8-435 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-435 black Viton® (FKM) 90 Shore A supplied with an inside diameter of 5.725 in (145.42 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 6.275 in (159.39 mm), catalogued under part number VBU90435. It allows a standard o-ring to operate at higher pressures than it could unsupported.

This material stands up to many acids, engine and transmission fluids, and petroleum oils and fuels. That behavior comes from the compound itself: Viton® (FKM) is known for long service life in hot, chemically aggressive environments and the industry benchmark where nitrile reaches its thermal limit. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in low-molecular-weight organic acids or hot water and steam.

It sees regular use in automotive fuel systems, high-temperature process equipment, and aerospace.

Stocked as VBU90435 and sold individually. Unit weight is approximately 13.725 g and nominal inside diameter is listed as 5 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.