Part number TST131 is an AS568-131 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.674 in (42.52 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.88 in (47.75 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 a very wide continuous service temperature range and excellent dielectric properties. The material holds up against oxidizing media, solvents, and steam. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Exposure to molten alkali metals or elemental fluorine at temperature will shorten service life.
Maintenance and OEM teams specify it across laboratory equipment, pharmaceutical and biotech, and food and beverage.
Order part number TST131, sold individually. Nominal inside diameter is listed as 1 11/16 inch. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description 2103-131 PTFE S/T BUP FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 1.674 inch (42.52 mm)
Actual Outside Diameter 1.88 inch (47.75 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings