2103-394 PTFE S/T BUP FDA

The TST394 is an AS568-394 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 24.94 in (633.48 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 25.36 in (644.14 mm). This back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

It resists solvents, strong acids and bases, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) is widely chosen for non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Verify compatibility before use with elemental fluorine at temperature or service requiring elastic recovery.

Typical settings include chemical processing, food and beverage, and laboratory equipment.

Reference part number TST394 when ordering; the item is sold individually. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.