*PTFE SOLID BACK UP -429 WHT FDA

This back-up ring is supplied in AS568-429 white PTFE (Teflon) 55 Shore D built to an inside diameter of 4.975 in (126.37 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.525 in (140.34 mm), catalogued under part number TST429SO. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

PTFE (Teflon) is specified here for near-universal chemical inertness and very wide continuous service temperature range. The compound resists nearly all industrial chemicals, oxidizing media, and strong acids and bases. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Verify compatibility before use with service requiring elastic recovery or elemental fluorine at temperature.

Common environments for this compound include pharmaceutical and biotech, semiconductor fabrication, and aggressive-media pipelines.

TST429SO ships individually. Nominal inside diameter is listed as 5 inch. Check the compound against your process media, pressure and temperature before committing to a design. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.