Nov 18, 2011Winterize your irrigation equipment
It is the time of the year to winterize. Often, next year’s irrigation start-up problems are due to winter damage that can be prevented. Time spent now will prevent damage and lead to a better start on next year’s irrigation season. Inspection of the system now allows you to make improvements and repairs in the less costly off-season, and get irrigation problems out of the way for spring planting season.
Park pivots in safe location. When choosing a location to park the system for the winter, consider the three most common potential sources of damage: Wire theft is less likely in a visible but inaccessible area of the field; wind damage is less likely if the pivot points into or away from the wind direction, rather than perpendicular to the wind direction; and squirrel and other rodent damage to the span wire is rare when pivots are a few hundred feet from the tree line.
Drain pivots. Most of the currently designed pivots have automatic frost drains that drain the main overhead pipe. Plugged automatic frost drains can lead to major repairs if not caught in a fall inspection. Rock traps need to be cleaned and drained. Pivot supply lines, end-gun supply and hydro control hoses are often installed to allow drainage, but the hose may sag and hold water, which can lead to damage. Remember to cap all large openings into the system to prevent bird nesting.
Drain travelers and big guns. Travelers and stationary big guns often have portions of their system that may hold water. Drain and roll up hoses, unhook and drain end couplers and drain water-drive piston and motors that might be damaged by freezing.
Pump down or drain underground pipelines. Most underground pipelines are buried deep enough to prevent freeze damage, but often require pumping or draining enough water from them to empty the upper portion of Z-pipe risers and pump manifolds. This is typically done by purging the system with air or modifying a fertilizer transfer pump to the pump system at its lowest outlet or inlet points. Remember to cap all pipe inlets and outlets to prevent rodents from entering.
Drain the pumping plant. Drain the pumps and manifold to the lowest point they can hold water. Replace brass drain plugs if damaged. Well-designed pumping installations will be easy to drain without stripping drain plug threads or the need of air purging. Inspect gauges, supply and control wire for repair needs. Service the engine with attention to engine oil, bearing and seal lubrication. Check cooling system for adequate antifreeze level and concentration. Drain the fuel tank to reduce water accumulation and potential for theft.
Inspect and lock down electrical power supplies. Locking down electrical power supplies helps prevent vandals from turning wells and pivots on in midwinter, and minimizes potential electrical system damage. Inspect each electrical box in the system from power supply to the last pivot, or disconnect on the system line. Check for damage and holes that might be accessible to rodents. Now is an excellent time to inspect the grounding system and test resistance.
Create a winter work list for each system. While it is fresh in your memory, list the improvements and repairs needed for each system. As you are inspecting and winterizing your system, add any other areas needing attention to the list of repairs needed. Assign the repair to someone, whether an employee or the local irrigation dealer.
For more irrigation management information, visit the MSU website.
By Lyndon Kelly, Michigan State University