2103-358 PTFE S/T BUP FDA

Part number TST358 is an AS568-358 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 5.6 in (142.24 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 6.02 in (152.91 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

The material holds up against oxidizing media, steam, and nearly all industrial chemicals. PTFE (Teflon) offers near-universal chemical inertness and non-stick, non-contaminating surface characteristics. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C).

Maintenance and OEM teams specify it across laboratory equipment, food and beverage, and chemical processing.

Stocked as TST358 and 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.