| 摘要 |
A flow-control valve assembly for connection between a source of fluid under pressure and a fluid-operated load has a main valve and a pilot valve. The main valve defines a continuous flow path having an input end connectable to the source of fluid under pressure and an output end. This valve further has a valve member which defines with the housing of the main valve a plurality of variable flow restrictions, the valve member being displaceable in the main-valve housing between an open position wherein the restrictions are all of maximum flow cross section and a closed position wherein the restrictions are all of minimum flow cross section. A pilot valve has an input side connected to the output end of the continuous flow path through the main valve and an output side connectable to the load. The valve member of the main valve is displaced toward the open position when the pressure differential across the pilot valve decreases below a predetermined level and is displaced into the close position when this pressure differential increases above a predetermined level. A relatively soft spring biases the valve member into the open position.
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