The TST145SO is an AS568-145 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 2.55 in (64.77 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.756 in (70 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
As a material, PTFE (Teflon) delivers a very wide continuous service temperature range and near-universal chemical inertness. It resists steam, strong acids and bases, and solvents. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in elemental fluorine at temperature or molten alkali metals.
Maintenance and OEM teams specify it across aggressive-media pipelines, food and beverage, and laboratory equipment.
Reference part number TST145SO when ordering; the item is sold individually. Nominal inside diameter is listed as 2 9/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Description 145 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 2.55 inch (64.77 mm)
Actual Outside Diameter 2.756 inch (70 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings