常見例句Keywords vacuum reaction stove;vacuum degree;master pump;forepump;smelting;modification; 真空感應(yīng)爐;真空度;主泵;前級(jí)泵;熔煉;改造;mechanical forepump 機(jī)械預(yù)抽真空泵forepumpn. 預(yù)抽真空泵(前級(jí)泵)vacuum forepump 前置真空泵 返回 forepumping