8-427 BLACK FKM 90D BACK-UP RING

Part number VBU90427 is an AS568-427 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 4.725 in (120.02 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.275 in (133.99 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

This material stands up to many acids, petroleum oils and fuels, and aromatic hydrocarbons. That behavior comes from the compound itself: Viton® (FKM) is valued for outstanding high-temperature capability and very low compression set at elevated temperature. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).

Typical settings include semiconductor equipment, aerospace, and high-temperature process equipment.

Stocked as VBU90427 and sold individually. Unit weight is approximately 11.45 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.