To overcome the shortcomings of the shear pin typejoint and left-hand thread typejoint, a sliding sleeve subsurface safety joint is developed.
为了克服剪钉式和反扣式两种安全接头的不足，研制出一种滑套式井下安全接头。
2
In the light of the disadvantages and limitation of the existing unscrewing type or shearing type safety joints, a hydraulic sleevetype safety joint is designed.
针对现有倒扣式和剪断式安全接头结构上的局限性和缺陷，设计了液压滑套式安全接头。
3
The method of 5-ring screw hoop, 1-pen hoop and non-shrinkage high-strength mortar poured into sleeve is used at the seismic joint of new-type prefabricated reinforced concrete beam-column.