Q-390 FLUOROELASTOMER 75 Q RING

Part number QV70390 is an AS568-390 black Viton® (FKM) 75 Shore A Quad-Ring measuring an inside diameter of 20.953 in (532.21 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 21.373 in (542.87 mm). A quad-ring provides a dual sealing band on each contact face for improved reliability.

As a material, Viton® (FKM) is widely chosen for very low compression set at elevated temperature and the industry benchmark where nitrile reaches its thermal limit. Expect good resistance to chlorinated solvents, petroleum oils and fuels, and aggressive chemicals. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Applications involving low-molecular-weight organic acids or amines call for a different compound. The profile itself contributes resistance to the spiral twisting that defeats round-section rings and lower compressive load required to achieve a seal.

Maintenance and OEM teams specify it across oil and gas, automotive fuel systems, and semiconductor equipment.

Order part number QV70390, sold individually. Nominal inside diameter is listed as 21 inch. Review your operating media and conditions against this specification before installation.