Parri three way control valve has three inlets and outlets connected to pipeline, which is equivalent to integration of two single seated valves. According to mode of action, it is divided into three way flow mixing control valve and three way flow splitting control valve. A flow mixing control valve is one in which two fluids are mixed through the valve, for example, a fluid of two different temperatures is mixed through a valve to a fluid having a temperature between the first two. This kind of valve has two inlets and one outlet. Flow splitting control valve divides a fluid into two paths after passing through the valve. When the valve closes an outlet, it opens another outlet. The valve has one inlet and two outlets.