Underwater crossings inspection, including diving

Underwater crossing inspection program

Pipeline underwater crossing inspection includes the following steps:

1. Underwater crossing technical documentation review and analysis.

2. Ground reconnaissance to identify specifics of the pipeline laying, soil nature and the type of river banks in the water crossing area.  

3. Verification of the underwater crossing actual technical condition compliance with standards and technical documentation requirements.

4. Block valves, flanges and welds condition assessment.

5. Measurement of pipe – ground spontaneous and imposed potential in the underwater crossing shore area before and after DC power is supplied to the pipeline.

6. Evaluation of the pipeline coating condition in the water crossing area.

7. Underwater crossing diving inspection:

• Visual inspection of all pipeline underwater section length;
• Visual inspection results photo and video record for all pipeline underwater section length;
• River bed profiling and pipeline depth identification;
• Test areas excavation;
• Inspection of coating condition in the test areas;
• Test areas visual inspection and pipe wall thickness measurement;
• Defect location and defect nature identification in the test areas;
• Repair of inspected areas coating.

8. The results review and consolidation, reporting materials development.

9. Issuing the pipeline underwater crossing industrial safety conclusion.