Air pumps are involved, but their role is limited to creating a partial vacuum in the pipes in order to reduce resistance to the capsules' movement.

也使用气泵，但作用仅限于在管道中制造半真空，以减小胶囊运行的阻力。

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This type of vacuum pumps and high structure is simple, easy to use, reliable, maintenance-friendly features.

该型泵具有真空度高、结构简单，使用方便、工作可靠、维护方便的特点。

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The vacuum system utilizes two vacuum pumps and one booster pump to achieve a vacuum.

真空系统采用两台真空泵和一台罗茨泵来实现真空。

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