Control valve assembly for controlling a process fluid flow in a process engineering plant such as a power plant, a chemical plant, a food processing plant or the like, wherein at least one fine-adjustment poppet valve with a fine-adjustment drive for the fine adjustment of a fine-adjustment poppet valve flow area; and at least one open/close poppet valve having a discrete adjustment actuator for placing the open/close poppet valve either into an open position, in which a poppet valve flow area is completely open, or into a closed position, in which the poppet valve flow area is closed off, wherein a cumulative total flow area of the adjustment valve assembly is defined by the fine-adjustment poppet valve flow area of the at least one fine-adjustment poppet valve and by the poppet valve flow area of the at least one open/close poppet valve.