摘要 |
<p>A high-pressure control valve (2) used in chromatography serves as a counter pressure control valve which, in a separating column, is intended to maintain a specific predeterminable pressure. The valve has a valve seat (12) with an outlet channel opening (18) located in its center and a valve body (13) that cooperates with the valve seat. The valve body (13) can be moved with the aid of a piezo transducer, actively in the opening direction and, while being monitored, actively in the closing direction. The opposed faces of the valve seat (12) and the valve body (13) are so shaped that an annular gap (16) that widens radially towards the outside starting from the opening (18) of the outlet channel is produced. When the valve is in the closed position, this results in the formation of a narrow sealing zone directly at the edge of the opening of the outlet channel.</p> |