237 PTFE SOLID BACKUP RING FDA

The TST237SO is an AS568-237 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 3.359 in (85.32 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.637 in (92.38 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.

PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and excellent dielectric properties. The compound resists solvents, steam, and strong acids and bases. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It is not the right choice where elemental fluorine at temperature or service requiring elastic recovery are present.

It sees regular use in aggressive-media pipelines, food and beverage, and laboratory equipment.

This item is sold individually under part number TST237SO. Nominal inside diameter is listed as 3 3/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.