| 摘要 |
<p>The invention relates to a valve for a pipe or reservoir, comprising a housing, a shut-off element, a rotatable operating shaft which runs through the housing, and a primary seal on the shaft. Seen from the shut-off element a secondary seal is placed beyond the primary seal about the shaft. The secondary seal comprises a flexible bellows seal and a magnetic fluid seal ahead of and beyond which a fireproof shut-off ring is arranged about the shaft. Leakage from the pipe is detected with the help of a monitoring system. By means of a monitoring system it is checked whether or not leakage to the surroundings is taking place, whether maintenance should be carried out and whether the seal and/or portions thereof are intact.</p> |
