The TST170SO is an AS568-170 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 7.737 in (196.52 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 7.943 in (201.75 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
The material holds up against steam, oxidizing media, and strong acids and bases. PTFE (Teflon) is widely chosen for one of the lowest coefficients of friction of any solid and excellent dielectric properties. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service.
Maintenance and OEM teams specify it across laboratory equipment, pharmaceutical and biotech, and semiconductor fabrication.
Reference part number TST170SO when ordering; the item is sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 170 PTFE SOLID BACKUP RING FDA
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 7.737 inch (196.52 mm)
Actual_OD 7.943 inch (201.75 mm)
ProductCode Description O-Rings - Backup Rings