Leak test of pipelines

ALARM – detecting and registering pig

Transporting water-contaminating liquids in pipes and pipelines, such as, for example hydrocarbon products, involves a high risk for the environment. When there is a leakage on such pipes this leads to product loss and environmental damage.

While the use of intelligent pigging systems enables a comprehensive status assessment of such pipe systems, they cannot prove the pipes’ technical leakproofness.

Together with OMV AG,
TÜV AUSTRIA Italia developed “ALARM”:
an intelligent pig to detect leakages by means of AT

Through AT, the acoustic signals coming from leakages are detected and recorded by sensors. Since acoustic signals weaken when moving away from the source, it is hard, expensive and sometimes impossible to record Acoustic Emission through fixed sensors. In case of shorter pipe systems with a maximum of 800 meters, the acoustic signals can be analyzed once they have been received by sensors permanently fixed onto the pipe system’s exterior. This AT procedure based on cross-correlation technique is successfully applied by TÜV AUSTRIA. ALARM has been used for the inspection of a significant number of pipes.


  • Intelligent Pig is completely self-sufficient and does not require any connecting or power supply cables. The case includes sensors for the data acquisition, processing and storage.
  • During normal operation the autonomous pig is transported through the pipe with the transport medium and can be used for between 24 and 100 hrs, depending on its size.
  • The available dimension ranges for the pipe diameter are between 100 mm and 450 mm (4”-18”).
  • High location accuracy: 0,5% of the distance between the nearest artificial and natural markers.
  • Recording of pressure and temperature curves along the entire length of pipe.