The TST426SO is an AS568-426 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 4.6 in (116.84 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.15 in (130.81 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
As a material, PTFE (Teflon) is valued 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). Applications involving service requiring elastic recovery or elemental fluorine at temperature call for a different compound.
You will find this material specified across laboratory equipment, chemical processing, and pharmaceutical and biotech.
Order part number TST426SO, sold individually. Nominal inside diameter is listed as 4 5/8 inch. Review your operating media and conditions against this specification before installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.
Description 426 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 4.6 inch (116.84 mm)
Actual Outside Diameter 5.15 inch (130.81 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings