Spring System Checkup

Performing regular maintenance of your irrigation equipment should include a pre-season checkup. The expectation should be that component wear happens and it sometimes results in less uniform water application, and increased energy use.

In addition, to reduce the risk that wear and tear will result in untimely breakdowns, worn components should be identified and replaced now so that the systems are ready for use during the growing season.

One of the best ways to identify worn components such as sprinklers, pumps or irrigation systems is to keep good records.

  • Recording the outlet pressure, flow rate and energy use on a regular basis (at least once per month) provides an excellent means of evaluating pump and motor performance.
  • Operating pressure should be recorded when the pivot is in the same position each time since the pump will produce different outlet pressure when the system is facing uphill than when the system is facing downhill.
  • Systems that do not have pressure regulators to maintain sprinkler pressure will also have different flow rates. Record the flow rate and operating pressure in a notebook so that you can compare current flow rate and pressure to last year's and the years before.

Each irrigation system will have a number of areas to lubricate, or parts that may need to be replaced prior to the first irrigation. It is impossible to list them all, but the list should include:

1) Change the engine oil and filter,

2) Replace the air and fuel filters,

3) Grease drive shafts on pump, and motor,

4) Check spark plugs on gas, propane or natural gas motors,

5) Drain, flush and refill the cooling system,

6) Refill the drip oil reservoir and allow oil to drain into the drip line based on pump column length,

7) Ensure that the right-angle gear head is free moving and clean and lubricate non-reverse pins,

8) Run the motor at the normal operating speed for 45 minutes,

9) Start the pump and walk along system looking for malfunctioning sprinklers. Nozzle wear depends on the quality of the water and the system operating pressure. As a rule of thumb, sprinkler replacement should be considered after approximately 10-12,000 hours of operation. Be sure to replace malfunctioning nozzles with ones listed on the computer printout you received from the manufacturer.

10) Check chemigation pump and safety equipment operation. Check hoses and replace if cracking is noticeable.

Each irrigation system is equipped with a number of safety switches to shut the system down in the case of failure. Now is the best time to ensure that all these controls function properly. Run the system through a set of conditions that should cause each of the system safety controls to function.

These items ensure that the system will operate, however, a more difficult task is to determine how efficient the system is functioning.

  • Periodic pumping plant evaluations will aid in identifying if the pumping plant is operating at an optimum level. The evalution should identify the overall operating efficiency but equally important it should provide the pump outlet pressure, system flow rate, and the energy use rate required at the time of the evaluation. This information will provide a base point to compare with future operating characteristics.
  • If you have recent pumping plant evaluation results, simply compare the information discussed above with the evaluation results to determine if the system is becoming less efficient over time.

In summary, frequent use of record keeping practices to make comparisons between previous energy use and current energy use can help identify when maintenance is required on the pump or power supply.

  • Visual inspection of sprinkler operation can ensure that water application uniformity is adequate.
  • Finally, testing of safety switches will ensure, that should a system component fail, the system will be shut down prior to causing major damage to the irrigation system.