The TST176 is an AS568-176 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 9.237 in (234.62 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 9.443 in (239.85 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
As a material, PTFE (Teflon) is known for a very wide continuous service temperature range and excellent dielectric properties. It resists oxidizing media, strong acids and bases, and nearly all industrial chemicals. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C).
You will find this material specified across aggressive-media pipelines, chemical processing, and semiconductor fabrication.
Stocked as TST176 and sold individually. Nominal inside diameter is listed as 9 1/4 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 2103-176 PTFE S/T BUP FDA
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 9.237 inch (234.62 mm)
Actual_OD 9.443 inch (239.85 mm)
ProductCode Description O-Rings - Backup Rings