2103-441 PTFE S/T BUP FDA

TST441 is an AS568-441 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 6.975 in (177.17 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 7.525 in (191.14 mm). In service, this 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 valued for non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. It resists strong acids and bases, nearly all industrial chemicals, and steam. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C).

Maintenance and OEM teams specify it across laboratory equipment, chemical processing, and pharmaceutical and biotech.

Order part number TST441, sold individually. Nominal inside diameter is listed as 7 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.