Identifying defects in natural gas transmission/distribution pipelines as infrastructure facilities of the country is one of the most important and challenging cases in the gas industry. Therefore, it is necessary to have a technique for a comprehensive inspection of the existing pipe infrastructure and prevent catastrophic failures and environmental risks. The most important natural factor that causes external destruction of steel pipes is external corrosion. The PCM method is one of the modern methods of inspecting the quality of pipeline coating and its accurate diagnosis. In this project, the design and construction of steel pipe coating fault finding (PCM) device is considered.