Image Number 2 for United States Patent #6328535.
A flow control valve has body (20) containing a "bucket" shaped valve element (1) that moves in a bore (2). The valve element (1) has a discharge orifice (8) through which a needle valve (9) projects. Movement of the valve element (1) within the bore (2) adjusts the annular clearance between the orifice (8) and the needle (9) thereby varying the pressure drop across the valve element (1) and the rate of the main flow through the valve. The inlet (4a) to the body (20) is located upstream of the valve element. With this arrangement, the spill flow rate is adjusted by movement of the valve element (1) within the bore (2). However, in all cases the main flow of fluid passes through the orifice (8) of the valve element (1) through the bore (2) to the outlet (10), thereby avoiding the formation of stagnant "pools" of fluid within the bore (2) of the flow control valve.