*2107-139 PTFE SPIRAL B/U FDA

APG stocks the TSP139, an AS568-139 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 2.175 in (55.25 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.381 in (60.48 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

PTFE (Teflon) is specified here for one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. Expect good resistance to strong acids and bases, oxidizing media, and solvents. Continuous operating temperature is published at -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 laboratory equipment, pharmaceutical and biotech, and semiconductor fabrication.

TSP139 ships individually. Nominal inside diameter is listed as 2 3/16 inch. Check the compound against your process media, pressure and temperature before committing to a design.