摘要 |
Method and apparatus for achieving a high degree of vacuum pumping in an enclosure utilizing a single-stage pump. A vacuum pumping unit is coupled to a plurality of interconnected enclosures through a series of valves. When evacuation of a selected enclosure is desired, the valves are opened sequentially for a brief duration such that the enclosures are alternatively evacuated to the atmosphere and to other partially evacuated enclosures.
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