SIPHON TIME
With the Honda warmed up I set the pump running. I guessed water was going up the hill as the engine sound gradually changed from easy-peasy to a steady determined throb and I set off along the pipeline to double check each joint as the water ran through. All looked good and by the time I made it over the hill water was pouring out of the other end of the pipe. So far so good. Walk back to the sump, pull out the pump connection while keeping the ends under water. A little stiff, pull and twist and pull again and out of the sump came the pipe and into the sump goes my boot. Oh dear, I had just let air into the pipe and water in my boot :ashamed: Empty boot and start all over again.
It was a nice day and I'm the patient type, so nothing really lost. Right, again, pump on pipe, water running, squelch back over hill to check it's coming out, yep, back to sump. This time I made double sure I kept the pipe in the sump as I pulled out the pump. I put my palm over the end and could feel it tug hard. SIPHON
Found the end of the flexible suction hose from the filter box and tried to get it on the pipe. It was a bit tight and awkward to get on from my position on the bankside. I probably tried too hard to keep the other foot dry when I should have accepted fate and climbed fully into that sump from the outset, but we live an learn and eventually the hose went on. Turn off the pump and peace descends again. Back over the hill to the discharge end to see it running - except it wasn't a discharge end. It was more like an empty-pipe-laying-on-damp-grass end.
The siphon had stopped. :confused3: What had I done wrong, apart from wearing boots instead of waders
Back to the sump and check filter. Nope that looked ok. Had I miscalculated the relative heights of each end of the pipe ? Didn't think so. I remembered something I had read about dissolved gasses preventing siphons from working. You know how bubbles fizz out when you open a bottle of lemonade ? The same thing can happen in a siphon, gas is released because the pressure in the pipe is lower than outside. Was that it ? Why hadn't I looked into that in more detail. If this water was so gassy it couldn't be siphoned, I would need to go out and buy a few things - lots of fuel and a big slice of humble pie to eat while I tended the pump for days on end.
There could be a much simpler answer. I had put my hand over the end of the pipe to check it was running and then probably obstructed it again as I fumbled with the filter hose. In that time water would still be running out of the discharge end. Could that have been long enough to let air up the outlet ?
Ok, try again and this time make it a smoother change over. Also I reasoned that if I partially bunged up the discharge end until I got it started, it may help restrict the flow enough to prevent air coming back in while I swapped over the pipe in the sump.
Engine on, pump on, let water run for 10 minutes (I'd had enough walking by then to care about checking it was coming out on the other side), smooth changeover, turn pump off, walk up the hill, down other side.
Oh yes, running water. :dance1: Pulled out the restriction and the water came gushing out. :dance1::dance1::dance1:
