How Does Ice Pigging™ Work? Pipe Cleaning Method
Since its development in 2001 by Professor Joe Quarini at the University of Bristol, Ice Pigging™ has transformed how utilities and industries clean pipelines. Unlike traditional methods, which often require heavy equipment, chambers, or chemicals, Ice Pigging™ combines the cleaning strength of a solid pig with the flexibility of a liquid. The result is a powerful, cost-effective, and environmentally friendly pipe cleaning solution that delivers up to 1,000 times more shear force on internal pipe walls than conventional flushing.
Today, municipalities, water companies, and industrial facilities around the world rely on Ice Pigging™ to restore water quality, extend asset life, and improve pumping efficiency — all with minimal downtime and disruption.
But what exactly is Ice Pigging™, and how does the process work in practice? Below, you’ll find a step-by-step guide to the Ice Pigging™ process, along with answers to common questions and insights into why this innovative method is becoming the preferred choice for pipeline cleaning.
What Is Ice Pigging™?
Ice Pigging™ is a pipeline cleaning process that uses a semi-solid ice slurry. This slurry, made of countless small ice crystals suspended in water, forms what is known as the ice pig™.
Unlike traditional mechanical pigs, which are rigid objects, the ice pig behaves like a liquid during insertion but acts like a solid plug once inside the pipe. As it moves, it applies extremely high shear stress to the internal pipe walls, dislodging sediment, biofilm, iron, manganese, and other deposits.
Because the slurry is flexible, it can adapt to bends, diameter changes, and valves without risk of damage or blockage. And if the ice pig ever stops moving, it simply melts, leaving the pipe clear.
Pipeline Experts: Inspection, Cleaning, Coating & More
Certified solutions for inspection, pre-commissioning, cleaning, internal coating, ice pigging™, mapping, and turnkey pipeline projects—maximizing safety and reliability at every stage.
A Step-By-Step Guide To Ice Pigging™: How It Works
Below is a breakdown of how Ice Pigging™ is carried out in real-world applications. Each step is carefully managed to ensure safety, efficiency, and water quality compliance.
Step One: Isolating the Pipeline
Technicians begin by isolating the main pipeline section. This involves closing upstream and downstream valves, as well as any connecting intersections. Once isolated, the ice slurry — delivered via a specialized tanker — is pumped into the system using 2.5” fire hoses connected to hydrant posts.
Step Two: Controlled Injection
As the slurry enters the pipeline, operators carefully monitor both flow and pressure. This ensures the cleaning process is forceful enough to dislodge fouling but safe enough to avoid pipe damage. Once the section is filled, the upstream valve is opened to push the ice pig through the main using system pressure.
Step Three: Cleaning in Action
The ice pig then travels through the pipeline, scraping away accumulated material such as sediment, biofilm, manganese, and iron deposits. These contaminants are carried within the slurry itself and directed to an exit point, where they are discharged into tankers or a sanitary sewer for proper disposal.
Step Four: Flushing and Return to Service
After the ice pig has exited the system, the pipeline is flushed with clean water until both ice remnants and debris are removed. This ensures the pipe meets strict water quality standards. Because the process requires no harsh chemicals, there is no need for disinfection, and the pipeline can be safely returned to service almost immediately.
What Are the Common Reasons for Ice Pigging™?
Now that we have discussed the step-by-step procedure of Ice Pigging™, it's time to look at the common reasons why municipalities choose Ice Pigging™. Have a look below to learn more.
Ice Pigging™ uses a fraction of the water that flushing and conventional pigging does, making it more environmentally friendly.
Ice Pigging™ can be used for decommissioning cleaning when pipework needs to be cleaned of all residue sediment before it is dismantled.
Ice Pigging™ can be completed when a pipe needs to be cleaned because its use will be changed or if a new product will be used in conjunction with the original piping.
Ice Pigging™ is used to aid with asset management by extending the life of a pipeline to ensure capital spent on pipes and pumps is kept to a minimum.
Ice Pigging™ is perfect for removing accumulations of sediment, biofilm, and foreign objects that are affecting water quality. For example, to improve odor, taste, and lower turbidity levels as well as improve chlorine residuals.
Ice Pigging™ can be employed when a major piping overhaul is planned, and a deep clean of a pipe network is required.
Ice Pigging™ is ideal for improving a sewer force main pumping efficiency by reducing back pressure and increasing flows.
Why Do Municipalities and Industries Use Ice Pigging™?
Ice Pigging™ is chosen over other pipe cleaning methods for several compelling reasons:
Water efficiency – requires only a fraction of the water compared to conventional flushing.
Environmental benefits – avoids harsh cleaning chemicals and reduces wastewater volume.
Asset management – extends pipeline life, helping utilities and industries defer costly replacements.
Improved water quality – enhances taste, odor, and chlorine residuals while lowering turbidity levels.
Operational flexibility – can be performed quickly with minimal system downtime.
Hydraulic performance – reduces back pressure, increases flow, and improves pump efficiency.
Change of use cleaning – prepares pipes for new products or operational changes.
Pre-commissioning or de-commissioning – ensures pipelines are free of debris before use or dismantling.
Beyond municipal water networks, Ice Pigging™ is also widely applied in industries where clean, efficient pipe systems are critical:
Food & Beverage – to eliminate product residues and biofilms safely.
Pharmaceutical & Healthcare – for sterile, contamination-free pipelines.
Chemical & Manufacturing – for process line preparation and maintenance.
District Heating & Cooling – to improve energy efficiency and reduce fouling.
How Is Ice Pigging™ Different from Traditional Pigging?
Despite what many might believe, Ice Pigging™ is different from traditional pigging. Unlike traditional pigging, Ice Pigging™ carries much less risk because it is inserted and removed via existing pipeline fittings. There is an increased chance for risk and disruptions to a pipeline with conventional and foam pigging.
For example, there are installation and launching chambers required, and if the pig or swab gets stuck, a team will have to spend time to locate it then reverse the flow to move it back to the launcher or in the worst case dig it up. In contrast, if the ice pig were to get stuck in a pipeline, the ice would simply melt without causing any problems to a pipeline's infrastructure.
Ice Pigging™ is a far less disruptive pipe cleaning method because a pipeline outage will only take a few hours compared to a few days with other pipe cleaning methods. This means water is restored faster with Ice Pigging™. Interestingly, Ice Pigging™ doesn’t require a lengthy chlorination process, so a pipeline can be returned to service immediately after being cleaned.
Pipeline Experts: Inspection, Cleaning, Coating & More
Certified solutions for inspection, pre-commissioning, cleaning, internal coating, ice pigging™, mapping, and turnkey pipeline projects—maximizing safety and reliability at every stage.
What Are the Limitations of Ice Pigging™?
Although highly effective, Ice Pigging™ does have some limitations:
Pipe size restrictions – most effective in pipelines up to 24 inches in diameter.
Sediment hardness – not ideal for removing very hard, calcified deposits.
Distance limits – typically effective for cleaning up to 2.5 miles of 6-inch pipe in a day.
For these reasons, professional evaluation is essential to determine whether Ice Pigging™ is the right solution for a specific project.
Get In Touch With American Pipeline Solutions for Your Ice Pigging™ Needs
Ice Pigging™ is a sophisticated process that requires specialized equipment and expertise. At American Pipeline Solutions, we are the only company in the United States currently offering Ice Pigging™ services. Our team has extensive experience performing this method for municipalities and industries, helping clients improve water quality, extend asset life, and reduce operational costs.
If you’re considering Ice Pigging™ for your pipelines, we’d be happy to discuss your needs. Contact us directly at paul@americapipe.com, or complete our project questionnaire and include supporting maps so we can assess your system in detail.
FAQs:
What is Ice Pigging™ in simple terms?
Ice Pigging™ is a pipe cleaning method that uses a semi-solid ice slurry instead of a rigid foam or mechanical pig. The slurry behaves like a liquid during injection and like a solid plug while moving through the pipe. As it travels, it scrapes and carries away sediment, biofilm, iron, manganese, and other deposits with very high shear force.
How does Ice Pigging™ actually clean a pipeline?
During Ice Pigging™, a controlled volume of ice slurry is injected into an isolated section of pipe and then pushed through using system pressure. The ice pig conforms to the pipe’s shape, applying intense shear stress to the internal walls. Dislodged material is trapped in the slurry and discharged at a designated exit point before the pipeline is flushed and returned to service.
What types of deposits can Ice Pigging™ remove?
Ice Pigging™ is highly effective at removing soft and semi-hard deposits such as sediment, biofilm, iron and manganese buildup, and organic material that affects water quality. It is also useful for clearing foreign objects and residues left from normal operation or product changes. Very hard, calcified deposits may require additional or alternative cleaning methods.
Where is Ice Pigging™ commonly used?
Ice Pigging™ is widely used by municipalities and water utilities to restore water quality, reduce turbidity, and improve chlorine residuals. It is also applied in industrial networks where clean, reliable flow is critical, including food and beverage, pharmaceutical, chemical, and district heating and cooling systems. In many cases, it supports asset management and pre-commissioning or de-commissioning activities.
How is Ice Pigging™ different from traditional pigging?
Traditional pigging relies on rigid foam or mechanical pigs that require launching and receiving chambers and can get stuck if conditions are not ideal. Ice Pigging™ uses an ice slurry that can be injected and removed through existing fittings, navigate bends and diameter changes more easily, and simply melt if it stops. This significantly reduces the risk of blockages, excavation, and prolonged outages.
What are the main advantages of Ice Pigging™ for utilities and industries?
Ice Pigging™ typically uses much less water than conventional flushing, does not require harsh cleaning chemicals, and produces less wastewater. It can often be completed in hours rather than days, minimizing downtime and disruption. At the same time, it improves water quality, boosts pump efficiency, reduces back pressure, and helps extend pipeline life as part of an overall asset management strategy.
Are there size or distance limits for Ice Pigging™?
Yes. Ice Pigging™ is most effective in small to medium diameters, typically up to around 24 inches, and over defined distances per cleaning run. For example, a common reference point is cleaning up to a few miles of 6-inch main in a day. Larger diameters or very long sections may require alternative methods or a combination of techniques.
Is Ice Pigging™ environmentally friendly?
Ice Pigging™ is considered an environmentally friendly pipe cleaning method because the ice slurry is made from water and a small amount of salt, with no harsh chemicals. It uses significantly less water than traditional flushing and generates a lower volume of wastewater. Once the process is complete, the remaining ice simply melts, leaving no additional residues in the system.
How quickly can a pipeline be returned to service after Ice Pigging™?
In most cases, a pipeline can be returned to service soon after Ice Pigging™. Once the ice pig has exited the system, the line is flushed with clean water until ice remnants and debris are removed and water quality standards are met. Because no aggressive chemicals are used, there is usually no need for lengthy disinfection steps, which shortens downtime.
When should I choose Ice Pigging™ over other cleaning methods?
Ice Pigging™ is an excellent choice when you need high cleaning performance with minimal disruption, especially in water networks and sensitive or complex piping systems. It is ideal when water conservation, reduced chemical use, faster return to service, and lower blockage risk are priorities. A professional evaluation can determine whether Ice Pigging™ or a combined cleaning approach is best for a particular pipeline.
