2103-201 PTFE S/T BUP FDA

APG stocks the TST201, an AS568-201 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 0.171 in (4.34 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.449 in (11.4 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

As a material, PTFE (Teflon) is widely chosen for one of the lowest coefficients of friction of any solid and near-universal chemical inertness. The compound resists solvents, strong acids and bases, and steam. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Exposure to elemental fluorine at temperature or molten alkali metals will shorten service life.

Maintenance and OEM teams specify it across pharmaceutical and biotech, chemical processing, and aggressive-media pipelines.

Reference part number TST201 when ordering; the item is sold individually. Nominal inside diameter is listed as 3/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.