Ordered as TST346, this is an AS568-346 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 4.1 in (104.14 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.52 in (114.81 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
As a material, PTFE (Teflon) is widely chosen for a very wide continuous service temperature range and near-universal chemical inertness. It resists strong acids and bases, nearly all industrial chemicals, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Exposure to molten alkali metals or service requiring elastic recovery will shorten service life.
You will find this material specified across food and beverage, semiconductor fabrication, and chemical processing.
This item is sold individually under part number TST346. Nominal inside diameter is listed as 4 1/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
description 2103-346 PTFE S/T BUP FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 4.1 inch (104.14 mm)
Actual_OD 4.52 inch (114.81 mm)
ProductCode Description O-Rings - Backup Rings