APG stocks the TST325SO, an AS568-325 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 1.475 in (37.47 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.895 in (48.13 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
As a material, PTFE (Teflon) is widely chosen for near-universal chemical inertness and excellent dielectric properties. The material holds up against strong acids and bases, solvents, and steam. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C).
You will find this material specified across semiconductor fabrication, pharmaceutical and biotech, and chemical processing.
TST325SO ships individually. Application requirements vary, so validate compatibility with your process conditions prior to installation.
Description 325 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 1.475 inch (37.47 mm)
Actual Outside Diameter 1.895 inch (48.13 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings