Phosphate Dosing

Why phosphate dosing required in boiler ? (Central BOE-2021)

Phosphate dosing is required in boilers for two main reasons: to prevent scaling and corrosion, and to maintain proper pH levels.

**Scale prevention**

Scale is a hard deposit that can form on the inside of boiler tubes and other components. It is caused by the precipitation of minerals, such as calcium carbonate and magnesium sulfate, from the boiler water. Scale can reduce heat transfer efficiency, increase corrosion, and eventually cause boiler failure.

Phosphates prevent scale formation by reacting with the minerals in the boiler water to form a complex that is more soluble and less likely to precipitate. This complex is then removed from the boiler through blowdown.

**Corrosion control**

Corrosion is the deterioration of a metal surface due to a chemical reaction. It can be caused by factors such as exposure to oxygen, acids, or bases. Corrosion can weaken boiler components and lead to leaks or failures.

Phosphates help to control corrosion by raising the pH of the boiler water. A higher pH level makes the water less acidic and less likely to corrode metal surfaces.

**Maintaining proper pH levels**

The pH of boiler water is a measure of how acidic or alkaline it is. A pH of 7 is neutral, a pH of less than 7 is acidic, and a pH of more than 7 is alkaline.

The ideal pH range for boiler water is between 8.5 and 9.5. This range helps to prevent both scale formation and corrosion.

Phosphates can be used to raise the pH of boiler water if it is too low. They can also be used to maintain the pH at the ideal level.

**Overall, phosphate dosing is an important part of boiler water treatment. It helps to prevent scale formation and corrosion, and to maintain proper pH levels.**