Ordered as TST173, this is an AS568-173 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 8.487 in (215.57 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 8.693 in (220.8 mm). The 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, nearly all industrial chemicals, and strong acids and bases. PTFE (Teflon) is specified for non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Verify compatibility before use with molten alkali metals or elemental fluorine at temperature.
You will find this material specified across food and beverage, laboratory equipment, and chemical processing.
Order part number TST173, sold individually. Review your operating media and conditions against this specification before installation.
Description 2103-173 PTFE S/T BUP FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 8.487 inch (215.57 mm)
Actual Outside Diameter 8.693 inch (220.8 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings