2103-248 PTFE S/T BUP FDA

This back-up ring is supplied in AS568-248 white PTFE (Teflon) 55 Shore D supplied with an inside diameter of 4.734 in (120.24 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.012 in (127.3 mm), catalogued under part number TST248. It bridges the extrusion gap so the primary seal holds its shape under load.

PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. The material holds up against solvents, nearly all industrial chemicals, and steam. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in service requiring elastic recovery or elemental fluorine at temperature.

You will find this material specified across food and beverage, laboratory equipment, and semiconductor fabrication.

Order part number TST248, sold individually. Nominal inside diameter is listed as 4 3/4 inch. Check the compound against your process media, pressure and temperature before committing to a design. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.