A pipeline's most critical defects are the ones that cannot be seen from outside. Internal corrosion, external corrosion beneath coating, mechanical damage, and manufacturing anomalies in the pipe body and welds are invisible to external survey — and dangerous to miss. Inline inspection using intelligent pig technologies is the only method that provides 100% volumetric coverage of the pipeline wall from within the operational flow, without interrupting product delivery.
ILI Technology Selection
MFL Pigging — Metal Loss Detection
Magnetic flux leakage pigs magnetise the pipe wall to saturation and
detect the flux leakage field at areas of reduced wall thickness — from
internal and external corrosion, mechanical dents, and manufacturing defects.
MFL is the industry-standard technology for metal loss survey in carbon steel
pipelines, providing reliable detection and sizing of general and pitting
corrosion across large pipeline diameters and distances.
Ultrasonic ILI — Crack Detection and Precise Sizing
UT intelligent pigs deploy transducer arrays that transmit and receive
acoustic pulses through the pipe wall — providing direct remaining wall
thickness measurement, precise metal loss sizing, and detection of axially and
circumferentially oriented cracking that MFL cannot reliably detect. UT ILI is
required for crack assessment in high-pressure, high-consequence pipeline
systems.
Combined and Complementary Deployment
For pipeline systems requiring comprehensive characterisation — metal
loss, crack detection, and geometry in a single programme — MFL and UT
technologies can be deployed in sequence or combination, providing a complete
picture of internal condition and remaining life.
Pre-Inspection Pipeline Cleaning
The accuracy of any ILI inspection depends
on the condition of the internal pipe surface. Scale, wax, debris, and
biofouling attenuate UT signals and mask MFL anomaly responses — introducing
the risk that a significant defect is misclassified or missed. Our
pre-inspection cleaning services — mechanical pigging, chemical cleaning, and
high-pressure water jetting — prepare the internal surface to the condition
that the inspection technology requires.
Programme Design and Execution
An ILI programme begins with pipeline data gathering — diameter, wall
thickness, operating pressure, product type, bend radii, valve clearances —
followed by tool selection, launcher/receiver review, and operational procedure
development. Altair manages the complete programme from pre-inspection data
review through pig run execution, data analysis, and final reporting.
ILI reports include full pipeline feature lists with location, anomaly
classification, sizing, and priority ranking based on ASME B31G, RSTRENG, or
DNV-RP-F101. Dig lists for field verification are provided with GPS coordinates
and required repair disposition. All data is delivered in formats compatible
with pipeline integrity management databases.