174 PTFE SOLID BACKUP RING FDA

APG stocks the TST174SO, an AS568-174 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 8.737 in (221.92 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 8.943 in (227.15 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. Expect good resistance to oxidizing media, steam, and solvents. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C).

Maintenance and OEM teams specify it across semiconductor fabrication, chemical processing, and laboratory equipment.

Order part number TST174SO, sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.