This back-up ring is supplied in AS568-118 white PTFE (Teflon) 55 Shore D with an inside diameter of 0.862 in (21.89 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.068 in (27.13 mm), catalogued under part number TST118. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
As a material, PTFE (Teflon) is valued for a very wide continuous service temperature range and one of the lowest coefficients of friction of any solid. The compound resists oxidizing media, solvents, and nearly all industrial chemicals. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It is not the right choice where service requiring elastic recovery or molten alkali metals are present.
Typical settings include chemical processing, pharmaceutical and biotech, and aggressive-media pipelines.
Order part number TST118, sold individually. Review your operating media and conditions against this specification before installation.
Description 2103-118 PTFE S/T BUP FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 0.862 inch (21.89 mm)
Actual Outside Diameter 1.068 inch (27.13 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings