Ordered as TST127SO, this is an AS568-127 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 1.424 in (36.17 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.63 in (41.4 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.
As a material, PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and near-universal chemical inertness. It resists strong acids and bases, nearly all industrial chemicals, and solvents. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where service requiring elastic recovery or elemental fluorine at temperature are present.
Typical settings include chemical processing, aggressive-media pipelines, and pharmaceutical and biotech.
TST127SO ships individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.
Description 127 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 1.424 inch (36.17 mm)
Actual Outside Diameter 1.63 inch (41.4 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings