Part number TST219 is an AS568-219 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 1.296 in (32.92 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.574 in (39.98 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
As a material, PTFE (Teflon) is specified for excellent dielectric properties and near-universal chemical inertness. Expect good resistance to solvents, strong acids and bases, and nearly all industrial chemicals. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Applications involving service requiring elastic recovery or elemental fluorine at temperature call for a different compound.
Typical settings include semiconductor fabrication, food and beverage, and chemical processing.
Order part number TST219, 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.
Description 2103-219 PTFE S/T BUP FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 1.296 inch (32.92 mm)
Actual Outside Diameter 1.574 inch (39.98 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings