Research On Detection Evaluation Technique Of Rigid Polyurethane Foam Insulating Layer For Buried Pipeline

In the transport process of crude oil and heavy oil, when the oil of temperature lower, this will cause solidifying of oil and make huge great damage. So the buried pipeline was not only anticorrosion but also heat insulation, to prevent solidifying of the oil and increase efficiency of transport. According to the background, the failure mode, combinatorial inspection technology and failure evaluation criterions of rigid polyurethane foam anticorrosion insulation layer were systematically studied.This paper analyzes the major failure mode of rigid polyurethane foam anticorrosion and heat insulating layer, and get the failure tree model. Through failure tree analysis (FAT) model realize quantitative analysis of failure mode. Furthermore various countermeasures against the failure were proposed.Every kind of detection technic of anticorrosion and heat insulating layer of principle, merits and faults and characteristic of detection instruments for corrosion protection for pipeline are analyzed. The applicability of coating detection for buried steel pipeline in applying different technical methods was defined according to relational instrumental data, engineering practice and field experiment. Directed toward the particularity (anticorrosion layer+heat insulting layer+ protective layer) of anticorrosion and heat insulating layer, combinatorial inspection technology of buried steel pipeline is raised.The experiment platform is set up in the laboratory. Simulated the corrosion rate of pipeline for variant Rg of anticorrosion and heat insulating layer, and relate to engineering data analysis, anticorrosion failure criterion was eatablished. Using ANSYS simulation analysis, thermal failure criterion and mathematic model was also got. According to engineering data analysis, and correlation study with experiment data, the correlation analysis of between defect condition and detection parameter of anticorrosion and heat insulating layer were done. The detection appraise parameter and data domain were gave.The evaluation system of anticorrosion and heat insulating layer was built. Its main functional modules and implementation techniques in detail were introduced. According to detect evaluation system, the software system is applied in the engineering, the result shows that the detect evaluation system is reliable and useful.