| 摘要 |
The valve upper part has a head piece, in which a spindle (2) is rotatably mounted and which receives a set-back piston. A sleeve (3) is arranged between the spindle and the set-back piston, in which the set-back piston is received. The sleeve is connected with a pressure piece (4) which is mounted in an axially displaceable manner in the head piece. |
