求翻译：必要时工件要在清水槽中上下串动2~3次，是什么意思？

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If necessary, the workpiece to string up and down in clear water tank interactive 2~ 3th,

The operator should inspect strictly whether has the air vent and flows the zinc hole (air vent and flows zinc hole to be supposed for opposite angle), the material quality different, the corrosion degree difference very big treats plates to be supposed to classify carries on the acid pickling, if t

Necessary artifacts to string up and down in a clearing sink 2~3,