The reasons for corrosion of materials beneath the insulation layer and their relationship to the concept of pipeline insulation

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The reasons for the corrosion of materials beneath the insulation layer are related to the concept of pipeline insulation. 1. The relationship between heat and cold: It must be noted that heat and cold are relative terms. If the temperature of a pipe reaches 200 degrees Celsius while the surrounding temperature is 100 degrees Celsius. Although we consider 100°C to be hot, it is cold according to the entire thermal system. The basic law of heat transfer is that temperature always moves from high to low. Hot air contains more moisture than cold air. When hot air comes into contact with the insulated pipe, it cools down rapidly, thereby reducing the heat transfer rate. Water is released; in other words, it condenses. 2. Heat transfer and air flow have no relative relationship. Heat energy can flow through metals, insulating layers, air, etc. For example, a beach with rolling waves. You see that it’s not actual water splashes hitting the shore (in fact, the small boat and debris floating on the water cannot create waves; they can only move up and down as the waves reach the bottom). Heat waves in thermal energy can also be transmitted through materials, and the decrease in temperature is due to a reduction in the heat transfer rate (the speed of the heat waves). Therefore, the air temperature is directly related to the fact that the temperature of the heat source (the air surrounding the steam or cold pipes in the factory) is higher than the temperature of the air near the insulation. No matter how small the distance between the insulation layer and the base is, a temperature difference always exists. 3. Corrosion of the insulation layer: Moisture remains trapped inside this layer, so it’s easy to guess what will happen. When a layer of moisture remains trapped on the surface of the metal, corrosion occurs.