427 PTFE SOLID BACKUP RING FDA

The TST427SO is an AS568-427 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 4.725 in (120.02 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.275 in (133.99 mm). This back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

It resists strong acids and bases, solvents, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) offers 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).

Common environments for this compound include chemical processing, aggressive-media pipelines, and laboratory equipment.

Stocked as TST427SO and sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.