---
title: "Scaling"
description: "Scaling is the deposition of inorganic mineral salts (calcium carbonate, calcium sulphate, silica, magnesium silicate) on heat-transfer surfaces — typically the liquid side of an exchanger or boiler tube. Scaling is the dominant fouling mechanism in cooling-water systems, multi-effect evaporators, water-side boiler tubes and process heat exchangers."
canonical_url: "https://sylio.co/glossary/scaling"
last_updated: "2026-06-28T02:29:32.250Z"
---

**Scaling** is the deposition of inorganic mineral salts (calcium carbonate, calcium sulphate, silica, magnesium silicate) on heat-transfer surfaces — typically the liquid side of an exchanger or boiler tube. Scaling is the dominant fouling mechanism in cooling-water systems, [multi-effect evaporators](/glossary/multi-effect-evaporator), water-side boiler tubes and process heat exchangers.

## Distinguishing scaling from gas-side fouling

<table>
<thead>
  <tr>
    <th>
      Attribute
    </th>
    
    <th>
      Scaling
    </th>
    
    <th>
      Gas-side <a href="/glossary/fouling">
        fouling
      </a>
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Side of the tube
    </td>
    
    <td>
      Liquid side
    </td>
    
    <td>
      Gas side
    </td>
  </tr>
  
  <tr>
    <td>
      Mechanism
    </td>
    
    <td>
      Inverse-solubility chemistry
    </td>
    
    <td>
      Particulate adhesion
    </td>
  </tr>
  
  <tr>
    <td>
      Cleaning
    </td>
    
    <td>
      Chemical, hydroblast
    </td>
    
    <td>
      Mechanical, acoustic, steam
    </td>
  </tr>
  
  <tr>
    <td>
      Sonic-horn applicability
    </td>
    
    <td>
      None
    </td>
    
    <td>
      Where dry, friable
    </td>
  </tr>
</tbody>
</table>

[Sonic horns](/glossary/sonic-horn) address gas-side fouling, not water-side scaling. Liquid-side scale removal is the province of chemical cleaning campaigns, hydroblasting and other specialised techniques.

## Related terms

- [Fouling](/glossary/fouling)
- [Multi-effect evaporator](/glossary/multi-effect-evaporator)
- [Cold-end corrosion / dew-point corrosion](/glossary/cold-end-corrosion-dew-point-corrosion)