how to choose pump in irrigation system

water pump As the core power equipment of the irrigation system, the installation quality of the water pump is directly related to the operating efficiency, energy consumption and service life of the system. The following is the complete technical process, key parameter control and precautions for water pump installation, covering selection and design, construction and installation, commissioning and operation, and safety management.
1. Pump selection and installation location determination 1. Design parameter matching • Flow and head: Calculate the required flow (Q) and head (H) based on the irrigation area, crop water demand and terrain height difference. For example: • Flow formula:
(A is the irrigation area, E is the water consumption per unit area, T is the irrigation time) • Head formula: static friction safety
(H_static is the vertical height, H_friction is the resistance along the pipeline, and H_safety is the additional reserve, generally 0.3-0.5m)
• Power selection: Calculate the motor power (P) according to the formula and leave 20% redundancy. 2. Installation location requirements • Water source conditions: The water pump suction port should be away from mud, weeds and other debris. It is recommended to be ≥0.5m away from the water surface to avoid cavitation. • Terrain adaptation: Prioritize areas with higher terrain and good drainage to prevent rainwater backflow. • Power supply: The three-phase power supply voltage is stable (deviation ≤±5%), and the single-phase power supply power must match the rated power of the pump.

2. Pump installation construction steps 1. Foundation construction • Concrete foundation: • Size requirements: foundation length ≥ pump body length + 0.3m, width ≥ pump body width + 0.2m, thickness ≥ 0.3m. • Embedded anchor bolts: bolt diameter ≥ M20, depth ≥ 2 times bolt diameter, reserved hole size 50mm larger than the bolt. • Anti-seismic measures: lay a 10-15cm thick sand cushion at the bottom of the foundation to reduce vibration transmission.
2. Connection between water pump and pipeline• Suction pipe connection:• The diameter of the suction pipe should be ≥ the inlet diameter of the water pump to avoid insufficient flow caused by shrinkage. • Flexible joints (such as rubber flexible joints) should be used to buffer vibration and prevent stress damage to the pipeline. • Discharge pipe connection:• The discharge pipe should be equipped with a check valve (to prevent water hammer impact during shutdown) and a gate valve (to adjust the flow). • The distance between pipe supports should be ≤3m to prevent sagging.
3. Electrical wiring • Wiring specifications: • The wiring sequence of three-phase motors is consistent (U-V-W), and single-phase motors distinguish between live and neutral wires. • Grounding resistance ≤4Ω, protective grounding wire cross-sectional area ≥2.5mm². • Control cabinet installation: • The distance between the control cabinet and the water pump is ≤30m, and the protection level is IP54 or above. • Configure overload protection (the setting value of the thermal relay is 1.2-1.5 times the rated current of the motor) and leakage protection (operating current ≤30mA).
3. Pump commissioning and operation management 1. Inspection before trial operation • Mechanical inspection: • Check the tightness of the anchor bolts, and the concentricity deviation between the pump shaft and the motor shaft is ≤0.05mm. • There is no leakage at the pipe connection, and the valve opens flexibly. • Electrical inspection: • Measure the insulation resistance (≥500MΩ) and confirm that the power supply phase sequence is correct (the rotation direction is consistent with the mark).

2. No-load test run • Start-up process: 1. Close the outlet valve and open the bottom valve of the suction pipe. 2. Start the motor by jogging and observe whether the rotation direction is correct (clockwise from the motor end). 3. Open the outlet valve gradually and record the current, voltage, speed and other parameters. • Monitoring indicators: • Current: ≤110% of the rated current; • Vibration: ≤0.1mm (double amplitude); • Noise: ≤85dB (A).
3. Load test run • Flow and pressure test: • Use flow meter (such as electromagnetic flow meter) and pressure gauge (range 1.5-2 times working pressure) to monitor actual parameters. • Adjust the gate valve to make the flow close to the design value and record the pump efficiency curve. • Abnormal handling: • Current overload: Check for impeller obstruction or pipe blockage, and clean up foreign objects. • Insufficient water output: Check for air leakage in the suction pipe, filter blockage or impeller wear.
IV. Safety protection and long-term maintenance 1. Safety protection measures • Physical protection: • Set up guardrails (height ≥ 1.2m) and warning signs (such as "high voltage danger") in the pump room. • Lay insulating mats on the floor of the operation area. • Electrical safety: • Configure leakage protection switches (operation time ≤ 0.1s) and test the reliability of operation regularly. • Disconnect the power supply during thunderstorms and install a lightning protection device (SPD).

2. Maintenance and management points • Daily inspection: • Record operating parameters (current, voltage, flow, pressure) daily and compare with historical data. • Check bearing temperature (≤75℃) and grease condition (replace every six months). • Regular maintenance: • Clean the filter and check valve every quarter to remove sediment. • Calibrate flow meter and pressure gauge every year to ensure measurement accuracy.