Of equipment; without a motor and intended for hand operation (“a manual keypunch”; “a manual typewriter”).

对设备而言,指无马达和用手操作的设备(如人工键穿孔、人工)。

The briefing covers quality of the shell pierced by the three-high piercing mill, thespecific rolling failures and countermeasures thereagainst.

简地三辊穿孔所穿毛管的质量及该穿孔特有的轧制故障和预防措施。

Piercing mill is the most important equipment on the rolling pipe line,and the frame is the nucleal component of the piercing mill.

穿孔是轧制钢管的重设备,而架又是穿孔的核心组成部分。