Ordered as TST013, this is an AS568-013 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 0.426 in (10.82 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.566 in (14.38 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
PTFE (Teflon) is specified here for one of the lowest coefficients of friction of any solid and very wide continuous service temperature range. The compound resists strong acids and bases, solvents, and steam. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Applications involving molten alkali metals or elemental fluorine at temperature call for a different compound.
Maintenance and OEM teams specify it across laboratory equipment, aggressive-media pipelines, and chemical processing.
Stocked as TST013 and sold individually. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Description 2103-013 PTFE S/T BUP FDA
Actual Cross Section 0.07 inch (1.78 mm)
Actual Inside Diameter 0.426 inch (10.82 mm)
Actual Outside Diameter 0.566 inch (14.38 )
Measurement System Imperial
Product Category O-Rings - Backup Rings