356 PTFE SOLID BACKUP RING FDA

Ordered as TST356SO, this is an AS568-356 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 5.35 in (135.89 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.77 in (146.56 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

PTFE (Teflon) is specified here for non-stick, non-contaminating surface characteristics and excellent dielectric properties. This material stands up to oxidizing media, strong acids and bases, and solvents. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). Applications involving elemental fluorine at temperature or service requiring elastic recovery call for a different compound.

Maintenance and OEM teams specify it across aggressive-media pipelines, semiconductor fabrication, and pharmaceutical and biotech.

Stocked as TST356SO and sold individually. Nominal inside diameter is listed as 5 3/8 inch. 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.