**217 PTFE SOLID BACKUP RING FDA

This back-up ring is supplied in AS568-217 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 1.171 in (29.74 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.449 in (36.8 mm), catalogued under part number TST217SO. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

It resists nearly all industrial chemicals, strong acids and bases, and steam. PTFE (Teflon) is widely chosen for excellent dielectric properties and a very wide continuous service temperature range. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service.

It sees regular use in aggressive-media pipelines, chemical processing, and semiconductor fabrication.

Reference part number TST217SO when ordering; the item is sold individually. Nominal inside diameter is listed as 1 3/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.