Background: Job Overview
As per the Client’s inspection/maintenance team, their major concern was to detect suspected crack/s in the Insulated Pipelines.
The Acoustic Emission Testing (AET) of insulated pipelines was performed whilst operating at high temperature by Arise Global Pte Ltd
- High frequency Sensors were mounted using high temperature waveguides on the pipeline surface. This allowed appropriate sensitivity and reliability of installation.
- Data was collected/monitored only at maximum operating pressure due to operational constraints.
- AE signal detection was performed in threshold mode for crack/stress activity detection.
- AE data recorded during the examination was analyzed using detailed multistage corroborative analysis procedures in time and frequency domains.
Inspection Equipment Details
| Pipeline No | XXX |
| Pipeline Length | 40.79m |
| Pipeline Diameter | 20” |
| Thickness | 12.7 mm |
| Material | ASTM A 358 Gr. 316/316L |
| Built Year | 2010 |
| Operating Pressure during inspection | 18.5 bar |
| Operating Temperature | 46-85⁰C |
| Last Cleaning/Repair Date | NA |
Testing Equipment Details
AE Examination
The sensor arrangement on the pipeline is as shown in Figure below.
AE Inspection Results Analysis
Sample Source Localization Diagram and Table for Insulate pipelines
Conclusion
As per the analysis, the following are the findings around the structure of the pipeline:
- Sustained crack activity near to AE sensor 5.
- Minor crack activity near to AE sensor 2
Overall Pipeline condition grading is determined as ’D’.
Recommendations
A repeat AE inspection of the pipeline should be carried out within 6 months to monitor growth of significant crack activiites observed.
Comments
Once suspected cracks were confirmed by acoustic emission inspection, client replaced the affected pipeline segments.
