Pipe Inspection with Long Range Ultrasonic (LRUT) for ST1

Pipe Inspection with Long Range Ultrasonic (LRUT) for ST1

ST1’s refinery in Gothenburg needed to find out whether a crude oil pipeline could be safely used in the future. The Long Range Ultrasonic (LRUT) method of testing was the answer.

Safety top priority

At a petrochemical plant it is essential to maintain a high level of safety by inspecting the pipelines regularly.

“All our work is based on creating maximum safety,” comments Magnus Nylander. He is Head of Inspections at the ST1´s refinery in Gothenburg. One fifth of Sweden’s total demand for oil products is processed there each year.

Avoiding expense and disruptions

The two-kilometre-long, insulated, 20-inch pipeline carries heavy oil from the port of Skarvikshamn to the ST1 refinery. As the pipeline rests directly on pipe supports, it is difficult to inspect.

For safety reasons, ST1 replaces exposed pipelines that cannot be inspected, every twelve years. To avoid unnecessary expenses and disruptions to production by replacing a functional pipeline, ST1 contacted Kiwa Inspecta for help.

Testing during production

Kiwa Inspecta found that the pipeline could be inspected using the LRUT method of scanning.

LRUT is suitable for inspecting pipes that are not easily accessible. When using this method it is only necessary to remove the insulation at the measurement points. A collar outside of the pipe transmits signals reaching at least 25 metres in each direction. Low-frequency ultrasonic pulses show if the pipeline has any weak spots and, if so, where they are.

Kiwa Inspecta assumed full responsibility for the entire operation. It took about three weeks and was performed while the refinery was operating at full capacity and the oil pipeline was being used as normal.

Vital answers at reasonable price

“Kiwa Inspecta’s tests gave us clear information that our crude oil pipeline is in good condition and that it will continue to do its job,” remarks Magnus Nylander at ST1. “With LRUT we can maximise the life of the pipeline in a cost-effective way.”

“I am convinced that there are many pipelines in other industries where this technology will provide vital answers at a reasonable price in the future,” Magnus Nylander concluded.