Saturday, June 28, 2008

Irrigation Trials

With the hay safely gathered in and dry fields under my feet I knew it was time to fire up the irrigation pump and make it rain. We have had a cool dry spring and early summer but now it is starting to warm up, and get crunchy underfoot. So on Tuesday I greased the motor bearings and fired up the pump, all seemed well so I switched it off and set about laying out pipe and guns on both sides of the river. The sheep pasture is getting dry now too and they will be out of pasture unless I got the water on soon. Once it was all set out I went back to the pump house with my little portable pump which we use to prime the main electric pump, primed the main pump and fired her up. The water surged through the pipes and out the nozzles on to the parched fields ,it felt good to me but probably more so for the grass. I move the pipe every 12 hours as I wish to get all the fields wet quickly and will slow up to a 24 hour move on the second time across the fields, this should ensure a more even growth on the hay fields and will improve the second cut.

All was well until the third day and for no reason the pump lost pressure and then its prime and so quit pumping water. This happened while I was moving settings and again during the middle of a shift for no reason. Not only was it loosing its prime but while it ran a rumbling sound could be heard and a vibration in the pipe work near the pump. Not good, and to top it all the forecast called for dry hot temperatures for the next two weeks. Panic and frustration were setting in as I had visions of long waits for parts followed by a big bill and a small hay crop. Now the only way to cope with this was to start with the small cheap fixes and work your way up. The only reason a pump looses its prime ( so long as it still has power to run it) is when air leaks into the system between the pump intake in the river and the pump. I checked all the valves and pipes and could hear no hissing or feel no sucking. I even went over the whole set up with a mister bottle of water spraying it to see if any moisture was sucked in, and still no luck.

After several times of priming and restarting the pump to see if it would run for more than ten minutes I noticed that the thin rubber inlet pipe from the small pump used to prime the big one was collapsing and I could hear a faint sucking sound which pointed to a faulty valve where the water used to start the main pump entered the system. I returned after a quick trip to the hard ware store with $20 worth of one inch valve and some Teflon tape, and after replacing the old valve and firing up the system it all worked like a charm. My nightmares of big bills and small hay crops were washed away by fresh cold river water from the nozzle of the irrigation gun and it never felt so good!

So next time you are told "not to sweat the small stuff" just remember the amount of air it took to stop that whole irrigation system was less than a mouse would use on a quick dash for cheese. I for one will always "sweat the small stuff" as its cheaper that way and often less stressful.

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