Ordered as TST328SO, this is an AS568-328 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 1.85 in (46.99 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.27 in (57.66 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is specified here for very wide continuous service temperature range and near-universal chemical inertness. This material stands up to solvents, nearly all industrial chemicals, and strong acids and bases. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It is not the right choice where molten alkali metals or elemental fluorine at temperature are present.
Typical settings include laboratory equipment, pharmaceutical and biotech, and aggressive-media pipelines.
This item is sold individually under part number TST328SO. Nominal inside diameter is listed as 1 7/8 inch. Check the compound against your process media, pressure and temperature before committing to a design.
description 328 PTFE SOLID BACKUP RING FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 1.85 inch (46.99 mm)
Actual_OD 2.27 inch (57.66 mm)
ProductCode Description O-Rings - Backup Rings