Ordered as TST322SO, this is an AS568-322 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.225 in (31.12 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.645 in (41.78 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
It resists steam, nearly all industrial chemicals, and strong acids and bases. That behavior comes from the compound itself: PTFE (Teflon) is specified for excellent dielectric properties and non-stick, non-contaminating surface characteristics. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Verify compatibility before use with service requiring elastic recovery or molten alkali metals.
It sees regular use in laboratory equipment, pharmaceutical and biotech, and aggressive-media pipelines.
Reference part number TST322SO when ordering; the item is sold individually. Nominal inside diameter is listed as 1 1/4 inch. Review your operating media and conditions against this specification before installation.
Description *322 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.21 inch (5.33 mm)
Actual Inside Diameter 1.225 inch (31.12 mm)
Actual Outside Diameter 1.645 inch (41.78 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings