Ordered as TST364, this is an AS568-364 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 6.725 in (170.82 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 7.145 in (181.48 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
PTFE (Teflon) is specified here for very wide continuous service temperature range and near-universal chemical inertness. It resists strong acids and bases, solvents, and nearly all industrial chemicals. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Exposure to elemental fluorine at temperature or molten alkali metals will shorten service life.
Typical settings include laboratory equipment, food and beverage, and chemical processing.
TST364 ships individually. Nominal inside diameter is listed as 6 3/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 2103-364 PTFE S/T BUP FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 6.725 inch (170.82 mm)
Actual_OD 7.145 inch (181.48 mm)
ProductCode Description O-Rings - Backup Rings