442 PTFE SOLID BACKUP RING FDA

APG stocks the TST442SO, an AS568-442 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 7.225 in (183.52 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 7.775 in (197.49 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, PTFE (Teflon) delivers excellent dielectric properties and a very wide continuous service temperature range. The compound resists oxidizing media, steam, and solvents. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Exposure to molten alkali metals or service requiring elastic recovery will shorten service life.

Typical settings include pharmaceutical and biotech, laboratory equipment, and semiconductor fabrication.

TST442SO ships individually. Nominal inside diameter is listed as 7 1/4 inch. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.