In-service long-distance transport pipeline girth-weld defect magnetic-particle detection mechanism and detection method

Abstract

The invention discloses an in-service long-distance transport pipeline girth-weld defect magnetic-particle detection mechanism and a detection method, and relates to the technical field of non-destructive inspection of butt welds. The mechanism comprises a central pipe, fixed bases and rotary mechanisms; the fixed bases fixedly sleeve two ends of the central pipe; the rotary mechanisms rotatably sleeve two ends of the central pipe; the two fixed bases are each installed with a travelling wheel; an installation frame is also connectedly arranged between the two rotary mechanisms; a cleaning device, a high-definition visual acquisition device and an automatic magnetic powder detection device are uniformly installed in the circumferential direction of the installation frame at intervals; anda weld identification probe is also fixedly installed on the head part of the central pipe. According to the in-service long-distance transport pipeline girth-weld defect magnetic-particle detection mechanism and the detection method in the invention, a girth weld is automatically identified, propelled and located; furthermore, axial rotation is carried out, so that deviation scanning confirmationon the weld is carried out; furthermore, attitude adjustment is carried out through the lifting mechanism of the travelling wheel; therefore, the weld and the rotary mechanism are precisely located;guarantee is provided for next detection; furthermore, the applicability is high; and the effect is the best.

Description

technical field [0001] The invention relates to the technical field of non-destructive flaw detection of butt welds, in particular to a magnetic particle internal detection mechanism and detection method for girth weld defects of in-service long-distance pipelines. Background technique [0002] According to the study of fatigue defects, it is of great significance to make the initiation and expansion of fatigue cracks, and fatigue damage often occurs under the stress state of the load lower than the allowable value, and sudden brittle fracture occurs, and there is no obvious plastic deformation before fatigue damage, which is not easy It is perceived that the current magnetic flux leakage detection technology cannot detect the state of stress concentration before the crack, so these defects often bring unexpected catastrophic accidents to people. In recent years, there have been many weld cracking accidents in oil and gas pipelines, among which there were also attempted crac...

AI Technical Summary

Problems solved by technology

[0003] More than 80% of the defects of long-distance pipelines are in the butt girth weld of the pipeline. The detection rate and identification rate of the traditional domestic and foreign non-destructive inspection methods are low (<60%), which is far from meeting the needs of production. Operational needs, for this reason, it is inevitable to carry out individual defect detection on this girth weld

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