In the chemical, petroleum, food and other industrial fields, valves are one of the key control equipment. However, in the process of conveying corrosive media, valves are susceptible to corrosion damage, affecting their function and life. Therefore, taking effective anti-corrosion methods is an important measure to protect valves and ensure the safety of industrial production. This article will introduce several common valve anti-corrosion methods.
Principle
The principle of valve anti-corrosion mainly includes two aspects: chemical anti-corrosion and electrochemical anti-corrosion. Chemical anti-corrosion mainly forms a corrosion-resistant coating on the surface of the valve material to prevent the corrosive medium from directly contacting the valve material. Electrochemical anti-corrosion is to make the valve the cathode of the corrosion cell by sacrificing the anode or applying an external current, thereby preventing corrosion from occurring
Method

1. Surface treatment: Clean, polish, degrease and other treatments on the valve surface to remove surface dirt and impurities, improve surface flatness and roughness, and facilitate the adhesion of subsequent coatings.

2. Coating protection: Apply a layer of corrosion-resistant coating, such as epoxy resin, polyurethane, etc., on the surface of the valve to form a protective film to block the penetration of corrosive media.

3. Electroplating: Electroplating a layer of corrosion-resistant metal on the surface of the valve, such as chrome plating, nickel plating, etc., to enhance the corrosion resistance of the valve.

4. Cathodic protection: By applying an external current, the valve becomes the cathode of the corrosion cell to prevent corrosion. This method is mainly suitable for valves used underground or underwater.

Technology

When selecting a valve anti-corrosion method, the following aspects need to be considered: 1. The nature of the corrosive medium: Different corrosive media require different anti-corrosion methods.

2. Use environment: The use environment has a great influence on the selection of anti-corrosion methods, such as temperature, humidity, pressure, etc.

3. Valve type: Different types of valves require different anti-corrosion methods, such as ball valves, gate valves, stop valves, etc.

4. Maintenance and care: Different anti-corrosion methods require different maintenance and care measures.

Case

The acid pipeline of a chemical plant uses stainless steel valves, but because the medium being transported is highly corrosive, the sealing surface of the valve is often corroded. In order to solve this problem, the following measures were taken:

1. Clean, polish, degrease and other treatments were carried out on the valve surface to improve the surface flatness and roughness.

2. Special acid-resistant stainless steel materials were used as the materials for the valve body and valve trim to improve the corrosion resistance of the valve.

3. A layer of corrosion-resistant coating, such as epoxy resin, was applied to the valve sealing surface to form a protective film to block the penetration of corrosive media.

4. The maintenance and care of the valve was strengthened, and the sealing materials were regularly checked and replaced to keep the valve in good working condition. By taking the above measures, the corrosion problem of stainless steel valves in the acid pipeline was effectively solved, ensuring production safety and production efficiency.