TST450 is an AS568-450 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 10.475 in (266.07 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 11.025 in (280.04 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
The compound resists strong acids and bases, steam, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) is specified for one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. 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, food and beverage, and semiconductor fabrication.
Stocked as TST450 and sold individually. Nominal inside diameter is listed as 10 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Description **2103-450 PTFE S/T BUP FDA
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 10.475 inch (266.07 mm)
Actual Outside Diameter 11.025 inch (280.04 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings