APG stocks the TSP261, an AS568-261 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 6.734 in (171.04 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 7.012 in (178.1 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is widely chosen for one of the lowest coefficients of friction of any solid and a very wide continuous service temperature range. This material stands up to nearly all industrial chemicals, solvents, and oxidizing media. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in molten alkali metals or service requiring elastic recovery.
Common environments for this compound include pharmaceutical and biotech, laboratory equipment, and semiconductor fabrication.
Order part number TSP261, sold individually. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Description *2107-261 PTFE SPIRAL B/U FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 6.734 inch (171.04 mm)
Actual Outside Diameter 7.012 inch (178.1 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings