Ordered as TST329, this is an AS568-329 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.975 in (50.17 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.395 in (60.83 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
This material stands up to nearly all industrial chemicals, oxidizing media, and strong acids and bases. PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Verify compatibility before use with service requiring elastic recovery or molten alkali metals.
It sees regular use in semiconductor fabrication, aggressive-media pipelines, and pharmaceutical and biotech.
Reference part number TST329 when ordering; the item is sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application.
description 2103-329 PTFE S/T BUP FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 1.975 inch (50.17 mm)
Actual_OD 2.395 inch (60.83 mm)
ProductCode Description O-Rings - Backup Rings