How do you maintain a center pivot irrigation system?

A center pivot irrigation system, also known as a pointer-type or circular irrigation system, is suitable for large-scale agricultural irrigation such as on farms. Carrying out good preventive maintenance and care on the equipment before irrigation or during the irrigation season is a crucial matter, so how should a center pivot irrigation system be maintained?

Pre-season maintenance

1. Center axis part

There are two grease nipples at the head of the center axis, which need to be greased once a year or every 1000 hours of use, using multi-purpose grease.

2. Wheels and gears of the movable type

In a movable-type system, there is a grease nipple at the gearbox; grease needs to be added here once every three moves, or once a year if the system is not in operation, which can prevent water from entering the bearings.

3. Oil

After the first season of use, replace the oil in the wheel gearboxes and gear motors. After that, check the oil once every three moves, or once a year if not used year-round. Then at the start of the next irrigation season, the oil level in the gearboxes must be checked.

For the center point, fill it with SAE140 oil until its height reaches the screw (3.5 liters). The oil type required for the VXP-type central gearbox: SAE50 (1.75 liters each)

Post-season maintenance

(1) Drain the water from the spans and pipes. At the center axis: close the valve below the pressure gauge and drain all the water. Open the ball valves at the joints of each span, including between the center axis and the first span as well as between the remaining spans, and drain all the water from the pipes. After completing these operations, return the ball valves to the middle position (between open and closed, to prevent freezing from damaging them). Open and clean the sand guard ring. If a sprinkler gun with a stop or automatic stop valve is installed on the axis, drain the water from the electric valve filter housing, disconnect all control hoses and drain the water from them, then reconnect them to prevent dirt or insects from entering. Drain the pressure valve and sprinkler gun to prevent freezing damage.

(2) Grease the shaft elbows and protect all the screws

(3) Drain the oil from the wheel gearboxes and central drive every 1200 hours or 2 years. The water inside these gearboxes should be drained frequently (every 2 months), otherwise the water will become more concentrated and seep in, causing: slowly loosen the drain plug, and when there is oil, let the water drain out and tighten it; then check the oil level, making sure the oil must cover the gearbox screw, and the central drive must be filled to the height of the oil filler plug. When the parts are installed on the tower, the oil level must be checked.

(4) Check whether the wheel nuts are tightened and protected with oil, and inflate the tires to a pressure of 2.5 bar to prevent the tires from cracking in winter.

(5) Check the span connection rods and round clamps, and apply oil

(6) Circuit control panel and tower control box: keep the isolation switch in the open position, check the wiring connections, protect the circuit components from the effects of water spray, lock the door, check the cable sealing tubes, and check the tower control box housing

(7) Check the performance of the electrical switches (automatic reverse, safety switches, etc.) and protect their gaskets