TSP328 is an AS568-328 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 1.85 in (46.99 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.27 in (57.66 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
PTFE (Teflon) is specified here for non-stick, non-contaminating surface characteristics and excellent dielectric properties. The material holds up against oxidizing media, nearly all industrial chemicals, and steam. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where elemental fluorine at temperature or service requiring elastic recovery are present.
You will find this material specified across aggressive-media pipelines, chemical processing, and food and beverage.
This item is sold individually under part number TSP328. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 2107-328 PTFE SPIRAL B/U FDA
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 1.85 inch (46.99 mm)
Actual_OD 2.27 inch (57.66 mm)
ProductCode Description O-Rings - Backup Rings