| 摘要 |
<p>The invention is directed to a double seat valve with means for preventing leakage. A shared drive unit is provided for the actuation of the two valve disks (6, 7). This drive unit contains a cylinder (17) with a first work piston (18) which is loaded at both sides by pressure springs (29, 22) and is fixedly connected with the valve stem or valve shaft (13) of the lower valve disk (7), this valve disk (13) penetrating the upper valve disk (6) and its tubular shaft (14) in a telescoping manner, the shaft, in turn, projecting into the cylinder (17) by its upper end and having an abutment (28) at that location for the lower pressure spring (29) which presses the upper valve disk (6) into its seat (8), and a second work piston (36) which acts on the tubular shaft and is movable on the tubular shaft is arranged under the first work piston (18) in the cylinder (17), and a third work piston (30) which acts on the lower valve disk is arranged above the first work piston. The first spring (22) is arranged so as to be supported at the third piston (30) so that the drive consumes less air and the valve switches faster.</p> |
