Grinding process of sealing surface of ball valve

Abstract

The invention relates to a grinding process of a sealing surface of a ball valve. The grinding process comprises the steps of rough grinding, fine grinding, ultrafine grinding, and grinding and cleaning of a valve seat and a sphere, wherein a diamond paste and an engine oil mixture are adopted in the rough grinding, the particle size phi of the selected diamond paste ranges from 40mu m to 10mu m, so that the scratch removal and sphere rounding can be realized; in fine grinding, a diamond paste, kerosene and a microcrystal graphite mixture are adopted, the particle size phi of the selected diamond paste ranges from 7mu m to 5mu m, so that the primary mirror surface effect can be achieved; in the ultrafine grinding, a diamond paste and a microcrystal graphite and kerosene mixture are adopted, the particle size phi of the selected diamond paste is smaller than 5mu m, the rotating speed of the sphere is controlled to be below 5rpm to achieve the mirror surface effect, and finally the kerosene is coated on the sphere and grinding cleaning are performed to achieve a better mirror surface effect. The sphere ground and the sealing surface of the valve seat can achieve the mirror surface effect, the surface roughness can achieve Ra0.02-0.005, the operation torque is low, the service life is long, the valve seat can be adsorbed on the spherical surface of the sphere, and no leakage exists under the trial pressure of low-pressure nitrogen being 0.6Mpa.

Description

technical field [0001] The invention relates to the field of valve manufacturing, specifically a ball valve manufacturing process, more precisely a grinding process for a sealing surface between a ball valve seat and a ball. Background technique [0002] The sealing surface between the valve seat and the ball in the ball valve is processed by grinding process, the smoothness of the sealing surface between the valve seat and the ball, and the degree of fit between the valve seat and the ball directly affect the sealing performance between the ball valve seat and the ball , valve opening and closing operating torque and valve service life, etc. The roughness of the sealing surface between the valve seat and the ball obtained by the existing grinding process is Ra0.15-0.2, and the degree of fit between the valve seat and the ball is tested: there is a small amount of leakage in the low-pressure nitrogen test at 0.6Mpa, and it can be detected by the naked eye. It is directly ob...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the defects of the sealing surface smoothness and fit between the valve seat and the ball existing in the prior art, the purpose of the present invention is to provide a ball valve sealing surface grinding process, so that the sealing surface of the valve seat and the ball appear matte (whitening). or gray) or a mirror effect with a higher finish, and a good fit between the valve seat and the ball, greatly reducing the friction coefficient between the valve seat and the ball, with good sealing performance of the ball valve, easy opening and closing operation and long service life The advantages

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