According to actual needs. there are circulating sub with casing thread and circulating sub with union thread.

根据需要可分为套管螺纹循环接头和油壬螺纹循环接头(全规格)。

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The landing is thread connected with stop ring and tightened on and put into downhole with drill string. The landing sub is used as a sub above drill string before check valve is run in downhole.

就位接头与止动环用螺纹联结并上紧扣和钻柱连接下入井内，在未投入止回阀时作为钻柱上的一个接头。

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Taking the conical thread as the object of study, a sub-pixel image detection method for the mechanical part linear edge based on the support vector regression was proposed.

以锥形螺纹为研究对象，提出了一个基于支持向量回归的机械零件直线边缘亚像素图像检测方法。

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Their cases share a common thread -- repeated concussions, sub-concussive blows to the head, or both.

CNN: NFL wants players' suit over concussions dismissed