The Damaging Effects of Scale on a Facility’s Infrastructure

What is Scale?

Scale is the concentration of minerals (often calcium and magnesium) that form when water is heated and the minerals precipitate from the water and collect on the surfaces of pipes, plumbing fixtures and equipment that uses water. Water with a high mineral content is considered hard at 7 grains per gallon (gpg) and does not have to be truly hot to form scale. Even slight changes in temperature can cause scale buildup on plumbing infrastructure.

Negative Effects of Scale

Facilities that operate industrial equipment such as boilers, chillers, condenser systems, HVAC systems and cooling towers in hard water areas should be concerned about the accumulation of scale. Scale buildup on critical building systems causes machinery to work harder than necessary, reduces efficiency and can be extremely costly in increased energy use. Fuel is typically a facility’s biggest operating expense. If hard water causes scale build-up on a boiler’s tubes, the boiler becomes less efficient and requires more fuel to generate the same heat transfer. Even what seems like nominal thickness, one one-hundredth to one-tenth of an inch, can have damaging effects. A layer of scale just 1/8-inch thick can cause as much as 20 to 25 percent loss in efficiency. The company uses more fuel, and their number one expense increases even more.
In addition to increased energy costs, scale can lead to overheating, ruptures, increased maintenance and repairs, costly downtime, shortened equipment lifespan and the eventual failure of equipment.

Mitigating Scale

Water conditioning and treatment are essential to substantially mitigating scale. The first line of defense is ion exchange water softeners. Softeners remove the hardness minerals of calcium and magnesium from water which reduces scale buildup. Softeners help to ensure the quality of makeup water for boilers and chillers. Another piece of the water treatment program can be chemical treatments that inhibit scale as well as corrosion. A water treatment program can include multiple methods working in conjunction with regular maintenance and inspections. An appropriate plan will lower a facility’s operating cost as well as prolong equipment life.

Treating Scale Once It’s Deposited

Industrial chemicals such as phosphates, polymers and chelates are used to remove scale once it is deposited on equipment. The need to clean scale from plumbing systems and equipment is greatly reduced if not eliminated by starting with a pre-treatment program. The best way to treat scale is to prevent its formation in the first place.

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