Online welding of flange cracks
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A crude oil pipeline with a pressure of 2.5 MPa was found to have a crack on one of its flanges after it came online; the pipeline could not be shut down. Is it possible to weld the crack on-site?
In theory, there shouldn’t be too many problems when performing welding repairs on pressure vessels or pipes that lack a gas space. However, given such high pressures, caution is necessary. It’s best to address the issue first before proceeding with welding repairs, as safety cannot be taken lightly. Here are some suggestions for you: 1\ It’s possible to fill the pipeline with water; if so, the risk of carrying out welding repairs while the pipeline is filled with water is reduced. 2\ Based on the actual condition of the cracks in the pipeline, consult a manufacturer that specializes in metal reinforcement to see if metal adhesive reinforcement could be an option. 3\ Regardless of the cracks, install a clamp outside the flange where the cracks are located; this way, in case of leakage or failure, the clamp can be used to address the problem
The pipeline cannot be shut down; a pressure of 2.5 MPa can be handled by using a clamp.
Construction is carried out using the pressure substitution method for leak sealing.