8-175 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90175, an AS568-175 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 8.987 in (228.27 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 9.193 in (233.5 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.

Viton® (FKM) is specified here for industry benchmark where nitrile reaches its thermal limit and outstanding high-temperature capability. The material holds up against aggressive chemicals, engine and transmission fluids, and chlorinated solvents. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where low-molecular-weight organic acids or ketones and esters are present.

Typical settings include aerospace, automotive fuel systems, and oil and gas.

Stocked as VBU90175 and sold individually. 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.