The TST125SO is an AS568-125 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 1.299 in (32.99 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.505 in (38.23 mm). This back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
PTFE (Teflon) is specified here for excellent dielectric properties and near-universal chemical inertness. The material holds up against oxidizing media, solvents, and nearly all industrial chemicals. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where molten alkali metals or elemental fluorine at temperature are present.
You will find this material specified across semiconductor fabrication, laboratory equipment, and food and beverage.
Reference part number TST125SO when ordering; the item is sold individually. Nominal inside diameter is listed as 1 5/16 inch. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 125 PTFE SOLID BACKUP RING FDA
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 1.299 inch (32.99 mm)
Actual_OD 1.505 inch (38.23 mm)
ProductCode Description O-Rings - Backup Rings