What Is Pig Tracking?
The term ‘Pig Tracking’ basically means monitoring the location in a liquid processing system of a pipeline pig (or pigs). Pig tracking is important because, to operate and control any pigging system safely, effectively and efficiently, it’s critical to know the whereabouts of the pig within the pipe at any given time.
HPS Pigs are typically used in pipelines with diameters of between 25 mm (1-inch) to 200 mm (8-inches). They’re deployed in a wide range of applications; from food and drink to household products, personal care, paint, pet food and many more. In these applications, it is rarely necessary to track pigs along the entire length of the pipeline. Instead, the systems monitor whether a pig has passed one or more predetermined key points.
Please note, although some of the principles are similar, the pig tracking technology used to track and locate pigs in large diameter pipes, such as those used in the oil and gas production and supply industries, is different. If you’re looking for information about large bore utility pig tracking systems, you can find more information on the Pigging Products and Services Association website, for example in this article.
Types of Pig Tracking
The most basic form of pig tracking is visual. This is simply where an operator physically looks to see the pig location. However, as most liquid processing applications are closed systems, use solid pipework and use pigs which travel at high speeds, solely relying on visual pig tracking is neither practical, reliable nor safe. Instead, the most effective solution is to use non-intrusive pig detection. This gives a physical indication that the pig has passed a particular point, as well as an output signal suitable for PLC and control systems.
HPS pigs do not contain solid magnets. This is because solid magnets present a significant contamination and safety risk (similarly, HPS pigs do not have any fins, caps or assembled components which can break off). Instead, HPS pigs have a magnetised, flexible silicone core. This enables them to be accurately and reliably detected and tracked using HPS non-intrusive pig detectors.
HPS pig detectors mount externally on the pipe being pigged. To track the pig, when a pig passes the detector, the detector picks up the pigs magnetic field. To provide a visual indication to the operator, an LED on the detector lights as the pig travels past. More importantly, the detector provides a signal specially designed for highly accurate and reliable tracking and automation using PLC and control software.
HPS pigs reside off line until they’re needed. They’re usually housed in launch and receive stations specially designed to enhance the CIP process. This is ideal because, as well as improving the CIP process, it also ensures the pigs do not contact the product until absolutely necessary.
The HPS pig detectors are nearly always sited at launch stations and receive stations. In addition (depending on the system), pig detectors may also be mounted at other key locations such as drop off, tank or bottling points. However, because HPS pigs do not get stuck, it’s possible to accurately programme pigging automation systems using the logic that if a pig is not at one location, it must be at another. This reduces the number of pig detectors required while still enabling highly reliable and effective pig tracking.
Find Out More
Although often associated just with oil and gas, pipeline pigging and product recovery solutions help a wide range of other industries and sectors improve product yields, reduce waste, increase profits, become more efficient and enhance their environmental credentials.
For more information about pig tracking, pig detection, product recovery, pigging system automation, or to find out how hygienic and sanitary pipeline pigging products and systems can help your liquid processing operation, then please get in touch.