Submersible pumps are ideal for use with ring wells. The pumps are installed in special casing pipes. The pumps have an integrated cooling jacket. The role of monoblock submersible pumps is to draw water from the bottom upward; some models also have a grinder function, as shown in the video: https://www.youtube.com/watch?v=25uq0YBIw78&t=28s
What is a casing pipe used for?
When choosing the right submersible pump to match the well diameter, we should not limit ourselves to this one criterion. It is equally important to consider the width of the tank, as excessive width can negatively affect the service life of the pump motor. We will demonstrate this using the example of the IBO 3.5SDM 3-15 pump, with a diameter of 90 mm, and:
A - a deep well with an internal diameter of 100 mm,
B - a ring well with a diameter of 1 m.
In the first case, where the difference between the pump and the well wall is 5 mm, the amount of water surrounding the pump is also small, which ensures efficient water exchange, continuously replenished from the aquifer surrounding the well. Efficient water flow helps cool the motor. However, if the distance between the pump and the well wall is almost 0.5 m, water is drawn in at the height of the suction inlet, and the motor is not cooled. The motor heats up during operation, thereby increasing the water temperature, which shortens its service life.
General pump selection principle
The general principle for selecting a pump based on the well diameter states that the difference between the pump diameter and the well’s internal diameter should be no less than 4 mm and no greater than 100 mm. This is worth considering when purchasing a pump, as submersible pumps with diameters ranging from 50 mm to 160 mm are most commonly available on the market. We present how the professional IBO KRAKEN 1800 grinder pump for dirty wastewater operates in the video: https://www.youtube.com/watch?v=srPLsaIKsqM&t=27s
Other hazards in pump operation
The presence of sand in a well is one of the most common causes of pump damage. Therefore, we recommend browsing the range of IBO submersible pumps from the Polish manufacturer. Pumps from the IBO 2.5STM, 3STM, 3ti, 3SDM, 3.5SDM, and 4SDM series feature a design based on so-called floating impellers. This design means that the individual pump stages, including the impellers, are mounted on the pump shaft. This arrangement allows axial clearance to be maintained, enabling the entire hydraulic section inside the tube to move several centimeters up and down. Even if sand gets inside, the preserved clearance prevents damage to the structure. The recommended pump models were the first on the Polish and European markets to earn the nickname “SAND-RESISTANT”.
Another model incorporating this solution is the Italian-made IBO ITALY FP4 series pumps. They also feature the “DRY RUN PRO” solution, which protects the pump against operation in a so-called dry cycle, meaning without water — for example, when the water table drops as a result of drought.
