APG stocks the TST126, an AS568-126 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 1.362 in (34.59 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.568 in (39.83 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 near-universal chemical inertness and non-stick, non-contaminating surface characteristics. This material stands up to steam, solvents, and nearly all industrial chemicals. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C).
Typical settings include aggressive-media pipelines, chemical processing, and semiconductor fabrication.
This item is sold individually under part number TST126. Nominal inside diameter is listed as 1 3/8 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 2103-126 PTFE S/T BUP FDA
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 1.362 inch (34.59 mm)
Actual_OD 1.568 inch (39.83 mm)
ProductCode Description O-Rings - Backup Rings