High performance vertical bobbin wound filters are manufactured using reinforced polyester with glass fibre, which is completely anti-corrosive, with high mechanical, chemical and thermal resistance. One of its main characteristics is the height of its filtering layer. Dirt is driven through the sand bed and trapped in minute spaces between the particles of sand. Initially, a clean bed will remove larger particles and then as the sand bed starts to load up, it will remove finer particles. The higher this is, the better its performance.