Removing ½ inch thick hard-rock limescale from a power station’s cooling tower pipework

Three weeks after installing AquaVantage the station’s expected ½’’ hard-rock limescale was reduced to a thin film of sludge that was easily wiped away.

About the power station

This coal-fired power station has 12 parabolic cooling towers and six transformers. Each transformer supplies some two per cent of power to the National Grid.

Cooling water is abstracted from a major nearby river. It is then filtered, dosed with sodium hypochlorite bactericide and pumped as coolant water. There is some recirculation, but the majority of the coolant left after evaporation is returned to the river. For practical purposes, we viewed this system as a straight to waste ‘once through’ system.

The challenge

The abstracted water had an average calcium hardness of 400ppm with a pH of 8.0. This solution already had the potential to scale, while the injection of the sodium hypochlorite bactericide caused the pH to rise significantly.

The dilution water in the 8″ pipe, down stream of the 2″ side-stream, had a pH measuring never less than 10.0. This pH gave rise to supersaturation and calcium was precipitating as calcium carbonate that formed a hard-rock fouling (calcite) in the pipes. The station undertook work to remove fouling by acid washing every two days and water jetting every 2-3 months.

Our solution

Our large-scale digital water treatment unit was fitted to an 8″ dilution side-stream pipe upstream of one of three points where sodium hypochlorite was injected. In brief, the electro-magnetic waveform induced by our unit converted calcium bicarbonate in the river water to calcium carbonate crystals, which then flowed suspended in the coolant and returned to the river.

Three weeks after application – and with no acid washing having taken place during this time – the station’s pipes were examined. Instead of the expected ½” hard-rock limescale, only a thin film of sludge was seen. This sludge was easily removed by wiping.

The right solution

Whether a larger industrial pipe or a small domestic network, our AquaVantage units scale to fit. The external pipe size of the installation point sets the electrical characteristics for the unit you will require.

Domestic unit

Our smallest unit for household use, on incoming main and boiler pipework

Mid-range unit

For mid-range sized pipes such as commercial buildings, hotels, swimming pool supply lines


Our largest standard units for major industrial pipes well over a meter in diameter

To discuss your requirements… CONTACT US TODAY

Meet others who have solved scale issues

Our success when working at a brine plant to help solve carbonate and sulphate fouling in its system was said to be a world first.
Read the case study about our work at a brine plant ›



  • We’re a technology company using a unique electromagnetic waveform and our own tech to digitally treat water and solve the toughest of scale problems in pipes of all sizes. From domestic pipework to large-scale industrial pipes, we’re confident you’ll typically achieve payback within 3-12 months. If not, we’ll work with you to make it work.

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