After 25 years of service, MAGREB-EUROPA gas pipeline has required some repair in a few pipe joints.
The challenge: being able to repair the pipes while the gas pipeline kept working full capacity. Assurance of the pipeline and personnel integrity was of main concern in this challenging application.
Pipeline Characteristics: Diameter 48″, Pipe wall thickness 21 mm, Steel quality API 5L-Gr 70, Gas flow 1.265.000 KNm3/h, Pressure 72 bar.
The owner of the pipeline trusted SOLYSOL-ARCTECH knowledge and experience for the full turn-key repair of the pipe damaged sectors:
- Development and qualification of welding procedures
- Supply of curved steel, same pipe outside diameter, same base steel 25 mm thick, conformed to wrap the damaged pipe sectors
- Delivery of welding and induction heating as well as electrodes and auxiliary equipment to carry the full repair of the damaged sectors
- High experienced welders qualification for the safe execution of the job, being fully respectful of the qualified welding procedures
- Execution of the repair, sector after sector. Total 4 sectors being repaired, with no defects after NDT according project requirements. First, getting the qualified minimum preheating temperature. This step was quite challenging due to the high gas flow and pressure inside the pipe while trying to reach and maintain the temperature of 100ºC. Then, after temperature is stable in the full area to be welded, we proceed with welding of a surfacing bed on the edges of the curved tiles, then 2G position closing tiles welding to conform a wrapping pipe around the damaged original pipe. Then fillet welding of the edges of the pipe all around the perimeter of the curved tiles.
- Assistance for the safety of personnel and integrity of the pipeline while the repair job was executed. Design and manufacturing of the auxiliary elements to be integrated in the tiles that would wrap the pipe sectors around, so welding on think pickled steel areas would be safe.
- CONCLUSION: full execution of the job, in a safe manner. The gas pipeline kept working at full capacity during the whole repair operation. This repair is considered a permanent repair: the repaired parts would have same guaranty as if the repair sectors would be original pipe.
