*2107-348 PTFE SPIRAL B/U FDA

APG stocks the TSP348, an AS568-348 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 4.35 in (110.49 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.77 in (121.16 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

PTFE (Teflon) is specified here for excellent dielectric properties and near-universal chemical inertness. It resists strong acids and bases, solvents, and nearly all industrial chemicals. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C).

It sees regular use in pharmaceutical and biotech, semiconductor fabrication, and laboratory equipment.

Reference part number TSP348 when ordering; the item is sold individually. Nominal inside diameter is listed as 4 3/8 inch. Review your operating media and conditions against this specification before installation.