This back-up ring is supplied in AS568-207 white PTFE (Teflon) 55 Shore D measuring an inside diameter of 0.546 in (13.87 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.824 in (20.93 mm), catalogued under part number TST207. It extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is specified here for near-universal chemical inertness and excellent dielectric properties. The compound resists solvents, steam, and nearly all industrial chemicals. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Verify compatibility before use with service requiring elastic recovery or molten alkali metals.
You will find this material specified across chemical processing, semiconductor fabrication, and food and beverage.
Reference part number TST207 when ordering; the item is sold individually. Nominal inside diameter is listed as 9/16 inch. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 2103-207 PTFE S/T BUP FDA
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 0.546 inch (13.87 mm)
Actual_OD 0.824 inch (20.93 )
ProductCode Description O-Rings - Backup Rings