TST464 is an AS568-464 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 17.455 in (443.36 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 18.005 in (457.33 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
PTFE (Teflon) is specified here for one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. This material stands up to nearly all industrial chemicals, strong acids and bases, and oxidizing media. 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 molten alkali metals are present.
Typical settings include pharmaceutical and biotech, food and beverage, and semiconductor fabrication.
TST464 ships individually. Nominal inside diameter is listed as 17 1/2 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 2103-464 PTFE S/T BUP FDA
Actual_CS 0.275 inch (6.99 mm)
Actual_ID 17.455 inch (443.36 mm)
Actual_OD 18.005 inch (457.33 mm)
ProductCode Description O-Rings - Backup Rings