| 摘要 |
<p>A quick action valve for use with fluid or vacuum lines has a permanent magnet assembly for urging the valve member onto the valve seat. The valve is normally opened and is so designed that after closing it may not reopen of its own accord whatever the later changes in direction of flow or whatever the variations in pressure. The closing force is exerted by magnets. Once it has shut, the valve may only be reopened by external mechanical or magnetic action.</p> |
