Part number TST208SO is an AS568-208 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 0.609 in (15.47 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.887 in (22.53 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) offers non-stick, non-contaminating surface characteristics and near-universal chemical inertness. The compound resists solvents, nearly all industrial chemicals, and oxidizing media. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It should not be specified for service in service requiring elastic recovery or molten alkali metals.
Typical settings include semiconductor fabrication, aggressive-media pipelines, and chemical processing.
This item is sold individually under part number TST208SO. 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.
Description 208 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 0.609 inch (15.47 mm)
Actual Outside Diameter 0.887 inch (22.53 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings