Breaking Barriers: In-line Inspection for High-Temperature Bitumen Pipelines
A high-temperature MFL-A solution enables safe and reliable corrosion inspection under extreme conditions
Bitumen is a highly viscous material that cannot be pumped at ambient temperatures. To enable pipeline transport, it must be heated to temperatures typically around 140°C. This heating reduces viscosity and allows the bitumen to flow.
Standard in-line inspection tools are not designed for such high-temperature environments. The electronic components and batteries are often rated at maximum operating temperatures around 65°C. Even moderate exceedance of these limits can lead to malfunction or failure of components critical for data acquisition.
At significantly higher temperatures, the material properties of different critical components begin to shift. For instance, polyurethane cups, commonly used to center and propel inline tools, become softer, which can compromise the tool stability and increase the risk of it becoming stationary in the line.
Due to these limitations, pipelines transporting hot bitumen have traditionally been excluded from regular corrosion monitoring programs. This leaves operators without reliable data on pipeline
condition and increases the risk of undetected wall loss. To eliminate this risk, a client from Canada approached ROSEN to find a solution.
Asset description:
- Nominal Pipe Size: 24 inch
- Maximum Design Temperature: 149°C
- Product: Bitumen
- Distance: 90 km
- Wall Thickness: 9 mm to 11.2 mm
- Bend Radius: 5.0 D
Our Solution
To enable the inspection of the 24” pipeline, a magnetic flux leakage (MFL-A) tool for application in high-temperature liquid lines was developed.
Among various measures, a key feature of the design is the use of a phase change material surrounding the electronics. This material is solid at the start of the inspection. As the tool moves through the hot pipeline, the material begins to melt, absorbing heat from the outside. During this melting process, the temperature inside the tool stays nearly constant, because the heat is used to change the material’s state rather than heating up the electronics. A protective buffer was formed, which shields all sensitive components and ensures continuous data acquisition from launcher to receiver.
Cups and discs were replaced by metal ring brushes and sheet metal discs. These components provided the necessary support and flow resistance to ensure reliable propulsion through the pipeline. In addition, various other parts – such as magnets, adhesives and sealings – were substituted with materials rated for continuous use at high temperatures.
Since its first utilization, the tool has inspected 630 km of pipeline with temperatures up to 147°C and heat exposure time of up to 21 hours.
Your benefit
This solution allows operators to perform corrosion inspections in hot bitumen pipelines – something that was not previously feasible. The tool can be deployed during normal operation, resulting in
minimal impact on production. By enabling regular inspection, it supports early detection of defects, enhances operational safety, and helps maintain the integrity of the pipeline asset. This contributes to improved risk management, reduced downtime, and greater confidence in long-term pipeline performance, ultimately significantly increasing the economic value of the operator’s asset.