2103-139 PTFE S/T BUP FDA

Ordered as TST139, this is an AS568-139 white PTFE (Teflon) 55 Shore D Back-Up Ring built to 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). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

It resists oxidizing media, strong acids and bases, and steam. PTFE (Teflon) delivers a very wide continuous service temperature range and one of the lowest coefficients of friction of any solid. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Exposure to service requiring elastic recovery or molten alkali metals will shorten service life.

Maintenance and OEM teams specify it across chemical processing, semiconductor fabrication, and laboratory equipment.

This item is sold individually under part number TST139. Review your operating media and conditions against this specification before installation.