Selection Method Of Water Pump

Dec 09, 2024

1. Choose a water pump that meets the head requirements

The so-called head refers to the required head, not the lifting height, and it is particularly important to clarify this when choosing a water pump. The head of the water pump is approximately 1.15-1.20 times the lifting height. If the vertical height from a water source to the water usage point is 20 meters, the required lift is approximately 23-24 meters.

When selecting a water pump, it is best to ensure that the head on the pump nameplate is close to the required head, with a general deviation of no more than 20%. In this case, the pump has the highest efficiency and is more energy-efficient, making it more economical to use. If the lift on the nameplate is much lower than the required lift, the water pump often cannot meet the user's needs, and even if it can pump water, the amount of water is pitifully small. But conversely, when a high head water pump is used for low head, there will be excessive flow, causing the motor to overload. If it runs for a long time, the temperature of the motor will rise, and the insulation layer of the winding will gradually age, even burning out the motor.

2. Choose a water pump with appropriate flow rate

The flow rate of the water pump, that is, the water output, should generally not be selected too large, otherwise it will increase the cost of purchasing the water pump. It should be selected according to needs, such as the self-priming water pump used by users in their homes, and the flow rate should be selected as small as possible; Users can choose submersible pumps with higher flow rates for irrigation.

3. Key to selecting agricultural water pumps

1) Choose water pumps according to local conditions. There are three types of commonly used agricultural water pumps, namely centrifugal pumps, axial flow pumps, and mixed flow pumps. Centrifugal pumps have a high head but a small water output, making them suitable for mountainous areas and well irrigation areas; Axial flow pump has a large water output, but the head is not too high, suitable for use in plain areas; The output and head of mixed flow pumps are between centrifugal pumps and axial flow pumps, and are suitable for use in plain and hilly areas. Users need to make purchases based on local conditions, water sources, and lifting heights.

2) Choose a water pump that exceeds the standard appropriately. After determining the type of water pump, its economic performance should be considered, especially the selection of the pump's head, flow rate, and supporting power. It must be noted that the head indicated on the water pump label (total head) is different from the actual head at the time of use (actual head), as there will be some resistance loss when the water flows through the water supply pipe and near the pipeline. So, the actual head is generally 10% -20% lower than the total head, and the water output is correspondingly reduced. Therefore, in actual use, it can only be estimated based on 80% to 90% of the head and flow rate indicated on the label. The selection of the matching power for the water pump can be based on the power indicated on the label. In order to make the water pump start quickly and use safely, the power of the power machine can also be slightly higher than the required power of the water pump, generally about 10% higher; If there is already power, when selecting a water pump, you can choose a water pump that matches the power of the power machine.

3) Strict procedures must be followed when purchasing water pumps. When making a purchase, it is necessary to verify the product certificate.