Part number TST449 is an AS568-449 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 9.975 in (253.37 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 10.525 in (267.34 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 non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. It resists steam, strong acids and bases, and nearly all industrial chemicals. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Applications involving service requiring elastic recovery or elemental fluorine at temperature call for a different compound.
Common environments for this compound include laboratory equipment, food and beverage, and semiconductor fabrication.
Reference part number TST449 when ordering; the item is sold individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 2103-449 PTFE S/T BUP FDA
Actual_CS 0.275 inch (6.99 mm)
Actual_ID 9.975 inch (253.37 mm)
Actual_OD 10.525 inch (267.34 mm)
ProductCode Description O-Rings - Backup Rings