APG stocks the TST033SO, an AS568-033 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 1.989 in (50.52 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 2.129 in (54.08 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
PTFE (Teflon) is specified here for one of the lowest coefficients of friction of any solid and very wide continuous service temperature range. The material holds up against oxidizing media, solvents, and strong acids and bases. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Applications involving service requiring elastic recovery or elemental fluorine at temperature call for a different compound.
Typical settings include food and beverage, pharmaceutical and biotech, and chemical processing.
TST033SO ships individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description 033 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.07 inch (1.78 mm)
Actual Inside Diameter 1.989 inch (50.52 mm)
Actual Outside Diameter 2.129 inch (54.08 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings