Kelly bar plug valve with floating valve seat

Abstract

The invention belongs to the field of drilling blowout prevention tool manufacturing and relates to blowout prevention tools, in particular to a kelly bar plug valve with a floating valve seat to solve the problems that a plug valve cannot be opened, the sealing surface is abraded, and a rotary bar is damaged due to the fact that the up-down differential pressure of the plug valve is large, and the specific pressure of the sealing surface is large. A floating mechanism composed of an upper valve seat, a wedge block, a top ring and a split semi-ring is adopted, an eccentric rotary knob is arranged, and the eccentric rotary knob and the floating mechanism form a cam mechanism. The position of the floating mechanism is adjusted by rotating the rotary knob, and the plug valve is opened through pressure of fluid.

Description

technical field [0001] The patent of the present invention relates to a blowout prevention tool for drilling, in particular to a kelly plug valve, which belongs to the field of blowout prevention tool manufacturing. Background technique [0002] Kelly cock valve is a manual blowout prevention tool in oil drill string circulation system. There are two types of upper kelly cock valve and lower kelly cock valve. It is an essential blowout prevention tool for drilling and workover. The operation of the Kelly plug valve is relatively simple, and the switch of the plug valve can be realized by rotating the rotary rod with a tool. [0003] In recent years, when the plug valve is closed, when the pressure difference between the top and bottom of the plug valve exceeds a certain value, the specific pressure between the plug valve ball and the wedge-shaped upper valve seat is too large, so that the opening of the plug valve needs to overcome a large frictional moment. Therefore, work...

AI Technical Summary

Problems solved by technology

Although the above problems have been solved to a certain extent, there are still some problems, such as the polymer materials used are prone to creep, sediments block the pressure relief channel and reduce the life of the plug valve, or the pressure difference between the two ends of the valve ball is large. , when the plug valve is opened, although the pressure of the liquid acting on the valve ball is converted to the wedge body, it is also converted to the rotary rod and the connecting rod. The axial force must not only overcome the frictional moment between the wedge body and the liquid Pressure component, but also to overcome the friction and friction torque between the rotary rod and the valve body, so the torque when opening is also relatively large

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