238 PTFE SOLID BACKUP RING FDA

Part number TST238SO is an AS568-238 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 3.484 in (88.49 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.762 in (95.55 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, PTFE (Teflon) is known for excellent dielectric properties and near-universal chemical inertness. The material holds up against strong acids and bases, steam, and nearly all industrial chemicals. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Exposure to molten alkali metals or service requiring elastic recovery will shorten service life.

It sees regular use in food and beverage, chemical processing, and laboratory equipment.

This item is sold individually under part number TST238SO. Check the compound against your process media, pressure and temperature before committing to a design.