Ordered as TSP247, this is an AS568-247 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 4.609 in (117.07 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.887 in (124.13 mm). The 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 known for excellent dielectric properties and one of the lowest coefficients of friction of any solid. It resists oxidizing media, steam, and nearly all industrial chemicals. Continuous operating temperature is published at -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 aggressive-media pipelines, chemical processing, and pharmaceutical and biotech.
Order part number TSP247, sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 2107-247 PTFE SPIRAL B/U FDA
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 4.609 inch (117.07 mm)
Actual_OD 4.887 inch (124.13 mm)
ProductCode Description O-Rings - Backup Rings