Argal sump pumps are centrifugal pumps with vertical axle, column and casing submerged, electric motor long coupled to pump by mean of its own stool or short coupled directly to the pump; are always actuated with an electric motor placed well above the liquid to be pumped. No metallic part is ever in contact with the fluid pumped; designed to pump aggressive chemical liquids are characterised, even in the smaller details, by constructive solutions conceived to maximise service life and functionality.