159 PTFE SOLID BACKUP RING FDA

The TST159SO is an AS568-159 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 4.987 in (126.67 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 5.193 in (131.9 mm). This back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

The material holds up against solvents, steam, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) is known for non-stick, non-contaminating surface characteristics 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 elemental fluorine at temperature or service requiring elastic recovery are present.

Maintenance and OEM teams specify it across food and beverage, laboratory equipment, and aggressive-media pipelines.

Order part number TST159SO, sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application.