What is Limescale and how to remove and prevent it.

Limescale: The efficiency killer. 

Limescale (aka scale, lime) deposits don’t just impact your small home appliances, showers, and bathtub. The damaging effects of limescale deposits in industrial equipment cost industrial and commercial buildings billions of dollars a year due to increased downtime and additional maintenance, which results in reduced efficiencies and ultimately drives up operating expenses.

As limescale builds up in heat exchangers, evaporative coolers, boilers, chillers, and other water-fed equipment, it forces equipment to work harder to get the job done. Over time, limescale coatings also cause corrosion that eats away pipes and equipment, making conditions ripe for leaks and other damages.

Building operations, plant, and facilities managers should descale equipment regularly, safely, and effectively to prevent system damage and keep facility costs in check.

What is limescale, and what is it made of?

The minerals that cause limescale are always present in your water supply. Limescale, also known as calcium carbonate (CaC03), is a hard, chalky white deposit that gets left behind on surfaces when hard water evaporates. However, this condition afflicts more than tap water—even soft water can form calcium carbonate deposits when highly concentrated.

Limescale deposits build up in facility plumbing systems, heat exchangers, evaporative coolers, boilers, and chillers and are difficult to remove. When allowed to build up, the chalky deposits reduce water flow, destroy equipment efficiency, and can cause equipment to consume more energy.

What causes limescale buildup?

Limescale deposits happen as hard water contacts solid surfaces. Mineral scale deposits occur from heat transfer or pressure changes.

Hard water is water with high mineral content. It forms when water percolates through deposits of limestone, chalk, or gypsum, minerals comprised mainly of calcium and magnesium carbonates, soluble calcium bicarbonates, and sulfates.

The U.S. Geological Survey (USGS) estimates that around 85% of the U.S. has moderate to very hard water. Humans can drink hard water, but it can damage plumbing systems and mechanical equipment.

The dissolved Co2 and HC03 ions in water form a compound of calcium and magnesium carbonate ions. This chalky residue builds over time, leaving limescale stains and buildup behind. The more layers that build, the more it can damage equipment function, longevity, and appearance.

Water temperature matters too. Limescale loves hot water. The hotter the water, the quicker limescale builds up. However, chilled water can experience scale buildup as well.

Is limescale harmful to you or your systems?

Limescale buildup can cause considerable damage within water-cooled or heated equipment.

It can make plumbing fixtures appear dirty, especially in restrooms where it builds up in toilets, sinks, and showerheads, giving bathrooms used by building occupants and the public a dingy and cloudy appearance.

Limescale builds layers in pipework, where the scale reduces water flow area and increases pipe wall friction. This can result in buildings requiring a larger, energy-hungry pump to maintain throughput volumes. But powerful pumps represent a temporary solution. Eventually, the pipework will need cleaning. In the meantime, the building may experience leaks, increased operational noise, and boosted energy consumption.

One-quarter inch of limescale buildup on a heat exchange surface reduces heat transfer and can increase energy use by up to 40%. Here, facility and plant managers may need to install expensive, heavy-duty heat exchangers to compensate. Scaled boiler tubes also may overheat and fail. Cooling towers can collapse from heavy-scale deposits. Worse, limescale build can potentially shorten equipment lifespans and lead to unplanned shutdowns, costing a significant amount of money.

Also, limescale buildup can corrode steel surfaces, leading to fluid leaks and equipment failure, which is costly and dangerous. Fouled safety valves or emergency process sensors may fail to operate in an emergency. Overheated boilers can explode. Bacteria can thrive in limescale buildup, creating water quality issues that can present a health hazard to building occupants.

What does limescale look like?

Limescale and other mineral deposits are not always evident to the naked eye. Often, they occur in closed systems within a building. However, facility and plant managers can watch for the following clues, which show a need to remove limescale.

  • Higher unexplained energy bills
  • Increased planned and unplanned downtime
  • Heat exchangers that perform below design
  • Corrosion problems across the facility
  • Signs of deposits within the system

Another way to identify limescale removal needs is to evaluate water quality and hardness. USGS defines water containing 61 to 120 mg/L of calcium carbonate as moderately hard, enough for limescale to flourish.

How to remove and prevent limescale buildup.

Now we know what scale is, how do we remove thick scale? The phrase “the best offense is a good defense” applies to more than just sports. It applies to limescale as well. Limescale, once formed, is not easily cleaned up or wiped away. It can be exceedingly difficult to remove.

Preventing and controlling limescale buildup in mechanical and plumbing equipment saves money, reduces maintenance, and prevents premature equipment failure. It’s easier to prevent limescale buildup than remove limescale once it starts. The best way to get ahead of limescale is to chart equipment performance daily, or at least weekly, to schedule and perform maintenance before limescale becomes a problem.

But standard cleaners won’t do the job, and toxic chemicals can be harsh and irritating to the technicians who use them. Salt-free products and water softeners can also do the trick, but they are also hard on equipment, have high maintenance, and are very expensive.

Goodway ScaleBreak® liquid descaler is the limescale defense facility and plant managers need. It dissolves mineral deposits quickly, safely, and sustainably.

The high-performance biodegradable industrial descaler rapidly dissolves calcium, lime, rust, and other deposits from water-cooled or heated equipment, including chiller tubes, flywheels, boiler tubes, brazed plate exchangers, and more. The scale dissolves into liquid suspension that technicians can flush from the system.

ScaleBreak® liquid descaler is fortified with low foaming and penetrating agents and comes in various sizes to meet the needs of any size commercial or industrial facility.

Because equipment alloys can differ, we make ScaleBreak® safe to use on steel, iron, brass, copper, plastic, and rubber alloys. The blend cleans alloys thoroughly without damaging the base metals.

ScaleBreak® dissolves 2 pounds of scale per gallon of product. However, the overall volume and scale severity determine how many applications systems may require. We simplify these calculations with Goodway descaler calculators, which can help you calculate how much ScaleBreak® you would need and potential cost savings.

Next Steps

Limescale prevention and removal are necessary at every industrial and commercial facility. Click here to learn more about Goodway Industrial Descaling Systems and Solutions. Need help in determining which descaler is suitable for your needs? We’ve outlined which descaler will best meet your needs here. Don’t get caught off guard without a limescale prevention and/or removal plan.

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