2103-040 PTFE S/T BUP FDA

Part number TST040 is an AS568-040 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 2.864 in (72.75 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 3.004 in (76.3 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, PTFE (Teflon) is known for one of the lowest coefficients of friction of any solid and excellent dielectric properties. The material holds up against oxidizing media, nearly all industrial chemicals, and strong acids and bases. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where molten alkali metals or elemental fluorine at temperature are present.

Typical settings include chemical processing, semiconductor fabrication, and laboratory equipment.

TST040 ships individually. Nominal inside diameter is listed as 2 7/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. 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.