439 PTFE SOLID BACKUP RING FDA

This back-up ring is supplied in AS568-439 white PTFE (Teflon) 55 Shore D built to an inside diameter of 6.475 in (164.47 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 7.025 in (178.44 mm), catalogued under part number TST439SO. It allows a standard o-ring to operate at higher pressures than it could unsupported.

As a material, PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and excellent dielectric properties. This material stands up to strong acids and bases, steam, and nearly all industrial chemicals. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in service requiring elastic recovery or molten alkali metals.

You will find this material specified across pharmaceutical and biotech, aggressive-media pipelines, and chemical processing.

Stocked as TST439SO and sold individually. Nominal inside diameter is listed as 6 1/2 inch. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.