*166 PTFE SOLID BACKUP RING FDA

APG stocks the TST166SO, an AS568-166 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 6.737 in (171.12 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 6.943 in (176.35 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

As a material, PTFE (Teflon) is widely chosen for non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. Expect good resistance to strong acids and bases, oxidizing media, and solvents. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Exposure to service requiring elastic recovery or elemental fluorine at temperature will shorten service life.

You will find this material specified across semiconductor fabrication, chemical processing, and laboratory equipment.

Order part number TST166SO, sold individually. Nominal inside diameter is listed as 6 3/4 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.