In several applications that require liquid to be pumped, the pump must be kept above the level of liquid. This lets air into the line, which can often create issues like overheating and pump failure. To avoid this from happening, a self-priming pump is used to empty out the air before moving the fluids.
A self-priming pump is like other centrifugal pumps but is built with an outer casing that contains the fluid being pumped. The rotation of the impeller in this casing creates an area with low pressure at the impeller’s eye. This causes the fluid, along with the air, to get pushed up into the pump through the line of suction. Through its motion, the self-priming pump causes the air to separate from the fluid and get released from the casing. When all of the air has escaped, the pump allows the fluid to flow. Thus, a self-priming pump essentially removes any air pockets from the fluid to ensure smooth delivery by the pump.
The main difference between a self-priming pump and a regular centrifugal pump is that there is no need to physically prime the former type, as its extra in-built mechanism is designed to do just that.
A self-priming pump can be used for anything that requires a standard centrifugal pump. This can include pumping water, sewage waste or other industrial applications.
It is important to choose the right kind of pump for the task at hand, as well as the correct sized pump that matches the flow and head. Then, a net positive suction head (NPSH) calculation must be conducted to make sure there is adequate atmospheric pressure to sustain the required flow. Lastly, the speed of the pump must be high enough to be able to prime itself. The size of its line of suction too must be selected carefully.
Advantages of a self-priming pump
Because self-priming pumps are installed above the fluid source, the infrastructure needed to set them up is relatively less. They are easy to access due to their ground-level location. Maintenance and repair too, are simpler to conduct on a self-priming pump than on a regular centrifugal pump.
Self-priming pumps can handle a variety of liquids as well as slurries and suspended solids. They are also ideal for frequent pumping operations, as the steps involving pump priming at the start are eliminated. As well, they use less power and time to run than other centrifugal pumps. Self-priming pumps are also safer to operate, as hoists or cranes are not required for their use.
Limitations of a self-priming pump
Self-priming pumps have a limited suction lift. There are limitations in the NPSH and fluid temperature and can cause a loss of friction in the line of suction.
For more information on industrial pumps, motors, and other equipment, contact VEMC on +91 98199 07445. We would be glad to provide customized support for your requirements. We are well-established industrial water pumps dealers in Mumbai who deliver end-to-end project management services to our clients. VEMC is ISO 9001:2015 certified and a pioneer in the field of electromechanical engineering products, allied equipment, and services.