8-011 BLACK FKM 90D BACK-UP RING

Ordered as VBU90011, this is an AS568-011 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 0.301 in (7.65 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.441 in (11.2 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

The compound resists petroleum oils and fuels, chlorinated solvents, and engine and transmission fluids. That behavior comes from the compound itself: Viton® (FKM) is specified for excellent resistance to compression set and permeation, the industry benchmark where nitrile reaches its thermal limit. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service.

Maintenance and OEM teams specify it across high-temperature process equipment, semiconductor equipment, and automotive fuel systems.

This item is sold individually under part number VBU90011. Unit weight is approximately 0.0945 g and nominal inside diameter is listed as 5/16 inch. Review your operating media and conditions against this specification before installation.