| 摘要 |
<p>A flow loading unloader valve (36) wherein the operating force for moving the valve (36) from the unloaded condition to the loaded condition is supplied by the flow through the valve (36) itself. The valve (36), which may be interposed between a fluid supply (24) and a high pressure load (26), comprises a valve body (38), having an inlet (40), a working outlet (42), a bypass outlet (44), and a valve operator (48), which may include a spool (49), that controls the direction of flow through the body (38). Movement of the valve operator (48) to change the valve (36) from the unloaded condition to the loaded condition is accomplished by applying the differential pressure created by the flow of fluid from the inlet (40) to the bypass outlet (44) to the piston ends. As the pressure increases as a result of increased flow resistance through the valve (36), the valve operator (48) moves from an unloaded to a loaded position, terminating flow to the bypass port (44) and resulting in high pressure flow to the working outlet (42). <IMAGE></p> |
