The PU-series is a submersible vortex pump designed for raw sewage, wastewater, and liquid carrying solid matters. It is made of resin and 304 stainless steel and excellent in corrosion-resistance. The vortex mechanism provides practically unchokable operation in sewage pumping. Liquid paraffin is used for the lubricating oil, which widens the application of the pump to decorative waterfalls, fishponds, aquaculture, etc.