APG stocks the TST224SO, an AS568-224 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.734 in (44.04 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 2.012 in (51.1 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.
It resists solvents, nearly all industrial chemicals, and strong acids and bases. PTFE (Teflon) delivers one of the lowest coefficients of friction of any solid and near-universal chemical inertness. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It should not be specified for service in service requiring elastic recovery or elemental fluorine at temperature.
Maintenance and OEM teams specify it across semiconductor fabrication, chemical processing, and laboratory equipment.
TST224SO ships individually. Check the compound against your process media, pressure and temperature before committing to a design. 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.
Description 224 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 1.734 inch (44.04 mm)
Actual Outside Diameter 2.012 inch (51.1 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings