The TST347 is an AS568-347 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 4.225 in (107.32 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.645 in (117.98 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is specified here for excellent dielectric properties and non-stick, non-contaminating surface characteristics. Expect good resistance to oxidizing media, strong acids and bases, and solvents. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Applications involving service requiring elastic recovery or elemental fluorine at temperature call for a different compound.
Common environments for this compound include pharmaceutical and biotech, food and beverage, and semiconductor fabrication.
Order part number TST347, sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.
description 2103-347 PTFE S/T BUP FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 4.225 inch (107.32 mm)
Actual_OD 4.645 inch (117.98 mm)
ProductCode Description O-Rings - Backup Rings