A Screw Pump is a type of Positive Displacement pump that uses two or more screws that intermesh to pressurize fluids and move them in a system. The screws take in fluid then push it out from the other side while increasing its pressure.
Types of the Screw Pumps
There are three main types of screw pumps
1.Single Screw Pump – A single screw rotates in a cylindrical cavity, thereby moving the material along the screw’s spindle.
2.Two/Double screw pump (twin screw pump) – These pumps operates by using two intermeshing screws as described above. The pump is often equipped with timing gears located outside the pumping chamber that are lubricated with oil in order to ensure the two screws are rotating properly. Due to the design, the screws are not required to be in direct contact with each other which helps extend the life of the pump.
3.Three screw pump (triple screw pump) – They utilize one driving screw intermeshed with the other two screws to create pressure and move fluid. The screws do come into contact with each other, which often limits the pump to handling only clean liquids.
Screw Pump Applications
Due to their ability to provide high flow rates even in viscous liquids screw pumps are ideal for fuel transfer, elevators, and other similar industrial applications. Single screw pumps are used for simple water movement such as for sewage inlet pumps, storm water pumping, drainage pumping, and to move industrial waste water.
Screw Pump Application Ranges
- Flow Rate Ranges – 50 to 15,000 gallons per minute, 189 to 56,781 liters per minute
- Total Head (Pressure) Ranges – 50 to 4,500 psi, 3 to 310 bar
- Horse Power Ranges – 5 to 5,000