Pipecare Group enhances crawler technology for inline pipeline inspection

Pipecare Group has enhanced its advanced crawler- based inline inspection (ILI) technology designed for challenging pipeline environments, particularly no-flow, unpiggable and pre-commissioning pipelines. The system has been developed and tested across multiple sizes ranging from 8 to 56 inches, with configurations that support either tethered operation—using reinforced cables for power and control—or fully autonomous battery-powered systems with remote control, depending on pipeline length and operational requirements. This paper presents the system architecture, operational capabilities, and technical specifications of the crawler platform, with emphasis on corrosion detection, wall thickness measurement, and geometric assessment in constrained pipeline conditions.

Pipeline inspection technologies have evolved to address the limitations of conventional pigging systems, especially in pipelines that are inaccessible due to geometric complexity or operational constraints. In this context, Pipecare engineering teams have developed complementary solutions: the self-propelled Ultrasonic Wall Measurement (UTWM) Crawler and the Crawler–Caliper tool. These systems integrate mechanical mobility, advanced sensing technologies, and onboard data acquisition to deliver reliable inspection results in complex environments.

UTWM Crawler: Design and operational capabilities

Pipecare’s UTWM crawler is a tethered, self-propelled inspection system designed to operate in low-pressure or no-flow pipelines without requiring product flow. Its modular design incorporates a high-torque motorized tractor, a UTWM sensing module and a control unit. The tractor is equipped with motorized wheels and a spring-loaded suspension system to maintain continuous contact with the pipe wall, ensuring stable traction and controlled movement through bends and diameter variations.

Power and control signals are transmitted via a reinforced tether cable connected to an external control unit. The UTWM module utilizes an array of ultrasonic sensors arranged comprehensively to capture high-resolution wall thickness measurements. Data are recorded onboard during operation and retrieved after the inspection for detailed analysis. The system has proven able to inspect pipelines with an outside diameter of 8 inches (219.1 mm) and can overcome restrictions as small as 151 mm in straight sections, corresponding to a 69% diameter reduction. It is designed for wall thickness ranges between 15 mm and 34 mm, with optimal measurement performance up to 25 mm under standard conditions. The UTWM system provides an axial resolution of 3 mm and improved surrounding resolution, enabling accurate detection and quantification of corrosion, metal loss, and wall thickness variations. Its ultrasonic technology ensures reliable data acquisition, particularly in liquid-filled pipelines.

Crawler–caliper tool for geometric inspection

Complementing the UTWM system, Pipecare’s Crawler–Caliper tool is designed for detailed geometric inspection of unpiggable pipelines. It is also suitable for pre-commissioning applications without requiring the pipeline to be filled with high-pressured air or nitrogen, offering a more efficient and cost-effective alternative to conventional methods. The system operates autonomously using onboard batteries and advanced electronics, ensuring reliable performance in challenging pipeline environments.

Pipecare Group’s enhanced UTWM Crawler

The crawler employs independently driven motorized wheels with integrated control units, providing strong traction and manoeuvrability. Each wheel is equipped with an independent suspension system featuring a single-arm design with spring and shock absorption, enabling stable navigation over uneven internal surfaces while maintaining continuous wall contact. The Caliper module incorporates multiple arranged arms and sensors to capture high-resolution geometric data, including pipe diameter, ovality, dents, buckling, and other deformations. This allows precise identification and characterization of structural anomalies affecting pipeline integrity. All measurements are synchronized with positional track- ing data, ensuring accurate defect localization.

Operationally, the system can navigate pipeline sections with diameter reductions of up to 85% in straight segments and cross bends with a minimum radius of 1.5D. It is designed for pipelines up to 56 inches in diameter and operates in atmospheric air. The crawler is capable of long-distance travel on a single battery charge and uses an electric traction system with brushless motorized wheels constructed from durable materials to ensure reliable performance and wear resistance.

Technology Readiness and Deployment

Both the UTWM crawler and the Crawler–caliper tool represent mature, field-validated technologies. The UTWM system, in particular, has been successfully deployed in 8-inch operating pipelines, demonstrating reliable performance under real and complex conditions. Pipecare operational team has commercially deployed the technology with high levels of customer satisfaction. Its scalable design also allows adaptation to a broader range of pipeline sizes.