Pipeline inspections with ‘smart pig’

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Decommissioning pipelines or invasive tasks like demolition and excavation work can make pipeline inspections time consuming and expensive. The Limburg Water Authority (WBL) recently introduced a non-destructive pipeline inspection method, so-called ‘pigging’, which determines a pipeline’s remaining lifespan while it is still in operation.

Data from the inspections will provide WBL with insight into the operational reliability, the remaining lifespan and planning of any replacement. Considering the major investments involved in replacement, this information is extremely useful.

WBL has enlisted Witteveen+Bos to provide support and supervision of pipeline inspections. This involves the employment of a smart inspection ‘pig’ (pipeline inspection gauge): the Acquarius. The technology was developed by Acquaint, one of the few companies in the world carrying out this unique procedure.

Working method

The non-destructive inspection method works as follows: a launching device is installed for the insertion of the inspection pig. For this, the pipeline is first cleaned by passing a foam plug through the pipeline twice. A test run is then carried out, followed by the inspection.

The pig is fitted with a transmitter that enables it to be tracked above ground. Because the pig is propelled at a fixed speed, we are able to gain initial insight into the location of any obstacles in the pipeline during the inspections.

The pig performs an analysis of the pipeline’s condition by measuring, among other things, wall-thickness deterioration, location, corrosion, leaching, diameter and H2S degradation. Prior to the runs, water must be preserved to ensure sufficient volume to propel the pig through the entire pipeline in one go. Based on the buffer plans, which provide insight into the system’s buffer capacity, we can determine how much water can be preserved to prevent overflow.

Successful implementation

Following extensive preparations, the project team started the pipeline inspections in the last week of June 2022. The first pipeline to undergo successful inspection was the section between Belfeld and Tegelen. And it also provided a lot of useful data. Witteveen+Bos will continue to support WBL until the end of 2023 in carrying out inspections of a large part of the concrete and/or asbestos cement pressure pipelines throughout the province of Limburg. Acquaint will carry out the inspections together with the contractors Van den Heuvel and Van der Ven.

Custom solutions

Project responsibilities of Witteveen+Bos include supporting WBL in general technical coordination, inspection planning, drawing up buffer plans for each section of pipeline, drafting action plans for the inspections, issuing work permits and supervising the inspections.

Together with WBL and the contractors, we will assess the most effective way (see Total Cost of Ownership) of executing the inspections and weigh up the various possible solutions for both launching and receiving installations. This involves providing custom solutions that ultimately lead to choices being made for the type of implementation required for each section of pipeline.

The inspections are prepared and carried out based on a construction team approach. WBL will ultimately use the results of the inspections to develop and optimise its management plans and processes. Witteveen+Bos will also play an advisory role in this in a later phase of the project.