Abstract: Hot tapping is a common maintenance and repair method for steel oil and gas pipelines. This method uses mechanical tools to cut pipes, which will inevitably produce residual iron chips. With the long-term operation of oil and gas pipelines, the iron chips in them will have great impact on the purity of the oil and gas medium and the switch of the valve on the pipelines. In this study, a folding and rotating magnetic adsorption device for iron chip recovery with walking wheel was developed. Through many tests and improvements, the problem of residual iron chip recovery after hot tapping was successfully solved, and the harmony between oil and gas pipeline maintenance and repair operation and subsequent operation and maintenance was improved in terms of safety.

Key words: hot tapping, residual iron chips, iron chip recovery, magnetic adsorption