The cage control valve adopts a cage pressure balanced structure, and a pressure balance hole is set on the plug to effectively eliminate the axial unbalanced force acting on the upper and lower parts of the plug.

        The cage control valve adopts the valve body of a single-seat control valve, and a cylindrical cage is inserted into the valve body. Guided by the cage, a plug that moves up and down in the axial direction is installed. The hole with flow characteristics changes the opening area through the plug and the cage hole to achieve the purpose of adjusting the flow.

        The cage is fastened to the valve body by three gaskets, and no bolts are required to install the cage. According to the requirements of different flow characteristics, it can be easily replaced with a linear flow characteristic cage or an equal percentage flow characteristic cage. Cages with different flow capacities can be replaced according to different requirements of flow rate.

        There is two stepped valve seat sealing surfaces in the cage of the DOCN cage control valve. The sealing is completed by cooperating with the two sealing surfaces on the plug. Compared with one sealing surface of the single-seat control valve, the leakage level is increased. If it is larger, its leakage level is equivalent to that of a double-seat control valve. However, the unbalanced force of the valve core is much smaller than that of the single-seat control valve and the double-seat control valve. Its stability is better than that of the double-seat control valve. When the opening of the double-seat control valve exceeds 60-70%, an unstable area will appear, causing the valve core to vibrate. The cage control valve has no unstable area, and the phenomenon of unbalanced force reversal will not occur. At the same time, the guide part of the plug and the cage are big, which will not cause vibration.