A mechanical device to position casing concentrically in the wellbore.

用于定位套管使其在井眼内居中的一种机械装置。

On the contrary, the design of Special Concentrically Braced Frames is saving and reasonable.

与此相反，特殊中心支撑框架的设计方法却是更经济、合理的。

The tubing die, Figure 10, extrudes plastic tubing concentrically around the emerging conductor.

螺纹模头(图10)，机械运行时塑料材料是围绕着导体延压出来。

The force to be measured must be applied concentrically along the central axis as far as possible.

所测量的力必须尽可能集中地沿着中心轴施加。

On the contrary, the design of Special Concentrically Braced Frames (SCBF) is saving and reasonable.

与此相反，特殊中心支撑框架的设计方法却是更经济、合理的。