FLOW RATE CONTROL VALVE

PURPOSE:To prevent a valve box from being damaged by an erosion even if a jet from a small hole generates a cavitation, by curtailing the number of valve boxes of a flow rate control valve, attaching directly a cage and an inner valve to a tank, and jetting a jet from the cage into stored water in the tank. CONSTITUTION:High pressure water which has flowed in from a valve inlet 30 passes through a valve seat 23 and goes into an inside 31 of a cage 22, passes through many small holes 22a provided on the cage 22 and jets into stored water 1a of a flow rate control valve chamber 1b which has been attached to a tank 1. In case a flow rate control valve opening is an intermediate opening, a part of the small holes 22a of the cage 22 is closed by an inner valve 21, therefore, a flow rate flowing out to the tank 1 from the cage 22 decreases. However, since there is no multistage orifice, a differential pressure of the small hole of the cage is roughly constant. In this way, since an inner valve with a balance hole is used, there is an effect for reducing a driving force for a control of a large flow rate, and since a flow rate control valve 20 is provided, the installation plate and its direction can be selected freely.