This back-up ring is supplied in AS568-353 white PTFE (Teflon) 55 Shore D built to an inside diameter of 4.975 in (126.37 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.395 in (137.03 mm), catalogued under part number TST353SO. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
It resists steam, oxidizing media, and strong acids and bases. PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics 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). Verify compatibility before use with molten alkali metals or elemental fluorine at temperature.
You will find this material specified across food and beverage, aggressive-media pipelines, and pharmaceutical and biotech.
Order part number TST353SO, sold individually. Nominal inside diameter is listed as 5 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description 353 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 4.975 inch (126.37 mm)
Actual Outside Diameter 5.395 inch (137.03 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings