| 摘要 |
The invention relates to an annular piston valve comprising the following features: - a housing that has an inlet and an outlet; - a rotationally symmetrical hollow member in the housing; - an annular duct between the housing and the hollow member; - a piston which is located in the hollow member and can move in and against the direction of flow; - two perforated cylinders which are concentric to the piston and are stacked inside one another; - one of the perforated cylinders has a greater axial length than the other perforated cylinder. |
