ENGPAR Sales Pvt. Ltd. Supplies Duaflex Oil Control Piston Ring. ENGPAR Sales Pvt. Ltd. Offers piston rings. Duaflex Oil Control Piston Ring is made from high quality Grey C.I. Castings [Individual Casting] with an ideal combination of free and combined carbon to provide prolonged working life. Duaflex Oil Control Piston Ring is the casting used has a very fine grain to provide high tension even at elevated temperatures of high-speed engines. Each ring is properly inspected by modern techniques to ensure material and dimensional accuracy for the best results of high compression and less oil usage.