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here is how the overflow assembly looks like the one at my daughter's place:
http://the-hroost.com/public/2011/07/cat...flow-pipe/
The whole thing is movable. You have to lift it up and put it into your tank. Get the bubbles out, and then orient it just like it was before you touched it, and lift it straight up, over the edge of your tank, and lower it in place. Soon as you lift it up to place it back onto your tank, if you got all the air out, lookout, because it will shoot a big stream of water out, and will not stop until the water gets below the intake end inside the tank.
Jon in Keaau/HPP
Jon in Keaau/HPP
If your overflow siphon floats when you detatch it into the tank, it has lost prime. If it sinks like a rock, you are fine.
To prime it, submerge it and rotate it until air bubbles come out and it sinks.
Maybe a good idea to tie a string to it in case you drop it and it sinks to the bottom...
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You can't fix Samsara.
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One of the biggest problems with the overflows here is during times where the flow rate is very high (storms) it will generate a whirl pool on the intake, if that starts to spin hard enough to pull air into the pipe it will kill the siphon ("lose prime"). Adding a second overflow helps. Also I've found that putting several small holes in the upper top loop will draw in a little air and prevent strong whirl pools from forming because it will draw in a little air and slow the flow down. I think I saw this in the Keaau Ace Hardware as a recommendation and it has worked at stopping them from losing prime.
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As said just above, when too much water comes into the tank too quickly it can submerge the overflow inlet. Then like a sink or toilet the water will start swirling into the overflow pipe and create enough suction to draw air in as well as water and you loose the siphoning effect. Like household plumbing the system needs venting. After flipping my overflow set-up a few times to remove the air I added an open T fitting pointing up at the outlet, past the two U shapes that create the siphon. That also allowed me to plumb the water down to the ground and over 20' or so to drain in a better place.
Jay
Jay
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Well the mystery deepens... when I took the cover off the water had dropped to the normal level and the tank was no longer overflowing. I couldn't tell that there was any air in the overflow thing but I followed the instructions and spun it around 100 different directions while underwater and put it back. Will have to wait for the next big rain to find out if its working correctly.
ETA: Another component of the "mystery" is that we've had rains a LOT more severe than yesterday... so not sure why it happened this time.
Thanks everybody for their help!
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Strange. Must have worked the bubble/air lock out by itself. If it had air in it, you would have seen the big bubbles coming out of the ends as you turned it over in the tank. And, it would have made some pretty loud, "...bloop, bloop.." noises as the air/bubbles exited the pipes.
Jon in Keaau/HPP
Jon in Keaau/HPP
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Took our overflow out of the tank to clean it and didn't support it well enough. As I was lifting it out the bottom loop cracked at the 90 degree Elbow. I checked out the diagram listed by Birdmove above (Thanks for that- BTW). I have the replacement parts, made the repair and I am ready to re-install the overflow. My question is, Can I drop the Outlet height by 2" so the Tank level is a bit lower? Most of the diagrams I have been able to find show the inlet level pipe is roughly even with the lower opening on the T on the outlet side. Not knowing much about siphons and water pressure, will lowering the outlet by 2" affect the 'self-starting' draining of this overflow? Or will I need to drop the Inlet opening the same amount?
Also, is there any way to include pictures in a post or do you have to link to them?>
Super Stencils, Decals and more
Retired in Paradise
You can change the depth of the overflow siphon inlet to lower the water level in the tank. I had to do this because the overflow could not keep up with the gutters during intense deluges, so I lowered the tank level by almost a foot. That was enough buffer, and it hasn't overflowed since. Came close a few times, but intense deluges are usually brief.
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You can't fix Samsara.
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(07-23-2016, 06:51 PM)birdmove Wrote: A hose won't do it, because you have to get ALL the air out of the tube. You have to submerge the entire assembly in the tank, and then turn it over (like a summersault), which will let the air escape. I tried filling the tube with water. No go. It won't force the air bubbles out any other way.
As I described above, once I loosened the cover and pulled it back a bit, so I had some room, it took me all of a minute to bleed the air bubbles out and get the tube full. Tim had told me sometimes it doesn't go so easy, but now I know how to do it.
Jon in Keaau/HPP
Thank you, Jon, for your clear instructions! I'm an older woman and after 3 tries, I did it! Yay!
