Internal corrosion protection of valves mainly focuses on the contact surface between the inner cavity of the valve and the medium to prevent the medium from corroding the inside of the valve. The main anti-corrosion measures include:

Material selection based on medium characteristics: Select appropriate valve materials according to the characteristics of the medium the valve contacts, such as corrosiveness, temperature, pressure, etc. For example, for highly corrosive media, corrosion-resistant materials such as stainless steel and alloy steel can be selected.

Coating protection: Apply anti-corrosion paint to the inner cavity of the valve to form a protective film to isolate the direct contact between the medium and the inner cavity of the valve. The choice of anti-corrosion paint should be determined according to the characteristics of the medium and the use environment.

Optimized design: Reasonable valve structure design and processing technology can reduce the occurrence of corrosion. For example, avoiding stress concentration, reducing design details such as welding joints, can reduce the risk of corrosion.
 

External corrosion protection of valves mainly focuses on the corrosion protection of the valve housing and connecting parts to prevent the external environment from corroding the valve. The main anti-corrosion measures include:

Surface cleaning and treatment:

Mechanical rust removal: Use sandpaper, wire brushes and other tools to clean the valve surface to remove rust and dirt.

Sandblasting: Use compressed air to spray abrasives at high speed onto the valve surface to remove surface dirt and oxide layer, and improve surface roughness and adhesion.

Spraying anti-corrosion paint: Spray a layer of anti-corrosion paint on the valve surface to form a protective film to isolate the valve body from oxygen and moisture in the air. The choice of anti-corrosion paint should be determined according to the material, use environment and anti-corrosion requirements of the valve.

Spraying: Spray plastic powder evenly on the metal surface of the valve through a spray gun, and then bake it at high temperature to melt, level and solidify the plastic powder to form a dense coating.

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

Installation of protective sleeve: Install plastic sleeve, rubber sleeve and other protective sleeves on the outside of the valve to isolate the valve body from direct contact with the external environment.

Wrapping anti-corrosion tape: Wrap a layer of anti-corrosion tape, such as polyethylene anti-corrosion tape, glass ribbon, etc., on the surface of the valve to form a protective layer.

Anodic protection: By applying an anodic current to the protected metal, a passivation film is formed on its surface, thereby preventing the occurrence of corrosion reactions.

Cathode protection: By applying an external current, the valve becomes the cathode of the corrosion battery to avoid corrosion. This method is particularly suitable for valves used underground or underwater.

Regular maintenance: Regularly inspect the valve to check whether it has corrosion, wear and other problems, and deal with them in time. At the same time, regularly clean the dirt and corrosion products on the surface of the valve to keep its surface clean and smooth.

Environmental control: Where possible, slow down the corrosion process by controlling the temperature, humidity, oxygen concentration and other factors in the environment where the valve is located. For example, open workshops or ventilation and cooling measures are used to reduce ambient temperature and humidity.