APG stocks the TST431SO, an AS568-431 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 5.225 in (132.72 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.775 in (146.69 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
The compound resists nearly all industrial chemicals, solvents, and steam. PTFE (Teflon) is specified for excellent dielectric properties and a very wide continuous service temperature range. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It is not the right choice where molten alkali metals or elemental fluorine at temperature are present.
It sees regular use in aggressive-media pipelines, pharmaceutical and biotech, and laboratory equipment.
This item is sold individually under part number TST431SO. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. 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 431 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 5.225 inch (132.72 mm)
Actual Outside Diameter 5.775 inch (146.69 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings