This back-up ring is supplied in AS568-347 white PTFE (Teflon) 55 Shore D built to 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), catalogued under part number TST347SO. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
PTFE (Teflon) is known for one of the lowest coefficients of friction of any solid and excellent dielectric properties. It resists nearly all industrial chemicals, strong acids and bases, and oxidizing media. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Exposure to elemental fluorine at temperature or service requiring elastic recovery will shorten service life.
Common environments for this compound include food and beverage, aggressive-media pipelines, and laboratory equipment.
TST347SO ships individually. Nominal inside diameter is listed as 4 1/4 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 347 PTFE SOLID BACKUP RING 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