Part number TST123 is an AS568-123 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.174 in (29.82 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.38 in (35.05 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
The compound resists nearly all industrial chemicals, steam, and solvents. PTFE (Teflon) is valued for excellent dielectric properties and one of the lowest coefficients of friction of any solid. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. Applications involving elemental fluorine at temperature or molten alkali metals call for a different compound.
Maintenance and OEM teams specify it across aggressive-media pipelines, laboratory equipment, and food and beverage.
Reference part number TST123 when ordering; the item is sold individually. Nominal inside diameter is listed as 1 3/16 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 2103-123 PTFE S/T BUP FDA
uf_description2 30.66 X 35.03 X 1.23MM
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 1.174 inch (29.82 mm)
Actual_OD 1.38 inch (35.05 mm)
ProductCode Description O-Rings - Backup Rings