APG stocks the TSP137, an AS568-137 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 2.05 in (52.07 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.256 in (57.3 mm). A 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 one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. The material holds up against solvents, steam, and nearly all industrial chemicals. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It should not be specified for service in elemental fluorine at temperature or service requiring elastic recovery.
Common environments for this compound include laboratory equipment, chemical processing, and food and beverage.
Reference part number TSP137 when ordering; the item is sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
description *2107-137 PTFE SPIRAL B/U FDA
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 2.05 inch (52.07 mm)
Actual_OD 2.256 inch (57.3 mm)
ProductCode Description O-Rings - Backup Rings