The TST226SO is an AS568-226 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 1.984 in (50.39 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 2.262 in (57.45 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
The material holds up against oxidizing media, strong acids and bases, and steam. That behavior comes from the compound itself: PTFE (Teflon) is known for one of the lowest coefficients of friction of any solid and excellent dielectric properties. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where service requiring elastic recovery or elemental fluorine at temperature are present.
Maintenance and OEM teams specify it across pharmaceutical and biotech, chemical processing, and food and beverage.
Order part number TST226SO, sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description *226 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 1.984 inch (50.39 mm)
Actual Outside Diameter 2.262 inch (57.45 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings