Pressure balance type plug valve and driving device thereof

Abstract

The invention discloses a pressure balance type plug valve and a driving device thereof. According to the valve and the driving device, when the valve is opened, under the action of driving force, a valve rod of the whole valve can conduct vertically-downward linear motion at first and then rotate by 90 degrees anticlockwise to achieve a full-open state; and when the valve is closed, under the action of driving force, the whole valve can realize that the valve rod firstly performs vertical upward linear motion and then clockwise rotates by 90 degrees to realize a fully-closed state, most friction torque generated between a plug cock and a valve body due to medium force is eliminated in the opening process, the opening and closing torque is effectively reduced, and meanwhile, the current situation that a cock wedge is tighter and cannot be opened due to deformation of the valve body caused by the medium force in the opening and closing process is avoided.

Description

technical field [0001] The invention relates to the technical field of plug valves, in particular to a pressure-balanced plug valve with anti-wedging and low-torque opening and closing and a driving device thereof. Background technique [0002] The pressure balanced plug valve can meet the harsh working conditions of high flow rate, high pressure and severe erosion of gas medium, so it is widely used in the on-off valve of natural gas pipeline system. The valve is switched by rotating the cock by 90°. Under the action of the medium pressure, the pressure of the big end and the small end of the cock is balanced, but due to the difference in area, an unbalanced force of the medium is formed in the axial direction, and the sealant is formed between the cock and the small end. The sealing surface of the valve body forms an oil film with good rigidity to provide the sealing specific pressure and form reliable sealing and lubrication. [0003] Under the action of the medium force...

AI Technical Summary

Problems solved by technology

[0003] Under the action of the medium force, the valve body of the pressure balanced plug valve will undergo rigid deformation from the inside to the outside, and the upward displacement of the cock will increase under the action of the unbalanced force of the medium, especially in the case of fire in the axial direction. The displacement of the valve will be seriously increased, and the wedge between the cock and the valve body will be tighter, resulting in an increase in the torque during the opening and closing process of the valve. At the same time, the sealing surface between the cock and the valve body will be severely worn, which is not conducive to the sealing and service life of the valve.

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