8-444 BLACK FKM 90D BACK-UP RING

Part number VBU90444 is an AS568-444 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 7.725 in (196.22 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 8.275 in (210.19 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.

The material holds up against engine and transmission fluids, chlorinated solvents, and aggressive chemicals. Viton® (FKM) is known for the industry benchmark where nitrile reaches its thermal limit, excellent resistance to compression set and permeation. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). It is not the right choice where amines or hot water and steam are present.

Maintenance and OEM teams specify it across aerospace, oil and gas, and high-temperature process equipment.

VBU90444 ships individually. Unit weight is approximately 18.262 g. Review your operating media and conditions against this specification before installation.