Ordered as TST233, this is an AS568-233 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 2.859 in (72.62 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.137 in (79.68 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
The material holds up against nearly all industrial chemicals, steam, and strong acids and bases. That behavior comes from the compound itself: PTFE (Teflon) delivers non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Verify compatibility before use with molten alkali metals or elemental fluorine at temperature.
It sees regular use in semiconductor fabrication, aggressive-media pipelines, and food and beverage.
This item is sold individually under part number TST233. As always, verify media compatibility and operating conditions against the requirements of your specific application.
Description 2103-233 PTFE S/T BUP FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 2.859 inch (72.62 mm)
Actual Outside Diameter 3.137 inch (79.68 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings