Pump Types
POSITIVE DISPLACEMENT PUMPS
Zeilfelder pumps work by using two rotating elements, unmeshing at the suction side of the pump, to create a vacuum that fills the spaces created between the elements and the suction casing. These spaces then transport the fluid along the outer casing to the discharge side where the gears re-mesh and discharge the fluid. Positive displacement pumps are designed to handle large changes in pressure, viscosity and flow rate and are often used for highly viscous liquids with large percentages of solids.
EXTERNAL GEAR PUMPS
are self-priming, non-pulsating and reversible pumps that work best on clean, lubricating fluids with a viscosity thicker than water. Two gear teeth, one idler and one driver, mesh together to transfer the liquid. Because of the balanced construction and bearings on both sides of the shafts, the pumps are capable of non-pulsating flow and high pressures.
INTERNAL GEAR PUMPS
are self-priming, non-pulsating and reversible pumps that work best on clean, lubricating fluids with a viscosity thicker than water. Two gear teeth, one idler and one driver, mesh together around a crescent divider to transfer the liquid. Because of the simple one shaft construction, Internal Gear Pumps are less expensive than comparable pumps and are very easy to maintain.
ROTARY LOBE PUMPS
are self-priming, dry-run capable and reversible pumps designed for highly viscous liquids containing solid particles. Two non-contacting rotary lobes work together to transfer the liquid, while the shafts are driven by timing gears outside the process liquid.
Because of the very large internal cavities, rotary lobe pumps are able to handle extremely viscous liquids and large abrasive particles.
MULTI-WING PUMPS
are a combination of gear and rotary lobe pumps designed for highly viscous liquids containing small solid particles. Two noncontacting lobes, consisting of multiple wings, work together to transfer the liquid, while the shafts are driven by timing gears outside the process liquid.
Because of the large number of lobes, multi-wing pumps are self-priming, dry-run capable and reversible pumps capable of handling extremely viscous liquids and small abrasive particles.
