Part number TST394SO is an AS568-394 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 24.94 in (633.48 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 25.36 in (644.14 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is specified here for excellent dielectric properties and near-universal chemical inertness. The material holds up against oxidizing media, nearly all industrial chemicals, and strong acids and bases. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Exposure to elemental fluorine at temperature or service requiring elastic recovery will shorten service life.
You will find this material specified across pharmaceutical and biotech, laboratory equipment, and aggressive-media pipelines.
Reference part number TST394SO when ordering; the item is sold individually. Nominal inside diameter is listed as 25 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.
description 394 PTFE SOLID BACKUP RING FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 24.94 inch (633.48 mm)
Actual_OD 25.36 inch (644.14 mm)
ProductCode Description O-Rings - Backup Rings