149 PTFE SOLID BACKUP RING FDA

Part number TST149SO is an AS568-149 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 2.8 in (71.12 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 3.006 in (76.35 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

It resists steam, strong acids and bases, and solvents. That behavior comes from the compound itself: PTFE (Teflon) is specified for near-universal chemical inertness and one of the lowest coefficients of friction of any solid. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Verify compatibility before use with elemental fluorine at temperature or service requiring elastic recovery.

You will find this material specified across chemical processing, laboratory equipment, and aggressive-media pipelines.

Order part number TST149SO, sold individually. Nominal inside diameter is listed as 2 13/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. 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.