This back-up ring is supplied in AS568-355 white PTFE (Teflon) 55 Shore D with an inside diameter of 5.225 in (132.72 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.645 in (143.38 mm), catalogued under part number TST355. It extends o-ring service life by supporting the seal against extrusion under high pressure.
The compound resists nearly all industrial chemicals, oxidizing media, and solvents. PTFE (Teflon) is specified for near-universal chemical inertness and excellent dielectric properties. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Applications involving elemental fluorine at temperature or service requiring elastic recovery call for a different compound.
You will find this material specified across aggressive-media pipelines, pharmaceutical and biotech, and semiconductor fabrication.
Order part number TST355, sold individually. Nominal inside diameter is listed as 5 1/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description 2103-355 PTFE S/T BUP FDA
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 5.225 inch (132.72 mm)
Actual Outside Diameter 5.645 inch (143.38 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings