Terminal and pipeline owners are obligated to ensure they are used in safely. This requires an effective inspection and maintenance program. Owners are responsible for developing, documenting, implementing, executing, and assessing pipeline inspection systems and inspection procedures that will meet the relevant requirements.
These systems and procedures typically include:
- Organization and reports of structure for inspection personnel
- Documentation and maintenance of inspection and quality assurance procedures
- Documentation and reports of inspection and test results
- Corrective actions regarding inspection and test results
- Internal audits for compliance with the quality assurance inspection manual
- Review and approval of drawings, design calculations, and specifications for repairs and alterations
Different types of inspection and monitoring methods depend on the circumstances and the piping systems. The main challenge, however, for effective inspections is to ensure the coverage of potential defective areas on very long pipe runs. There are two types of such inspections:
- Pipe screenings quickly cover large sections of pipes and gives a qualitative assessment of their condition and enable identifying where defective areas exist
- Detailed examinations give a quantitative assessment (such as the minimum wall thickness), which is applied to known potential “at risk” areas or areas identified by qualitative assessments
There are a number of techniques for the rapid screening of pipe work. Whether they are applied depends on the size and length of the pipes to be inspected. These techniques include long-range ultrasonic (UT) and magnetic-flux leakage (MFL) testing. MFL, used by such Silverwing products as Pipescan, can be used by relatively unskilled technicians to cover large areas and identify sections for further inspection. Long-range UT is also a quick method, but requires much more skill.
Quantitative Inspection Solutions
The most popular method of detailed inspection is UT, for simple thickness readings or recorded B-scans/C-scans. The manual thickness point method yields accurate readings at the measurement point, but the area covered by UT is small, therefore so is the probability of detection. Automated methods such as RMS2 significantly improve coverage, and thus the probability of detection.