Multi screw pumps belong to the group of self-priming, valve-less rotating positive displacement pumps. Due to their design they are specially suitable for lubricating media. Although they are compact in design they can reach high flow rates and high pressure. Some designs are even suitable for non-lubricating or solid loaden fluids.
The delivery principle is based on a drive spindle transferring torque through a thin hydrodynamic film to the rotating intermeshing one or two driven spindles.
Designs that are suitable for non-lubricating media as well, need a timing gear to synchronize the spindles.
The rotation of the screw creates chambers what will moved continously from the suction to the discharge side and create a negative suction pressure and the media will be drawn in.
The matching design of housing and screws hydraulically balances against high radial and axial loads to guarantee a long service ife of the pump.
Various housing designs make the pumps suitable for all installation situations.
The most important fields of applications comprise the transfer of lubricants e.g. in the energy production or transport industry. But also in various process industries and the oil and gas sector and here especially for tank storage multi screw pumps are often used.