The pressure of the steam used in the vacuum pump of VD refining furnace is stable, but its flow is periodic.

VD精炼炉的真空抽气泵工作时蒸汽压力稳定而流量具有周期性，间断使用。

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The pressure of the steam used in the vacuum pump of VD refining furnace is stable, but its flow is periodic.

VD精炼炉的真空抽气泵工作时蒸汽压力稳定而流量具有周期性，间断使用。

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