**383 PTFE SOLID BACKUP RING FDA

APG stocks the TST383SO, an AS568-383 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 13.975 in (354.97 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 14.395 in (365.63 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) offers non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. Expect good resistance to strong acids and bases, 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 molten alkali metals.

Typical settings include chemical processing, aggressive-media pipelines, and semiconductor fabrication.

Order part number TST383SO, sold individually. Nominal inside diameter is listed as 14 inch. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.