Notice
To ensure its normal service life, enameled equipment is not suitable for chemical processes involving the following media or materials:
- Hydrofluoric acid of any concentration and temperature, as well as media or materials containing fluoride ions.
- Phosphoric acid media or materials with a concentration greater than 30% and a temperature exceeding 180°C.
- Alkaline media or materials with a pH value greater than 12 and a temperature higher than 80°C.
- Reaction processes involving alternating acid and alkaline materials.
The corrosion resistance of enameled equipment is based on the formation of a silicon-oxygen protective film on the glass-lined surface upon contact with the medium, which prevents corrosion of the substrate. When the glass-lined layer comes into contact with strong alkaline solutions, a silicon-oxygen protective film cannot form on its surface, allowing the alkaline solution to continuously erode deep into the glass layer. The degree of erosion becomes more severe with higher concentrations and temperatures of the strong base. Boiling strong alkaline solutions exhibit the greatest erosive capacity.
An important consideration within the applicable scope of enameled equipment is its temperature adaptability. It is evident that steel and glass layers have different coefficients of thermal expansion. When the equipment undergoes rapid temperature changes, excessive stress can cause porcelain bursting and damage the equipment. To prevent such damage, attention should also be paid to the temperature differentials within the applicable range of the medium, specifically a cold shock tolerance of 110°C and a hot shock tolerance of 120°C. Therefore, heating or cooling of the equipment should be carried out slowly.
