Ordered as TST008, this is an AS568-008 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 0.176 in (4.47 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.316 in (8.03 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
PTFE (Teflon) is specified here for very wide continuous service temperature range and non-stick, non-contaminating surface characteristics. The material holds up against oxidizing media, strong acids and bases, and steam. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Exposure to molten alkali metals or service requiring elastic recovery will shorten service life.
Common environments for this compound include pharmaceutical and biotech, aggressive-media pipelines, and food and beverage.
Reference part number TST008 when ordering; the item is sold individually. Nominal inside diameter is listed as 3/16 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
description 2103-008 PTFE S/T BUP FDA
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 0.176 inch (4.47 mm)
Actual_OD 0.316 inch (8.03 mm)
ProductCode Description O-Rings - Backup Rings