Part number TSP020 is an AS568-020 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 0.864 in (21.95 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 1.004 in (25.5 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
As a material, PTFE (Teflon) is valued for excellent dielectric properties and non-stick, non-contaminating surface characteristics. It resists strong acids and bases, solvents, and steam. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service.
You will find this material specified across aggressive-media pipelines, pharmaceutical and biotech, and laboratory equipment.
Order part number TSP020, sold individually. Nominal inside diameter is listed as 7/8 inch. Check the compound against your process media, pressure and temperature before committing to a design. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.
description 2107-020 PTFE SPIRAL B/U FDA
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 0.864 inch (21.95 mm)
Actual_OD 1.004 inch (25.5 mm)
ProductCode Description O-Rings - Backup Rings