Tobee Replacement AHLSTAR APP/T 51-300 end-suction single-stage centrifugal process pumps with cartridge mechanical seal are used for Clean and lightly contaminated liquids, Viscous liquids, Fibrous slurries, Large solids containing liquids and Gas containing liquids and self-priming applications. APP High performance process pumps for demanding applications AHLSTAR APP end-suction single-stage centrifugal process pumps are used for demanding industrial applications to ensure process reliability, high efficiency and low operating costs.