For over 60 years, intrusive pig signalling has been the standard in pipeline operations. Intrusive pig signallers provide a mechanical method for detecting the passage of pigs and work by triggering a flag or electrical indicator when the pig passes and they often require manual intervention for maintenance and resetting. However the increasing demand for safer, more efficient and environmentally friendly operations has driven innovation in pig signalling technology.
Non-intrusive pig signallers operate without penetrating the pipeline instead relying on technologies such as magnetic, acoustic and ultrasonic to detect pig passage. In this article, we will highlight the reasons why the industry is making the switch to non-intrusive solutions. Whether driven by the need for cost-effective options, environmental considerations or the push towards automation, non-intrusive pig signallers are increasingly seen as the future of pipeline monitoring.
Intrusive Pig Signallers – Key Limitations and Risks
Complex and Lengthy Installation
As their name suggests, intrusive pig signallers intrude into the pipeline and this requires extensive planning and skilled labour and installation can be a lengthy process. Typically, it will involve hot tapping, welding and pressure testing and specialised equipment may be required. The installation process also typically requires work permits, increasing the complexity of the project.
Safety and Environmental Challenges
The biggest safety concern with intrusive pig signallers is pressure. Even signallers that are designed to be removed under pressure can be extremely dangerous if this process is not carried out correctly. Additionally, intrusive signallers increase the risk of leaks, posing a risk to workers and the surrounding environment.
Hidden and Ongoing Costs
Whilst the upfront costs of intrusive pig signallers might appear similar to non-intrusive models, the hidden costs associated with their installation such as specialised equipment and skilled workers are often substantial. Additionally, any maintenance or repair work can be expensive and time-consuming, often requiring significant downtime and/or qualified technicians to ensure safe operating conditions.
Lack of Precision and Flexibility
Intrusive technology has become less effective with the advancement of modern solutions. They often lack the flexibility and precision now required and they can suffer from issues such as high failure rates due to the wear and tear of the seals and other components. Since the signaller trigger is inside the pipeline, any failure may not be immediately obvious to operators and pig passages may be missed. Additionally, without an automatic reset function, intrusive signallers rely on operators manually resetting the signaller flag, a step that can be overlooked, leading to uncertainty about future pig passages.
Longer Lead Times and Delays
Intrusive signallers are often customised to fit the specific requirements of each pipeline, which introduces several challenges. The manufacturing process can be more complex and time-consuming, leading to longer lead times. Without proper planning, projects or replacement signallers may face delays.
How Non-Intrusive Pig Signallers Overcome These Challenges
Ease of Installation and Maintenance
Unlike intrusive signallers, non-intrusive signallers can be quickly and easily mounted onto and removed from the pipeline using ratchet straps or stainless steel banding for permanent installations. This process takes just minutes to complete. Maintenance requirements are minimal further reducing downtime and operational costs. Additionally, they provide greater flexibility as they can be easily repositioned on the pipeline.
No Penetrations, No Leak Paths
Non-intrusive pig signallers eliminate the safety risks associated with pressure handling, as they do not penetrate the pipeline. This makes them inherently safer, removing the dangers of removal or maintenance under pressure. Additionally, their design minimizes the risk of leaks, protecting both workers and the surround environment from potential hazards.
Discover the risks associated with intrusive pig signallers in our blog post, “Non-Intrusive vs. Intrusive Pig Signallers – Health and Safety, Employees and Your Community.” Learn why this technology might not be the best choice and what alternatives are available.
Lower Costs, Higher Efficiency
Non-intrusive pig signallers are more cost-effective in the long term. They eliminate the need for specialised equipment, skilled labour and complex installation processes, significantly reducing upfront expenses. Maintenance is also simpler and less frequent, minimizing downtime and associated costs. With fewer operational disruptions and lower ongoing expenses, non-intrusive signallers offer a more economical solution over their lifespan.
Smarter, More Capable Systems
Non-intrusive signallers log pig passage data information for future review and provide detailed insights which can be accessed directly on the unit display or through a dedicated software. For example they can capture the magnetic signature of a passing pig, offering valuable data for analysis and troubleshooting. They also avoid the wear and tear issues common in intrusive models, ensuring consistent performance without the risk of missed pig passages due to undetected failures. Automatic reset functionality eliminates the need for manual intervention, reducing the chance of human error. These advancements provide greater confidence and accuracy.
Integration with Modern Pipeline Control Systems
As well as providing local indication of pig passage on the signaller’s display, non-intrusive units can transmit signals remotely through various methods including RS485 MODBUS, LoRaWAN, Bluetooth or satellite. This integration provides operators with real-time indication without needing to be present at the signaller’s location, enhancing efficiency and flexibility.
Learn more about the technological limitations of intrusive pig signallers in our blog post, “Non-Intrusive vs Intrusive Pig Signallers – Improved Confidence and Data for Modern Pipeline Control.”
Versatility & Flexibility
Non-intrusive models are generally versatile and adaptable, with a range of technologies available to suit different pipeline needs. While these technologies offer flexibility, it’s important to note that each type has its own limitations. For example, ultrasonic units are only suitable for liquid lines whilst others only detect magnets. However, even with these constraints, they be easily deployed across a variety of pipelines compared to intrusive models. Their standardised design leads to faster production and shorter lead times, making them a more efficient option for both planned projects and unexpected requirements.
Conclusion: A Smarter Choice for Modern Pipelines
Non-intrusive pig signallers address the limitations of traditional intrusive models and are a safer, smarter and more efficient option. They remove any risk associated with pressure during the installation and maintenance of the units as well as removing potential leak paths. They offer greater flexibility with the ability to quickly and easily move the units around the pipeline. With advanced remote communication, logging and reset options, pig passage data can be accessed without needing to be physical close to the pipeline. As the industry increasingly prioritises environmental impact, safety and operational efficiency, non-intrusive signallers are the standout option.
If you are considering making the switch to non-intrusive pig signallers and would like additional information, our team is here to help. Contact us today for trial options or further support.
