Silo tanks for milk intake depend on storage capacity. It is size ranges from 5.000 to 50.000 liters and wet surfaces are made of stainless steel. They are often placed outdoors to save on building costs. In these cases, the tanks are insulated. They are double insulated with minimum 70 mm mineral wool insulation. The outer shell can be stainless steel, but for economic reasons, it is usually made of mild steel and coated with anti-corrosion paint.