8-330 BLACK FKM 90D BACK-UP RING

Ordered as VBU90330, this is an AS568-330 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 2.1 in (53.34 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.52 in (64.01 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

As a material, Viton® (FKM) offers long service life in hot, chemically aggressive environments and the industry benchmark where nitrile reaches its thermal limit. It resists chlorinated solvents, many acids, and aromatic hydrocarbons. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Exposure to ketones and esters or low-molecular-weight organic acids will shorten service life.

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

Reference part number VBU90330 when ordering; the item is sold individually. Unit weight is approximately 2.662 g and nominal inside diameter is listed as 2 1/8 inch. 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.