Monday 9 November 2015

Irrigator Maintenance – Sand

A little while ago I wrote about Sand Traps and how they should be inspected and cleaned regularly. This week we’ll look at the effect sand has on your irrigation system.

In general terms, sand inside an irrigation system = bad!

Sprinkler spray pattern

Just like sand-paper or sand blasting, sand suspended in water inside your irrigator is abrasive and will cause expedited wear on your system. This wear occurs anywhere exposed to the sand. It will start at the pump, causing impellors to wear faster, go through your mainline and headworks. If you have a mechanical flow meter, this will suffer. The sand then gets into the riser and makes its way along your span-pipes causing wear on the galvanising all the way along. Some of the sand will make its way up into the goosenecks and then down into your regulators and sprinkler nozzles, then onto the sprinkler plates. And guess what – it’s still abrasive and causing wear on these components too!

The main two problems caused by sand wear are
1.       Decreased life expectancy
2.       Decreased performance

As components like regulators and nozzles experience wear, they will start letting more and more water through, the more water that is going through, the greater the wear and the cycle continues. Your nicely calibrated system at the beginning of its life will soon start to over-apply water and as it is doing this it is also causing more wear on the sprinkler plate which will distort the sprinkler’s application pattern.

If you have a lot of sand in your system, other than emptying the sand trap frequently, you should also be aware that your system will need checking and re-calibrating more frequently to account for the wearing effect.

In order to mitigate some of the bad effects caused, you might want to consider a sand separation system such as the lakos sand separator filter pictured below. This type of filter will remove 98% of sand-like particle matter down to 200 mesh (74 micron) with low and steady pressure loss of only 0.137 to 0.413 bar.

Lakos sand separation system

For more information about sand filtration systems, contact your local Lindsay dealer.