases, solvents, and steam. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Applications involving molten alkali metals or elemental fluorine at temperature call for a different compound.
You will find this material specified across aggressive-media pipelines, food and beverage, and chemical processing.
This item is sold individually under part number TST280. Check the compound against your process media, pressure and temperature before committing to a design.
description 2103-280 PTFE S/T BUP FDA
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 13.984 inch (355.19 mm)
Actual_OD 14.262 inch (362.25 mm)
ProductCode Description O-Rings - Backup Rings