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.
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 choose based on the local conditions, water source, and lifting height.
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 "three certificates", namely the agricultural machinery promotion license, production license, and product inspection certificate. Only when all three certificates are present can the purchase of obsolete and inferior products be avoided.
Quantity selection
1. For normally operating pumps, only one is usually used because a large pump is equivalent to two small pumps working in parallel (referring to the same head and flow rate), and the efficiency of the large pump is higher than that of the small pump. Therefore, from an energy-saving perspective, it is better to choose a large pump instead of two small pumps. However, in the following situations, parallel cooperation of two pumps can be considered: the flow rate is large, and one pump cannot reach this flow rate.
2. For large pumps that require a 50% backup rate, two smaller pumps can be switched to work, with two backup pumps (a total of four pumps)
3. For some large pumps, pumps with a flow rate requirement of 70% can be operated in parallel without the need for a backup pump. When one pump is under maintenance, the other pump still undertakes 70% of the production transportation.
4. For pumps that require 24-hour continuous operation, three pumps should be standby, one in operation, one as backup, and one for maintenance.
Distinguish between genuine and fake
Firstly, the packaging of original water pumps or supporting manufacturers' products is generally standardized, with clear and formal handwriting, detailed product names, specifications, registered trademarks, factory names, addresses, and telephone numbers; Counterfeit accessories usually have rough packaging and unclear factory address and name printing.
Secondly, qualified water pumps have a smooth surface and good workmanship. The more important the spare parts, the higher the processing accuracy, and the stricter the packaging rust and corrosion prevention. If rust spots, rubber cracking, loss of elasticity, or obvious machining patterns are found on the surface of the shaft neck when purchasing, it should not be an original accessory from the factory.
Thirdly, the appearance of low-quality water pumps can sometimes be good. However, due to poor manufacturing processes, it is easy to be damaged. When purchasing, simply observing the hidden parts such as edges and corners of the accessories can reveal the quality of the accessory's craftsmanship.
Fourthly, some water pumps are refurbished from old parts, and in this case, the old paint can be found by simply removing the surface paint of the parts. It is best not to use such water pumps.
Fifth, when installing the purchased spare parts into the car, it depends on whether they can be compatible and have good compatibility with the parts. Generally, original factory parts can be well allocated to the car, while inferior parts are difficult to match well due to poor craftsmanship and large processing errors.
Sixth, in order to ensure that the assembly relationship of the water pump meets the technical requirements, some regular parts are wrapped with assembly marks to ensure the correct installation of the accessories. If there are no marks or the marks are blurry and cannot be recognized, they are not qualified accessories.
Seventh, a regular water pump assembly and components must be in good condition to ensure smooth installation and normal operation. Some small parts on the assembly are missing, which makes it easy to install and cause difficulties. These parts may be counterfeit.
Eighth, some important accessories, especially assemblies, are usually accompanied by instructions and certificates of conformity when leaving the factory to guide users in installation, use, and maintenance. Counterfeit assemblies generally do not have detailed installation instructions to guide these.
