391 PTFE SOLID BACKUP RING FDA

This back-up ring is supplied in AS568-391 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 21.953 in (557.61 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 22.373 in (568.27 mm), catalogued under part number TST391SO. 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. It resists steam, nearly all industrial chemicals, and oxidizing media. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Verify compatibility before use with elemental fluorine at temperature or service requiring elastic recovery.

Typical settings include aggressive-media pipelines, food and beverage, and pharmaceutical and biotech.

TST391SO ships individually. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.