How a Centrifugal Water Pump Works
- By Jackson Carter
- Jun 22, 2018
A centrifugal water pump is one of the most common types of water pumps available, but how does it work? What are the different parts and what do they do?
How a centrifugal water pump works:
The first thing you need to know is the purpose of a centrifugal water pump. A centrifugal pump is very versatile, and can be used for agriculture, industrial, and many other applications. Their main job is to transport liquid from one place to another.
Some centrifugal water pumps have solids handling capabilities, which means they can move liquids that have solids in them (up to a certain extent), as well as chemicals, making these pumps very popular. Centrifugal pumps are classified as kinetic pumps, and the way centrifugal pumps move a substance is through kinetic energy (motion). This is done through a part called the impeller, which is a large, usually metal rotor, that spins very quickly, much like the impeller on a motor boat.
The basic parts of a centrifugal water pump:
Pump Body/Casing
The pump body, or casing, is the external case of a water pump. It’s what houses the impeller, the volute, and all the other internal parts. The pump body is most commonly made of cast iron, due to more economical manufacturing costs, but can also be made of stainless steel, bronze, plastic or other materials. Its main purpose is to house all the internal working parts of the pump. It’s like the case of a computer, in that it keeps all the parts in, and helps protect them.
Volute
A water pump volute is a kind of curved funnel leading to the discharge port that widens out the farther it goes. It is a casing around the impeller that the liquid comes into contact with as it enters the pump. As the water enters the volute, the volute helps decrease the speed/flow of the water or liquid, while increasing the pressure, which helps to balance the pressure on the impeller shaft. The volute can be made of either cast iron, steel, plastic, or bronze.
Some centrifugal pumps incorporate the pump body and volute as one piece, thus the pump body/casing also functions as the volute.
Impeller
The impeller can be made of a variety of materials. The most common are cast iron, bronze, brass, stainless steel and plastic. Bronze and stainless steel are mostly used for ocean water, while temperature resistant steel can be used for hot or cold water. Plastic is most commonly used for chemicals and other caustic and corrosive liquids.
The liquid comes in through the suction port (inlet), which then pushes it towards the pump impeller. As the impeller spins very quickly, it forces the liquid out of the discharge port (outlet). It works much like a vacuum cleaner, in that the energy from the impeller sucks the liquid in, spins it around, and pushes it back out the discharge port at a high rate of speed.
Power
A centrifugal pump can be powered from a variety of power sources. Most commonly, they are powered by an electric motor, a gas or diesel-powered engine, or a hydraulic motor, all which power the pump by driving the shaft that spins the impeller.
Pump Shaft
Another important part of a centrifugal pump is the pump shaft, which is what the impeller is mounted to. The pump shaft connects to the motor or engine, which then powers the impeller and makes it spin. An important part of the shaft is the shaft sleeve, often made of cast iron, stainless steel or bronze which helps to better fit the impeller onto the shaft, as well as protecting the shaft from damage and wear and tear.
AMT Stainless Steel Centrifugal Pump
