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Contributor

what is the life span of a center pivot irrigation unit

 
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16 Replies
Veteran Advisor

I don't know

My brother bought a used unit, from the late 1970s, and its still going.

 

Generally, I think you can go 10+ years with little to no repairs, and then you start having to replace things like drive motors, gearboxes, and electrical contactors, or valve seals on a hydraulic drive.

 

If you are willing to replace drive components, electrical contacts, tires, etc, it will literally go until it rusts away to the point of being structurally unsound.

 

I would avoid a pivot with a long overhang, for maximum longevity.   The wind makes it 'sway', and when they get older, some of the attatchment points of the overhang, can get metal fatigue from the flexing, and crack/break the attatchment points.

The 'overhang' is the section of pivot, that hangs past the wheels of the end tower, supported by truss rods or cables.

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Senior Contributor

Re: I don't know

Our oldest pivot was new in 1983 and it was a three tower towable Valley. We towed it to four different pivot points for several years. Then to just two points until about 6 years ago and is still watering one 20 acre half circle. What I'm saying is this pivot was "drug" all over the place and is still working. We also have three seven tower pivots that were new in the late 80's.

 

So they last a pretty long time when properly maintained. We are up to 15 pivots now, ranging from that 30 yr old one to a couple 2 year old ones. We only have two more small fields that could be converted from gravity irrigation to pivot irrigation. We may start replacing the older pivots slowly, but they actually are not really giving us much trouble. If they didn't have end guns on the end we wouldn't have much trouble at all  Smiley Happy

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Veteran Advisor

Re: I don't know

I might mention, if you think end guns are a problem, check out corner systems!

I don't have one, but have helped neighbors deal with them.   If a safety switch fails, the pivot will actually tip itself over if the corner arm gets stuck, or has a malfunction.

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Senior Contributor

Re: I don't know

Actually we have 4 corner systems. And yes you're right. We figure a corner system has four times the problems a straight system does.  We haven't had one tip over the way you describe , but they are much more susceptible to tipping over in a storm than the main spans.

 

 We added a corner to a system a year ago and figured it paid for half of itself just this last summer. Usually it is hard to justify the cost of a corner to just irrigate 16 acres in the four corners. Then a year like last year comes along..... 

 

 

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Veteran Advisor

Re: I don't know

Do you have an idea, really, of how much more a corner arm catches, than an endgun, with a good booster pump?

 

What we have done, on my pivot, since it is downhill to the corners, is to put what they call a 'dump valve' at the end of the pivot, which opens up a 1 1/2 inch pipe to a 'bubbler', which basically flood irrigates the corners.  You have to ridge the crops lightly, so the water follows the row, rather than taking its own path, but it gained me about 100 BPA in the corners, over not irrigating, and I got it setup for under $1000.

 

 

Senior Contributor

Re: I don't know

Good idea, Nebr. I have seen those dump valves on a couple pivots around here. We have three pivots where the placement of the well allows us to gravity irrigate a corner or two with pipe.  

A "normal" quarter section pivot leaves about 5 acres in each corner. A corner system on that size of pivot leaves one acre. That is with each having 100 ft. End guns.

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Contributor

Re: I don't know

We are in IN and see pivots in Neb. For sale used .  Most are in the 80's  would it be cost effective  to use one of these units for a half circle.  Keeping in mind we will not run the hours per year that most do in the western states

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Senior Contributor

Re: I don't know

We have done this three times -- buying a used seven tower system for an 80 acre field. It cuts down on the cost per acre over a new one for just 80 acres. Another thing we have done is go together with a neighbor that has the 80 next to us. That way you split the cost. In fact four of us went together to buy a new full system for four 40's that adjoin each other. Sometimes it takes a legal agreement to cover things like a buyout.

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Veteran Advisor

Re: I don't know

People do it all the time.  It doesn't cost any more to haul, and set up a used one, than a new one, but you will have the extra cost involved, with taking it down.

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