-421 BROWN FKM 75D O-RING

VB75421 is an AS568-421 brown Viton® (FKM) 75 Shore A O-Ring measuring an inside diameter of 3.975 in (100.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 4.525 in (114.94 mm). In service, this o-ring delivers dependable bidirectional sealing in a compact groove envelope.

Expect good resistance to petroleum oils and fuels, aromatic hydrocarbons, and aggressive chemicals. That behavior comes from the compound itself: Viton® (FKM) is specified for excellent resistance to compression set and permeation, very low compression set at elevated temperature. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Applications involving low-molecular-weight organic acids or hot water and steam call for a different compound.

You will find this material specified across chemical processing, aerospace, and high-temperature process equipment.

VB75421 ships individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.