Release without ignition from a refinery pipeline

During a patrol, an operator detects a hydrogen leak in a refinery on a footbridge 30 meters high. The origin of the leak is identified 4 days later on a pipe under insulation. The operator proceeds to remove the insulation (under SCBA). The leak is located at the level of a reinforcing saddle.

The installation is shut down and put under nitrogen. Thickness measurements and radiographic checks are used to characterise the nature of the crack defect. A leak sealing system (SOFM) is put in place while awaiting the removal of the pipework for assessment during the next shutdown.

The INITIATING cause of the leak was a crack defect on the reinforcing saddle of a hydrogen pipe.
No detailed is known on the failure mechanism.

hydrogen pipeline