Learn - Sep. 18, 2025
Generally, a self-priming pump is typically a centrifugal pump with a design of a built-in water tank, which is supposed to be filled up with water only before the first time of starting the pump, and this process of filling water is called priming. On the other hand, the other type of centrifugal pumps must be filled up with water every time you start the pump. Obviously, the self-priming pumps are particularly designed to avoid the troubles of priming for each start of pump. The built-in water tank design allows the self-priming pumps to evacuate air from pump body and pipe lines, thus it enables the pump to generate a vacuum and start to intake the water without further external assistance. As a result, those pumps become the ideal choice for intaking water from a lower position. In this article, we will list the features, types, advantages and disadvantages of self priming centrifugal pumps to help you have a clear understanding of them before purchasing.
The centrifugal self-priming pumps have the outstanding feature of the built-in water tank, which requires priming before the first starting of the pump, this particular feature frees those pumps from the troubles of repeating priming jobs.
Most self-priming pumps in the market also include a check valve or flapper valve inside of the pump suction, which prevent backflow to the lower position, secure prime retention during shutdown, and reduce the need for manual repriming.
Many self-priming pumps feature an internal recirculation channel that returns a small part of the discharged water back into the pump casing. This backflow helps in moving air out of pump casing during the priming process, and therefore it enables faster and more reliable starts.
Due to their strong suction capability, the self-priming pumps are suitable for various challenging applications including building drainage, wastewater transportation, agricultural irrigation, flood control, and industrial processes involving gas entrainment or variable suction conditions.
Due to the compact design of pump structure and optimized hydraulic models, the self-priming pumps can work efficiently while requiring less maintenance compared to other type of pumps, in this way, they are able to lower the operating costs and enhance the overall reliability.
A Centrifugal self-priming pump works by creating a vacuum in the pump, then due to the function of vacuum, it intakes the water into the pump casing and discharge the water through the pump outlet nozzle. Below is the working process of those pumps:
During the initial startup, the built-in water tank and the pump casing must be filled with fluid. This fluid can be clean water or the pumping fluid, it is important to prime enough fluid into the water tank and pump casing, otherwise the starting time of the self-priming pumps can be longer than normal.
When the self-priming pump is activated, the rotation of the impeller generates centrifugal force, which propels the liquid outward. Simultaneously, the liquid within the impeller vanes drives air toward the discharge or outlet section of the pump casing. The accumulated air is subsequently expelled through a dedicated vent or an automatic air release valve.
The vacuum in the pump and suction pipe can be formed as the water in the pump casing is pushed out by the rotating impeller, and the formed vacuum enables the pump to intake the water from a pool or any lower position places.
The vacuum formed in the pump casing draws water from the suction pipe into the pump. This incoming water fills the space previously occupied by the expelled air, thus completing the priming process and enabling normal pumping operation.
Once the water enters the pump casing, the incoming water combines with the retained water and is propelled by the impeller toward the discharge outlet, enabling continuous flow.
Most of the self-priming pumps have the design of non-return valves like check valves or flapper valves in the suction nozzle to stop the water from returning back into the pool or tank after the pump is shut down. These valves are the key design to hold the priming and avoid the repeating priming for the next start-up of pump.
The self-priming pumps are able to work smoothly and efficiently after the priming process is finished. They can evacuate small amounts of air or particles that may enter the pump casing during operation, so they may maintain effective pumping performance. It is important to know that the designs and operational characteristics may vary between different manufacturers and applications. Some models may include additional designs such as recirculation systems, sealing systems, water tanks, or unique impeller designs to improve self-priming performance. Anyway, the proper installation, regular maintenance, and consistent monitoring are essential factors to maintain the smooth and efficient operation of self-priming pumps.
Based on the different requirements from the clients, there are various types of self-priming pumps available in the market. We'll list some of the most widely used types as follow:
4.1 Centrifugal Type Self-Priming Pumps are the most popular and widely used type of self-priming pumps, which rely on a rotating centrifugal impeller to form the vacuum that intake the water from a lower position. Thus, the centrifugal models are widely used and accepted in many industries including irrigation, flood control, waste water transfer, chemical plant...
4.2 Centrifugal Sewage Self-Priming Pumps are the type of self-priming pump which are particularly designed and built to transfer the sewage water contains particles, debris, solids and even cloth. Those pumps are mainly working in flood control sites, municipal projects, construction sites, mines...
4.3 Diaphragm Self-Priming Pumps rely on a flexible diaphragm to convey the water. They are capable to manage the viscous liquids, liquid with solids or aggressive chemicals, making them well-suited for applications such as chemical processing, chemical transfer, and wastewater treatment.
4.4 Rotary Vane Self-Priming Pumps generate a vacuum in the way of rotating vanes to intake the liquid. They are the ideal choices are pumping light liquids like fuels and light oils, and are commonly employed in automotive and fuel transfer applications.
4.5 Liquid Ring Vacuum Type Self-Priming Pumps utilize an eccentrically mounted rotating radial-vaned impeller to create a vacuum, and with the function of the vacuum, the fluid can be drawn from a lower position. The vacuum type self-priming pumps are the ideal equipment for sewer cleaning, sewage water transfer and air or gas transfer.
4.6 Peripheral Type Self-Priming Pumps, also referred to as regenerative or side-channel pumps, utilize an impeller with radial vanes to circulate fluid along a peripheral channel within the pump casing. This mechanism forms a continuous flow and enables reliable self-priming performance. Such pumps are particularly suited for applications requiring small flow rates and high discharge pressures.
4.7 Vertical Self-Priming Pumps have the feature of compact and space saving design due to the vertical orientation of pump arrangement, this allows them for a quick installation and easier maintenance. Those vertical pumps are ideal for the applications which have restrictions of the space, however, lower efficiency and relatively higher power consumption is the disadvantage of those models.
4.8 Piston Type Self-Priming Pumps have the key part of reciprocating pistons which are used to draw the fluid and push it to the discharge nozzle. These pumps are commonly employed in applications demanding high pressure, such as pressure washers and firefighting equipment.
Different type of self-priming pumps have distinct advantages, meanwhile each of them have different restrictions. The selection of an appropriate pump depends on various factors, including the type of fluid to be handled, the fluid temperature, the solid content condition, required flow rate, operating pressure, and specific application needs. Proper selection, installation, and maintenance are essential to ensure efficient and reliable pump performance of different type of self-priming pumps.
The self-priming pumps is a type of multi-functional pumping device which is widely used in many scenarios and applications including water transfer, chemical solution handling, flood control, waste water handling...We are going to list some of the most widely used applications as follow:
5.1 Wastewater Treatment: Due to their excellent ability of solids and particles handling, the centrifugal type self-priming pumps have been widely acknowledged as the ideal and efficient pumping devices for transferring sewage for municipal projects, wastewater treatment project, chemical solution transportation...
5.2 Agricultural Applications: Due to the feature of self-priming and capability of intaking water from lower places like wells, ponds or any other sources of water, the self-priming centrifugal pumps are quite suitable for the agricultural purposes of farm irrigation.
5.3 Marine Applications: Due to the advantage of customization of wetted parts material, the self-priming pumps can be made from duplex stainless steel or even titanium alloy, making them ideal to remove seawater from bilge.
5.4 Flood Control & Water Evacuation: Due to the design of large capacity and moderate discharge pressure, those pumps can evacuate the flood in a relatively short period of time, so they are quite popular for flood control applications as well as emergency water evacuation.
5.5 Chemical Mediums Handling: Thanks to the various options of wetted parts material, the self-priming chemical centrifugal pumps have excellent ability to manage the many chemical fluids from lower to high temperatures. Also, due to their ability of holding the priming, they are ideal for intaking chemical fluids from tanks or raw material ponds in chemical plants.
5.6 Mining & Underground Applications: Due to the excellent ability of maintaining the priming and dewatering, those pumps are widely employed in the various mining or underground infrastructures for the rapid dewatering purpose.
5.7. Firefighting Applications: Self priming pumps have good ability to intake water from water sources like ponds, lakes and rivers, this feature making them the most ideal choice for firefighting purpose. Furthermore, due to their capability of maintaining the priming, they can work for emergency fire smothering.
5.8 Municipal Applications: Because of the features of self-priming and ability to draw the water from lower places, those pumps are also widely used in municipal projects where it requires to intake water from reservoirs or rivers to the waterworks.
The above applications prove the versatility of self-priming pumps, representing their capacity to take care of the wide range of fluids, manage solid-containing mediums, and deliver reliable performance even under demanding conditions. However, to ensure optimal operation among the diverse applications, the proper pump model selection, correct installation, and in time maintenance are critical.
It is believed that after going through this article, you would have a clear and comprehensive understanding of self-priming pumps, which are essential pumping devices for many demanding applications including water supply, chemical fluids transfer, firefighting, flood control, etc. With decades of experience in designing and manufacturing these pumps, we are committed to delivering high-performance and tailored pumping solutions to satisfy the needs from customers. Our self-priming pumps are designed with advanced priming ability and robust construction to ensure rapid priming, smooth operation and minimal maintenance; thus, our self-priming pumps are able to work efficiently and safely. Trust in our expertise, we'd like help you to select the ideal pumps that offer longevity, energy saving, and consistent performance under the tough conditions. Contact us now to get a quick quote or suggestions regarding those self-priming pumps.
Contact us now: sales@zgpumpvalve.com or wa.me(Whatsapp: +8613738006567)
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