Industrial bobbin wound filters with diameters from 1050 mm to 3000 mm, with the corresponding flange connections for different filtration velocities. Replaces the Atenas model. New top cover system with quick closing system 400 x 500 mm opening. The air relief valve is fitted into the cover in order to help eliminate air from the filter. 1½” collector arms injected in ABS at the necessary lengths for each of the filters and without joints. Lenghts from 90 mm to 525 mm. A reduced head loss is achieved thanks to the greater diameter of the arms. The 90 mm diam collector tubing is injected in PVC. Water purge and air relief are faster due to a 1" connection. The distance between the top sand layer and the difusor head (“freeboard”) has been increased to ensure greates water distribution during filtration and to prevent sand entering into the laterals during the backwashing. In filters with diameters of 2350 mm, 2500 mm and 3000 mm, the top cover is Ø 400 mm, sealed with bolts for high resistance. Available for pressures up to 2.5 and 4 bars.