Under-pressure low-torque square drill rod plug valve

Abstract

The invention discloses an under-pressure low-torque square drill rod plug valve, and belongs to the technical field of drilling equipment. The plug valve comprises a valve body, a lower valve seat, a valve core and an upper valve seat, wherein the lower valve seat, the upper valve seat and the valve core are assembled in the valve body in a matched way, the upper part of the valve core is provided with a valve rod penetrating through the valve body in a matched way, a first sealing ring is arranged between assembling surfaces of the lower valve seat and the valve body, and the first sealing ring is a lip-shaped sealing ring. The under-pressure low-torque square drill rod plug valve has the advantages that the structure is simple, and the use is convenient. The problems that the opening difficulty of the traditional square drill rod plug valve is great at high pressure, the drilling operation is influenced and the like are solved. Through the improvement via the technical scheme, the opening and closing moment of the plug valve is greatly reduced, so that the opening of the plug valve at the high pressure becomes possible, in addition, the low-torque plug valve capable of being opened by a single person at the pressure difference being 70MPa can be realized, and the market and production site requirements are well met.

Description

technical field [0001] The invention relates to a valve, in particular to a kelly cock valve with low torque and belongs to the technical field of drilling equipment. Background technique [0002] The kelly plug valve is a ball valve structure, and the seal is formed by the steel ball and the cone surface of the valve seat. The function of the kelly cock valve is to prevent the formation pressure from pushing the mud to be ejected upward along the drill string water hole when the formation pressure exceeds the mud hydrostatic column pressure during the drilling process, so as to protect the hose from being suffocated due to high pressure. The use of the kelly cock valve can not only prevent the mud from spraying out from the water hole of the drilling tool, protect the hose from the damage of the formation high pressure, but also play a role in saving mud, keeping the rig clean and reducing environmental pollution. The most important The most important thing is to avoid ser...

AI Technical Summary

Problems solved by technology

[0003] The opening torque of the conventional kelly plug valve is too large due to the excessive friction torque between the steel ball inside the valve and the valve seat and between the operating knob and the body

In actual use, it is often necessary to open the plug valve. When the pressure difference between the two ends of the steel ball reaches 10 MPa or more, the single-person operation wrench and the afterburner lever cannot be opened, which seriously affects the normal use of the plug valve.

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