| 摘要 |
<p>A vacuum valve for use in a tanker is constructed with means for releasing a supplemental force on the valve body if the pressure drop across the vacuum valve rises substantially above a value designated for the vacuum valve. Such an extraordinary rise of the pressure drop will occur by escape from an injury under the water-line caused by grounding, and the supplemental closing froce will therefore close the valve very fast and will thereby contribute to maintaing a high vacuum in the tank, counteracting continued escape.</p> |
