2107-257 PTFE SPIRAL B/U FDA

Ordered as TSP257, this is an AS568-257 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 5.859 in (148.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.137 in (155.88 mm). The back-up ring 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 excellent dielectric properties. The compound resists solvents, oxidizing media, and steam. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Verify compatibility before use with elemental fluorine at temperature or service requiring elastic recovery.

Maintenance and OEM teams specify it across laboratory equipment, chemical processing, and food and beverage.

Stocked as TSP257 and sold individually. Nominal inside diameter is listed as 5 7/8 inch. Review your operating media and conditions against this specification before installation.