Corroded areas on pressure equipment need to be repaired or assessed before further service can be considered. Current methods usually involve using tools like bridging bars, pit gauges and ultrasonic probes on a coarse manual grid. These methods are time consuming and sensitive to human error. In pipelines, where in-line inspection (ILI) runs may find hundreds of corroded areas, these methods may lead to lengthy and expensive projects that yield results inspiring less than the required level of confidence.
Applus+ RTD has been a pioneer in applying laser profilometry in the field and has several different inspection systems in use that are tailored to specific inspection situations.
LPIT is an inspection system that is tailored to follow-up investigation after ILI runs on pipelines. It consists of an automated system that scans the full pipe circumference, taking over 600 readings per square inch. An exact replication of the pipe surface can be produced in this way. The system enables reporting in the field, and initial analysis according to RSTRENG. The results of these measurements can be analyzed according to FFS codes like API 579, BS 7910 and ASME B31G.
Applus+ RTD's Handyscan system is a less application-specific tool. It is the most portable laser profiling tool in use today and offers the flexibility needed in order to take laser profiles in and around plants, pipelines and storage tanks. The system weighs just over one kilo and outputs images in the more common 3D data formats. A unique feature of Handyscan is that it is self-positioning, meaning that no fixed reference points are needed to take a laser profile.
The key benefit of Laser profilometry is that it can obtain highly accurate data in a timeframe unmatched by any other method. To obtain the most out of these results however, they need to be subjected to appropriate analysis.
LPIT and Handyscan results have been used to calibrate the results of ILI runs. For this purpose, the results of the ILI run and the laser profile are analyzed using Applus+ RTD’s Lasersure software. The improved reliability can be used to eliminate unnecessary digs.
Applus RTD has in-house capabilities for performing level 3 and finite element analysis, worldwide.