A flow control manifold assembly, constructed of a number of manifold valve assemblies. Each manifold valve assembly is formed of first and second valve bodies, each body having at least one inlet port and a plurality of outlet ports. The two valve bodies are connected together in fluid communication with each other. Associated with each valve body is an actuator assembly, which includes a valve actuator and an actuator rod attached to and projecting outward from the actuator, and actuatable by the actuator. In at least one of the valve bodies, a bonnet is affixed to the actuator, and projects into the respective one of the valve bodies. A valve stem, carrying at least one valve plug, is attached to the projecting end of the actuator rod, positioning the valve plug on the opposite side of the bonnet from the actuator. The bonnet includes a valve seat for engagement with the valve plug when the valve plug is actuated to a predetermined position by the actuator. One embodiment provides a third valve body, also in fluid communication with the first valve body, so that flow from one source to two destinations can be controlled by a single valve assembly. Thus the invention replaces a single, expensive, multiple-actuator valve with a pair of inexpensive single-actuator valves which together are less expensive than the single valve they replace, while still preventing the mixing of different types of fluids.