*109 PTFE SOLID BACKUP RING FDA

This back-up ring is supplied in AS568-109 white PTFE (Teflon) 55 Shore D supplied with an inside diameter of 0.299 in (7.59 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 0.505 in (12.83 mm), catalogued under part number TST109SO. It allows a standard o-ring to operate at higher pressures than it could unsupported.

PTFE (Teflon) is specified here for near-universal chemical inertness and excellent dielectric properties. This material stands up to steam, nearly all industrial chemicals, and solvents. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C).

Maintenance and OEM teams specify it across semiconductor fabrication, food and beverage, and laboratory equipment.

Order part number TST109SO, sold individually. Nominal inside diameter is listed as 5/16 inch. Check the compound against your process media, pressure and temperature before committing to a design.