Part number TST393 is an AS568-393 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 23.94 in (608.08 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 24.36 in (618.74 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
PTFE (Teflon) is specified for non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. The compound resists solvents, oxidizing media, and strong acids and bases. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in service requiring elastic recovery or molten alkali metals.
It sees regular use in chemical processing, laboratory equipment, and semiconductor fabrication.
Reference part number TST393 when ordering; the item is sold individually. Nominal inside diameter is listed as 24 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
description 2103-393 PTFE S/T BUP FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 23.94 inch (608.08 mm)
Actual_OD 24.36 inch (618.74 mm)
ProductCode Description O-Rings - Backup Rings