Municipal water pipelines face several issues throughout their lifespan. Compounding issues can impact the water taste and odor, affect capacity negatively, increase pumping costs, and cause biofilm complications. Several types of pipeline cleaning methods exist to address these issues, clear debris and improve the system performance of water and force mains.

Perhaps two of the most well-known cleaning technologies are hydraulic pigging with foam pigs and Ice Pigging™. Each method has its own strengths and challenges that will influence which is best for a pipeline cleaning project.

Traditional Pigging Pros and Cons

Traditional hydraulic pigging initially uses a “prover pig” equipped with a location device to check for obstruction. Then a series of specialized cleaning pigs navigate the pipe to remove sediment and scale propelled by system pressure. 

Advantages

Beneficial for long miles and piping of all diameters

Using various sized pigs, traditional hydraulic pigging can clean a broad range of pipeline diameters up to 96 inches. Pigging can (generally), also clean longer segments without stopping when compared to Ice Pigging™, although Ice Pigging™ is certainly capable of pigging 2-3 miles of smaller pipe diameters.

Pigs rarely get stuck

Although a large concern of using foam pigs is that they may get lodged somewhere along the line, this rarely happens. In its over 100 years of combined experience in pipeline pigging, American Pipeline Solutions has only had a problem with a lodged pig when severe line obstructions are present. The identification and location (pigs can be tracked) of these obstructions and subsequent removal are essential to returning flows to original/near original rates. An ice pig will never become permanently stuck, because it will just melt.

Navigates short radius elbows, tees, and most types of valves

When materials and pig types are used correctly, pigs have no issue traveling through short radius elbows, Ts, and several valve types.

Restores pipelines to near original conditions or close to it

Hydraulic pigging will return a pipe to almost original conditions.

Smart Pigs detect potential integrity issues in the pipeline before they arise

For cast iron, ductile, and steel mains, SmartFoam Tools are both cost-effective and successful in evaluating pipeline integrity. This technology can identify cracks, wall anomalies, and internal corrosion in a less disruptive manner than conventional in-line inspections.

Disadvantages

Requires involved set-up processes

Traditional pigging requires the installation of a launcher and receiver through which to run pigs. This installation process can add time to an overall pigging operation, especially when excavations are involved.

Consumes more water

Compared to Ice Pigging™, traditional pigging techniques can use up to 50% more water for a typical operation. Uni-directional flushing will likely use 5 times more water.

Ice Pigging™ Pros and Cons

Ice Pigging™ is a newer technology that uses an ice slurry instead of solid pigs to clean common pipeline issues, such as sediment, deposits, and biofilms. Ice is 1,000 times more effective than flushing with water alone.

Advantages

Flexible to the varied topography of pipes

Due to its almost liquid form, (a liquid that behaves as a solid) Ice Pigging™ is malleable to a range of changing pipe sizes and obstacles such as pipe bends, and butterfly valves pose no problem to an ice pig

Exceptional low risk will never get stuck permanently

As its name suggests, Ice Pigging™ depends mainly on ice as its main material, meaning that the “pig” will melt away even if the slurry gets blocked. 

Faster than traditional pigging for underground pipes

Ice Pigging™ requires less of a physical set-up than traditional pigging, as it doesn’t need a launcher and catcher installed at both ends of the pipeline. In most cases, the ice is introduced via existing fittings, such as fire hydrants, air release values, or even manual air bleeds and washouts. As long as the opening is two inches or greater, the ice can be injected into the pipe in twenty minutes or less.

Disadvantages

Not as aggressive as a traditional hard pig

The ice pig is not as aggressive as a hard pig and is unlikely to remove hard tuberculation or calcified fats, oils and grease (FOG).

Not very successful for large diameter piping

Ice Pigging™ is best suited for diameters ranging from 1.5” 3 inches to 24 inches. For larger diameters, traditional pigging is usually a better option assuming there are not too many bends or obstacles that a hard pig will not pass.

Not likely to discover obstructions

Because the ice slurry is less likely to get stuck and cannot be tracked, there is less chance of detecting obstructions that may hint at a larger issue. An unknown closed valve on the system or full blockage will quickly be discovered in the ice insertion process, however.

Learn more about the best solution to solve your pipeline flow issues

American Pipeline Solutions is North America’s oldest continuous pigging company with over 100 years of combined experience. We have pigged and restored over two million feet of pipeline to near original conditions.

Contact American Pipeline Solutions to learn more about our institutional expertise and to request a quote.