Ordered as TST018SO, this is an AS568-018 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 0.739 in (18.77 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.879 in (22.33 mm). The 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 valued for excellent dielectric properties and one of the lowest coefficients of friction of any solid. This material stands up to strong acids and bases, steam, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Verify compatibility before use with elemental fluorine at temperature or molten alkali metals.
Typical settings include pharmaceutical and biotech, chemical processing, and laboratory equipment.
Order part number TST018SO, sold individually. Nominal inside diameter is listed as 3/4 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description *018 PTFE SOLID BACKUP RING FDA
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 0.739 inch (18.77 mm)
Actual_OD 0.879 inch (22.33 mm)
ProductCode Description O-Rings - Backup Rings