8-340 BLACK FKM 90D BACK-UP RING

VBU90340 is an AS568-340 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 3.35 in (85.09 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 3.77 in (95.76 mm). In service, this back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Viton® (FKM) delivers excellent resistance to compression set and permeation, the industry benchmark where nitrile reaches its thermal limit. This material stands up to engine and transmission fluids, chlorinated solvents, and aggressive chemicals. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). It should not be specified for service in low-molecular-weight organic acids or hot water and steam.

You will find this material specified across automotive fuel systems, aerospace, and chemical processing.

Order part number VBU90340, sold individually. Unit weight is approximately 3.9621 g and nominal inside diameter is listed as 3 3/8 inch. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.