Single-stage vertical centrifugal pumps, suitable for transfer, recycling and distributing corrosive liquids. The AS-series pumps are recommended for installation in cisterns, tanks or wells with variable head. The manufacturing technologies, the materials employed and the hydraulic design adopted permit the vertical AS pumps to satisfy plant specifications for chemical products (including those with solids). Hydraulics are optimized using open, closed and recessed impellers, and impellers with different speeds of rotation in accordance with the constraints imposed by the plants, the nature of the liquids or the working processes.