Thermal image detection for corrosion defects of pipeline valves
                                                                          DING Jichao, HE Lidong, ZHANG Lihao
(Beijing Key Laboratory of Health Monitoring and SelfRecovery for High end Mechanical Equipment,Beijing University of Chemical Technology, Beijing 100029,China)

Abstract: In order to detect the corrosion phenomenon of the inner wall of coal chemical valve online, the flow field analysis software was used to simulate the fluidsolid coupling flow field of the coalwater slurry ball valve, and the characteristics of the valve flow field were analyzed, and then the infrared thermal imaging method was excited by the electromagnetic coil. An online test bench was constructed. The thermal imaging principle of the defective steel plate was analyzed, and the valve and pipe defects were prefabricated and carried out. The results show that the erosion of the valve is most likely to occur in the inner surface, as the metal seal ring of the inlet and outlet and the valve body surface in the vicinity, and the corrosion defects of the valve and the pipeline can be detected by infrared imaging nondestructive testing. The coil excitation time is longer, the excitation current is larger, and the defects is easier to be detected. The Utype defects are easier to be detected than the Vtype defects.

Key words: pipeline valves; erosioncorrosion; flow field analysis; electric magnetization; infrared thermal imaging detection