2103-434 PTFE S/T BUP FDA

Ordered as TST434, this is an AS568-434 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 5.6 in (142.24 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 6.15 in (156.21 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.

PTFE (Teflon) is specified here for excellent dielectric properties and one of the lowest coefficients of friction of any solid. It resists strong acids and bases, solvents, and nearly all industrial chemicals. The material carries a published service range of -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.

It sees regular use in pharmaceutical and biotech, semiconductor fabrication, and food and beverage.

Reference part number TST434 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 5/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.