Part number TSP245 is an AS568-245 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 4.359 in (110.72 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.637 in (117.78 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
PTFE (Teflon) is specified here for near-universal chemical inertness and one of the lowest coefficients of friction of any solid. This material stands up to solvents, steam, and strong acids and bases. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Applications involving molten alkali metals or elemental fluorine at temperature call for a different compound.
Common environments for this compound include aggressive-media pipelines, laboratory equipment, and pharmaceutical and biotech.
Order part number TSP245, sold individually. Nominal inside diameter is listed as 4 3/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Description 2107-245 PTFE SPIRAL B/U FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 4.359 inch (110.72 mm)
Actual Outside Diameter 4.637 inch (117.78 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings