The study on seal detection of high pressure flange based on metal magnetic memory technology

High strength flange are widely used in the petroleum and petrochemical industries, flange seal failure may lead to leakage and unexpected incidents. Currently, the flange seal detection in-service lacks an effective method. A lot of tests to study magnetic force behavior and characteristics of flange bolts have been conducted. In test, the bolt axial, radial magnetic field under the tensile stress is analyzed, and force magnetic models for high strength bolt with four different materials are established. Furthermore, an effective detection method for flange seal based on the results of stress detection of bolt has been presented in this paper.