housing floor 72 that is fixed in location wherein the radial setback functions as a third stop a 2 see fig1 and 1 c at the drive side end of the second adjusting rod 4 a a recess section 4 b is formed that relative to the position shown and in the closed position of the double seat valve 1 ends with the lower edge thereof below the third stop a 2 by a defined axial distance in accordance with this axial distance upon pressurization of the third pressure medium chamber 86 with a third pressure medium d 3 the recess section 4 b and thus the second closing element 4 securely connected to this via the second adjusting rod 4 a are pushed upward by a second partial stroke t 2 with this second partial stroke t 2 the second closing element 4 is transferred into a second partially open position t 2 a second seat cleaning position in which a second annular gap s 2 acting as a throttle gap is formed between a leakage cavity side cylindrical attachment not identified on the second closing element 4 and the connection opening 2 c via which a second seat cleaning flow r 2 can arrive from the second valve housing part 2 b via the exposed second seat 2 e into the leakage cavity 5 and from.