Out-of-roundness detection method for orifice of large-aperture bend pipe

Abstract

The invention discloses an out-of-roundness detection method for the orifice of a large-aperture bend pipe, and belongs to the technical field of out-of-roundness detection for the orifice of the large-aperture bend pipe. The method comprises the steps that 1) an orifice image of the bend pipe is shot; 2) the orifice image is preprocessed; 3) the maximal diameter and the minimal diameter of the bend pipe orifice are calculated; 4) the orifice out-of-roundness of the bend pipe is calculated; and 5) a suggestion is obtained from a campus. Via the method, the out-of-roundness detecting efficiencyand convenience are improved greatly, fewer people are needed to detect the orifice out-of-roundness of the bend pipe, and the orifice out-of-roundness detection can be more accurate; and at the sametime, the concrete rolling circling frequency and a reference rolling circling value are provided for a bend pipe orifice rolling circling procedure, and the orifice rolling circling frequency can bereduced.

Description

technical field [0001] The invention relates to the technical field of detecting the out-of-roundness of the mouth of a large-diameter elbow, in particular to a method for detecting the out-of-roundness of the mouth of a large-diameter elbow. Background technique [0002] In the pipeline engineering of petroleum, chemical industry, natural gas transmission, metallurgy, nuclear power plant, and heat supply industries, there are a large number of pipe butt welding work such as straight pipes and curved pipes. The out-of-round pipe opening will significantly reduce the welding quality and seriously affect the transmission pipeline. service life. Long-term statistical results at home and abroad show that the failure rate of bent pipes is significantly higher than that of straight pipes. Sustaining and its internal stress will cause the nozzle to be out of round, resulting in unqualified roundness of the nozzle of the elbow. On the other hand, it is related to the pipeline oper...

AI Technical Summary

Problems solved by technology

Under normal circumstances, most of the domestic methods for calibrating the out-of-roundness of large-diameter elbows adopt relatively primitive methods, such as: placing a jack on the edge of the inner wall of the nozzle, and manually operating the top to apply pressure to correct the circle. The out-of-roundness detection method is very simple, mainly using the measuring ruler measurement method, which needs to take different measurement points from the circumference of the nozzle, not only the production efficiency is low, but also the detection results are only qualitative concepts without quantitative conclusions, and the product quality cannot be guaranteed. ensure

The roundness method of this kind of roundness correction method is not only labor-intensive and low in work efficiency, but also directly leads to low production efficiency, cumbersome and complicated procedures, high energy consumption, high labor costs, and low product precision due to backward detection methods. question

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