APG stocks the TST463, an AS568-463 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 16.955 in (430.66 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 17.505 in (444.63 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, nearly all industrial chemicals, and solvents. That behavior comes from the compound itself: PTFE (Teflon) is valued for excellent dielectric properties and one of the lowest coefficients of friction of any solid. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where elemental fluorine at temperature or service requiring elastic recovery are present.
It sees regular use in food and beverage, chemical processing, and laboratory equipment.
This item is sold individually under part number TST463. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 2103-463 PTFE S/T BUP FDA
Actual_CS 0.275 inch (6.99 mm)
Actual_ID 16.955 inch (430.66 mm)
Actual_OD 17.505 inch (444.63 mm)
ProductCode Description O-Rings - Backup Rings