Non-contact magnetometric diagnostics of potentially hazardous sections of buried and insulated pipelines susceptible to failure

The article considers the non-contact magnetometric diagnostics (NCMD) of buried pipelines. In Russia, China, and other countries, the NCMD is used for gas and oil pipelines, water conduits, heating system pipelines, and other service buried pipelines. The main task of the NCMD is the detection of the potentially dangerous sections of buried pipelines, on which, as a rule, it is impossible to carry out the in line inspection. Based on the 20 years experience in the metal magnetic memory (MMM) method in 2000 Energodiagnostika Co. Ltd. began the development of the NCMD of buried pipelines using the specialized multi-channel highly sensitive flux-gate sensors. The NCMD is based on measurement of distortions of the magnetic field of the earth, conditioned by the variation of the pipe metal’s magnetization in the stress concentration zones and in zones of developing corrosion-fatigue damages. Test results of buried pipelines by the NCMD are presented. A complex diagnostics of buried pipelines based on the NCMD with identification of potentially hazardous segments and subsequent non-destructive testing in prospect holes is offered.