2103-333 PTFE S/T BUP FDA

APG stocks the TST333, an AS568-333 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 2.475 in (62.87 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.895 in (73.53 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

It resists solvents, nearly all industrial chemicals, and strong acids and bases. That behavior comes from the compound itself: PTFE (Teflon) is known for non-stick, non-contaminating surface characteristics and excellent dielectric properties. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C).

Typical settings include chemical processing, semiconductor fabrication, and food and beverage.

Reference part number TST333 when ordering; the item is sold individually. Nominal inside diameter is listed as 2 1/2 inch. 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.