Ordered as TSP239, this is an AS568-239 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 3.609 in (91.67 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.887 in (98.73 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
As a material, PTFE (Teflon) is valued for a very wide continuous service temperature range and excellent dielectric properties. The material holds up against strong acids and bases, nearly all industrial chemicals, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service. It is not the right choice where elemental fluorine at temperature or molten alkali metals are present.
Common environments for this compound include food and beverage, pharmaceutical and biotech, and aggressive-media pipelines.
TSP239 ships individually. Nominal inside diameter is listed as 3 5/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.
Description *2107-239 PTFE SPIRAL B/U FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 3.609 inch (91.67 mm)
Actual Outside Diameter 3.887 inch (98.73 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings