Pipeline Pigging: From Scraper Pigs to ABB Robots

Pipeline pigging means sending a device called a pig through a pipeline, pushed along by the oil, gas or water flowing behind it, to clean the line or to inspect the steel from inside. Bangkok saw it in the news this autumn: after a leak 6.6 centimetres long was found on the Rama III oil pipeline in September 2026, the operator was to run an intelligent pig along the whole 32-kilometre line, with Thailand's Department of Energy Business overseeing the work. This post follows pigging from scraper pigs to the first intelligent pigs of the 1960s and today's robotic crawlers, and looks at where ABB robots could fit.

A smart pig about to be installed in a 36-inch high-pressure gas line in Los Angeles, 2012. Photo: Lemonnn / Wikimedia Commons (CC BY-SA 4.0)

From straw bales to the first intelligent pigs

The first cleaning pigs were made from whatever worked. Some were straw bales wrapped in barbed wire, others were made of leather, and the squealing noise they made inside the pipe gave pigs their name. The pig goes into a pig launcher, and the pressure of the product flow pushes it along the pipe until it reaches the receiving trap. Besides cleaning, pigs separate different products in a multiproduct pipeline and clear slugs of liquid out of pipelines that carry gas and liquid together.

A scraper pig shown at the Trans-Alaska Pipeline System visitors center. Photo: Leijurv / Wikimedia Commons (CC BY-SA 4.0)

Pigs started to measure as well as scrape in the 1960s. In 1961 Shell Development ran the first intelligent pig, and in 1964 Tuboscope ran the first commercial instrument, which used magnetic flux leakage to inspect the bottom part of the pipe. Magnetic flux leakage, or MFL, uses a powerful magnet to magnetise the steel, and the magnetic field leaks out of the wall where there is corrosion or missing metal. Intelligent pigs today use technologies such as MFL and ultrasound to inspect the pipe wall from the inside, and a single run can cover the full length of a long transmission line.

An intelligent pig on display at the Museum of Science and Industry in Manchester, with its electronics on show. Photo: Symac / Wikimedia Commons (CC BY-SA 4.0)

In-line inspection grew into a global business. Hermann Rosen founded the ROSEN Group as a one-person start-up 45 years ago. It now has more than 4,000 employees and serves 18 of the world's 20 largest pipeline operators, and in September 2026 he received the IPCE Lifetime Achievement Honor in Calgary. Many lines still cannot take a pig, though. Changes in diameter, butterfly valves and tight bends make a pipeline unpiggable, and operators then need other ways to see inside.

Inserting a pig into a natural gas pipeline in northern British Columbia, Canada. Photo: Dexcel / Wikimedia Commons (public domain)

Intelligent pigs and crawlers at work in 2026

In Bangkok the pig comes after several other checks. The operator, a Bangchak Group company, stopped fuel transport on 8 September, tested the coating and pressurised the line to its normal 28 barg for an hour without finding a leak. An ultrasonic scan later found the damaged spot under a 1.8-metre pipe sleeve: 6.6 centimetres long and 7 millimetres deep. After the repair, the full-length intelligent pigging run is meant to measure wall thickness and find other weak points. In Poland, Gaz-System has just finished an intelligent pig run on its 250-kilometre Gdańsk to Gustorzyn gas pipeline.

A pig launcher on a pipeline near Albachten, Münster, Germany, 2015. Photo: Dietmar Rabich / Wikimedia Commons (CC BY-SA 4.0)

Two launches in September 2026 show where the tools are going. NDT Global launched QUADRA, which combines ultra-high-resolution axial MFL with circumferential MFL and other data in one run, to find corrosion, seam anomalies and hard spots. "The future is not about individual inspection technologies operating independently," said Paul Cooper, NDT Global's president. Expro launched Velonix, which clamps a sonar meter onto the outside of the pipe to measure the pig's speed and automatically adjusts the flow to keep it in the right range, with no operator correcting it during the run.

Large foam pigs used to scrub the inside of an aqueduct, pushed through by the water pressure behind them. Photo: Bindersbee / Wikimedia Commons (public domain)

For lines a pig cannot pass, operators can send a robot. In 2025 Pacific Gas and Electric and Intero Integrity Services inspected 6,400 feet of 10-inch gas transmission pipe installed in 1966. Intero's tetherless, self-propelled Pipe Explorer entered through temporary hot-tap fittings, so gas kept flowing, and collected axial and circumferential MFL, laser deformation and internal video across 146 pipe spools. It reported 30 longitudinal indications, four of them over the reporting threshold. Those four showed up clearly in the circumferential MFL data but not in the axial data. The paper notes that a free-swimming pig can be impractical where access is limited, flow is low or there is no permanent launcher and receiver.

A robotic pipe crawler seen inside a large pipe, with its control monitors beside it. Photo: U.S. Department of Energy / Wikimedia Commons (public domain)

Where pigs, crawlers and ABB robots go next

ABB has built an inspection robot that travels inside equipment before. In 2018 it introduced TXplore, a tetherless submersible robot that moves through an oil-filled transformer with propellers and buoyancy control and films the bushings, leads, tap changer and core. ABB reported that an inspection needed two people on site and less than one day, against three or more days for a human inspection. Our transformer inspection robot post tells that story. Pipeline crawlers do a similar job inside a pipe: they move through the asset and bring back images and sensor data.

A technician lowers ABB's TXplore robot through a manhole into an oil-filled transformer. Photo: ABB

ABB does not make pigs or pipeline crawlers, so any role for its robots is a possibility. One place is the workshop where inspection tools are put together and serviced, since assembly and screwdriving are two jobs ABB lists for its GoFa cobot. GoFa comes in 5, 10 and 12 kg versions, can work next to technicians without fencing, and is set up with graphical apps on the FlexPendant, the approach behind our graphical programming lessons. A cell like that could be planned first in RobotStudio.

An ABB GoFa CRB 15000 cobot being guided by hand at an assembly table. Photo: ABB

The open problems come from old pipe and from trust in the data. Hermann Rosen describes an industry facing aging and new pipeline assets and increasing regulatory requirements, and on 4 October Forbes reported that a $390 million pipeline rule leans on inspection data vouched for mostly by industry. Robots that work inside an asset have to earn trust as well. Before TXplore went into service, ABB tested prototypes for leaks for more than 96 hours at more than twice the expected field pressure and checked their navigation in seven oil-filled tanks. Pipeline crawlers face the same kind of proof, while tools like Velonix take manual adjustment out of the run and QUADRA collects more data from each pass.

TXplore navigating inside an oil-filled transformer, its lights on. Photo: ABB

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