TSP248 is an AS568-248 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 4.734 in (120.24 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.012 in (127.3 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
Expect good resistance to steam, solvents, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) is widely chosen for a very wide continuous service temperature range and one of the lowest coefficients of friction of any solid. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Exposure to elemental fluorine at temperature or molten alkali metals will shorten service life.
Maintenance and OEM teams specify it across semiconductor fabrication, pharmaceutical and biotech, and laboratory equipment.
Order part number TSP248, sold individually. Nominal inside diameter is listed as 4 3/4 inch. Check the compound against your process media, pressure and temperature before committing to a design.
Description *2107-248 PTFE SPIRAL B/U FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 4.734 inch (120.24 mm)
Actual Outside Diameter 5.012 inch (127.3 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings