Small Companies Make Fast, Non-Destructive Exam of Pipelines Possible

March 2015, Vol. 242, No. 3

The need for reliable, rapid pipeline inspection systems and services is growing as the pipeline network, both domestic and international, ages and expands. Inspection and defect reporting have become time-sensitive as incident prevention becomes a top priority.

Despite mitigations in place along the pipeline, corrosion, material defects and excavation-induced damage are never entirely prevented and can result in pipeline failure, causing numerous costly incidents. Rapid, accurate testing is necessary to prevent disasters and small companies are fit to respond quickly and adapt efficiently wherever quality inspections are needed.

Often, the industry heavily relies on the use of smart-pigs, which collect data from hundreds of miles of pipelines in a single test run, allowing faster acquisition of information. However, analyzing this quantity of data for defects is slow, taking up to nine months. History has shown flawed pipelines may fail during this time.

Fortunately, an alternative is now available using guided waves with a faster reporting rate, and the added benefit of being able to keep the pipeline in normal operation during the inspection.

Accel Inc. is a small and agile company that focuses on the speed of inspection resource deployment, addressing client needs in a timely. Specializing in guided-wave testing (GWT), Accel provides immediate reporting as inspectors move along the pipeline. Major flaws are instantly detected and the results can be directly conveyed to the owner.

GWT uses low-frequency ultrasonic bursts to locate changes in the pipeline cross-section from a single location where a transducer ring is clamped around the pipe. Metal loss such as internal or external corrosion and major defects, as well as all structural features of the pipe are detected and located.

The application of GWT ranges from the inspection of long distances of above ground pipeline – up to 500 feet per shot – to cased, road crossing and buried pipes. GWT can be used at refineries, plants and on unpiggable pipelines. This non-invasive technique is not restricted by the product flow and requires minimal access to the pipe.

GWT was first commercialized in 1999 by Guided Ultrasonics Ltd. (GUL), a U.K.-based company, and developed after exhaustive research carried out by the non-destructive testing group at the Imperial College, London. GUL’s Wavemaker Pipe Screening System© has reached the fourth generation (G4) and was recently miniaturized to improve the portability and accelerate the inspection rate. The 16-channel G4mini is a fully capable G4 in a smaller, lighter package. It can be configured for all pipe and tube applications, including monitoring.

Accel is working with GUL to provide the most accurate integrity assessment of pipelines, refineries and infrastructure quickly and efficiently, assisting owners to prevent potential costly failures.