Central boiler rust inhibitors are chemical compounds designed to prevent corrosion and rust formation in the boiler system. These inhibitors are essential for maintaining the efficiency and longevity of the boiler. Here are some commonly used types:

1. Sodium Nitrite: A widely used corrosion inhibitor that forms a protective oxide layer on metal surfaces.

2. Sodium Molybdate: Acts as a corrosion inhibitor by forming a protective film on metal surfaces, especially effective in preventing pitting corrosion.

3. Phosphates: Help in forming a protective film on metal surfaces and also contribute to scale prevention. For example: ATMP , HEDP...

4. Silicates: Create a protective layer on metal surfaces, particularly effective in high-temperature environments.

5. Amines: Neutralizing amines (e.g., morpholine, cyclohexylamine) are used to control pH and prevent corrosion in the steam-condensate system.

6. Organic Corrosion Inhibitors: Such as tannins and polyamines, which form protective films on metal surfaces.

7. Polyphosphates: Help in preventing scale and corrosion by sequestering metal ions and forming protective films.

8. Benzotriazole and Tolyltriazole: Specifically used for protecting copper and copper alloys.

9. Chelating Agents: Such as EDTA (ethylenediaminetetraacetic acid) and NTA (nitrilotriacetic acid), which bind to metal ions and prevent them from participating in corrosion processes.

10. Oxygen Scavengers: Compounds like sodium sulfite, hydrazine, and ascorbic acid that remove dissolved oxygen, a primary cause of corrosion in boiler systems.

11. Filming Amines: Create a protective film on metal surfaces, offering long-lasting protection against corrosion.

Using the right combination of these inhibitors, depending on the specific boiler system and its operating conditions, can effectively prevent rust and corrosion, ensuring efficient and long-term operation.