| 摘要 |
An automatic vacuum isolation valve network for use in a vacuum collection system having at least two branches connected to a main vacuum pipe maintained under negative pressure. The network includes a first valve located in each branch adapted to close in response to vacuum loss in the main vacuum pipe, thereby preserving a vacuum level in the associated branch. The network further includes a shut-off valve located in each branch upstream of the first valve, the shut-off valve adapted to close in response to vacuum loss in an upstream portion of a branch. The shut-off valve thereby isolates a broken branch, and allows a remainder of the vacuum collection system to return to normal operation. The isolation valve network further facilitates location of a breach in the vacuum collection system by rendering a faulty branch inoperable, thereby identifying the immediate vicinity of the breach.
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