[Article Sharing] Intelligent Pig

Ultrasonic Intelligent Pigging | Dacon

Source: http://www.dacon-inspection.com/services/pipeline-services/pipeline-inspection-intelligent-pigging/

Ultrasonic Testing (UT) Intelligent Pigs measure pipe wall thickness and metal loss by direct measurement of the thickness of the pipe wall.

Dacon is an expert in pipeline pigging and specializes in using Ultrasonic Intelligent Pigging tools to inspect 'unpiggable' pipelines. UT Intelligent Pigs are preferred for their smaller size, lighter weight and easier mobilization when it comes to hard to access pipelines or those with no launching and receiving facilities and if the length of the line permits then UT is the preferred option for its higher accuracy and cheaper cost for the customer compared to MFL.

The system contains a horizontally placed transducer contained within the center body of the pig. The transducer sends it sound wave forward where it hits a 45° rotating mirror which then directs the sound wave perpendicular on to the pipe wall. From the inner pipe wall the next signal will travel to the outer pipe wall. Every time the signal hits a surface it will bounce back the same way it came allowing the computer to calculate the time of travel. This time of travel is then converted to distance and measurement exists.

Ultrasonic Testing is not suitable for very thin pipe wall thickness but for all practical purposes this is not relevant for the type of pipelines typically being inspected in the upstream, midstream and downstream oil and gas industries. UT tools work well with the vast majority of pipe wall thicknesses found in the oil and gas industry.

As the technique requires a liquid couplant through which the pulse can travel there must be a liquid in the pipeline although by using batching techniques where a liquid slug is sealed between 2 high sealing pigs it is possible to inspect gas pipelines with UT intelligent pigs.

The advantage of Dacon's UT Intelligent Pigs is the ability to provide a highly accurate value for local wall thickness whilst being lightweight, small and easy to mobilize. With such high accuracy ultrasonic tools can be used for comparing actual wall thickness with nominal wall thickness, verifying previous inspections, fitness for service evaluations and baseline surveys.

Dacon's UT Intelligent Pigs can be used to inspect pipelines that are;

• Carbon Steel
• Austenitic Steel
• High Density Polyethylene (HDPE)
• HDPE Lined
• Risers
• Of Any Diameter From 4" to 64"
• Subsea or Above Ground
• Bare, Coated or Insulated