The flow of the water pump, that is, the water output, should not be too large in general, otherwise it will increase the cost of purchasing the water pump. It shall be selected as required. For example, the self-priming water pump used by the user’s family, the flow shall be smaller as far as possible; If users use submersible pumps for irrigation, they can appropriately select those with larger flow.
1) We should choose and buy water pumps according to local conditions. There are three types of commonly used agricultural water pumps, namely centrifugal pump, axial flow pump and mixed flow pump. Centrifugal pump has high lift, but small water output, which is suitable for mountainous areas and well irrigation areas; The axial flow pump has large water output, but the head is not too high, so it is suitable for plain areas; The water output and head of mixed flow pump are between centrifugal pump and axial flow pump, which is suitable for plain and hilly areas. Users should choose and buy according to the local conditions, water source and water lifting height.
2) The water pump shall be properly selected. After determining the type of water pump, its economic performance should be considered, especially the selection of pump head, flow and supporting power. It must be noted that the head (total head) indicated on the water pump label is different from the outlet head (actual head) in use, because there will be a certain resistance loss when the water flows near the water delivery pipe and pipeline. Therefore, the actual head is generally 10% – 20% lower than the total head, and the water output is reduced accordingly. Therefore, in actual use, it can only be estimated according to 80% ~ 90% of the lift and flow indicated on the sign. The selection of the supporting power of the water pump can be based on the power indicated on the sign. In order to make the water pump start quickly and use safely, the power of the power machine can also be slightly greater than the power required by the water pump, which is generally about 10% higher; If there is power, when purchasing the water pump, you can choose the matching water pump according to the power of the power machine.
3) Strict procedures should be followed to purchase water pumps. When purchasing, we should verify the “three certificates”, namely agricultural machinery promotion license, production license and product inspection certificate. Only when the three certificates are complete can we avoid purchasing obsolete products and inferior products.
