Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
rickztahone
New member
the first few pages of the OP was a lot of banter back and forth and Bean being banned and reinstated :sad2:
sleepydoc
Team RC
This is a problem with a lot of stuff - it's in the thread somewhere (or another thread,) but it's so difficult to find that people end up asking again. A forum like this is great for asking questions and having discussions, but horrible for reference.
I've entertained the idea of setting up a wiki or web page on my own to serve as a reference for topics like this, but haven't had the time to do more than think about it. Maybe some day...
I've entertained the idea of setting up a wiki or web page on my own to serve as a reference for topics like this, but haven't had the time to do more than think about it. Maybe some day...
uncleof6
Active member
How one sees something, depends on how you look at it: what one chooses to focus on. I read it, (the very same things), I got what was needed out of it, implemented the system, it worked, and here we are today.
Aside from that, you can get the short version on bean's website. 90% of what you need to know to implement this system and have it work right out of the box, is on bean's website. The rest has been repeated so many times, that most any question should have an answer within an hour, if one really chooses to look for it. Heck you can look at the pictures, and figure it out.
http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx
The guarantee applies to "as designed."
uncleof6
Active member
We've talked about this. But again, I just went through this (the hole placement) with you, which is fine. Next week the question will be asked again, maybe tomorrow. Now we are off topic on this track, adding to the problem.
I think that the biggest problem is a little thing called patience. Everyone wants it right now: they want their tank to support anemones right now. They want the answer, right now. They would rather spend someone else's time, than their own, doing homework.
There is a little radio button on the search page, that can search for posts, and pull them up in the thread they are in. I did it a second ago, and found one where the other poster had one of the dimensions wrong, and I did not catch it.
I am not going to disagree that this thread is a bear though.
AdamPLawrence
New member
I'm too lazy to reread it so I'll just ask: why did Bean get banned all those years ago?
mmn
New member
Seriously off topic, and this thread is already so long. Please....
rickztahone
New member
Uncle, your guidance has been very helpful, but u assure you I read more than an hour and there is no way that information can be gathered in that amount of time.
There are small tidbits, or rather, the other 10% you refer to that are harder to come across to. All I'm saying is, for a project that has been emulated so much and has soooooo many pages on, you'd expect a consolidated area where you can find this information.
I'm all for finding this info on my own, and I will actually go back and read more, but just be aware that there is so much "fluff" that it is difficult to read page to page.
With that I will shut up because I'm not trying to stir anything up. I'm merely making an observation as a moderator for different forums.
Thanks
There are small tidbits, or rather, the other 10% you refer to that are harder to come across to. All I'm saying is, for a project that has been emulated so much and has soooooo many pages on, you'd expect a consolidated area where you can find this information.
I'm all for finding this info on my own, and I will actually go back and read more, but just be aware that there is so much "fluff" that it is difficult to read page to page.
With that I will shut up because I'm not trying to stir anything up. I'm merely making an observation as a moderator for different forums.
Thanks
How one sees something, depends on how you look at it: what one chooses to focus on. I read it, (the very same things), I got what was needed out of it, implemented the system, it worked, and here we are today.
Aside from that, you can get the short version on bean's website. 90% of what you need to know to implement this system and have it work right out of the box, is on bean's website. The rest has been repeated so many times, that most any question should have an answer within an hour, if one really chooses to look for it. Heck you can look at the pictures, and figure it out.
http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx
The guarantee applies to "as designed."
m1k3
New member
I downsized my primary to 1" and it settles out at 7 seconds now. Yeah, maybe I should have gotten the compact 5000. I may try to sell this one and get a 5000, I was shooting for around 550 GPH, I doubt I am too far off of that number. The 5000 starts out at 660 and goes up to 1320, so I could turn it down and still get the little flow I want with some room for my flow if I chose to increase or to adjust as the pump and return line get gunked up. I am in the slow flow sump camp.
uncleof6
Active member
No. The Eheim 5000 compact starts out at 1321 @ 0' of head, and drops to 0 at ~9.8' of head. The 660 - 1321 is the adjustable flow, @ 0' of head. So the curve runs from 660gph @ 0' to 0gph @ an unspecified pressure head. What the pump is actually going to flow depends on the static lift, and the friction loss. Together equal the total dynamic head, which is the number that gets applied to the flow curve, but with the output turned down, there is no flow curve. You are looking at numbers that have no validity in the real world. The only way you are going to know what the pump is doing, is to use a flow meter or weir calculations. Or, engineer the system, and select the appropriate pump for the system, instead of trying to engineer the system for the pump you rushed out and bought.
Also, when the pump and return line get gunked up, it is time to clean the pump and return line, not turn the output of the pump up. Adjusting the pump output, would not be the best husbandry for the system. Cleaning pumps, return lines, and drains, should be a regular maintenance routine. And no, you don't need to take the plumbing apart to clean it, unless you painted yourself into a corner.
cryptic_grower
New member
I have to admit it has taken me a long frigging time to read this thread but it has given me every bit of info I needed to feel 100% conformable setting up my plumbing system! Every question I had and more was answered , at least 3x.
Thanks Bean, Uncle and countless others.
Thanks Bean, Uncle and countless others.
uncleof6
Active member
To really get into this, you have to know the differences between pressure, (depth) zero pressure or atmospheric pressure, and low pressure (below atmospheric.)
Cavitation is happens when water hits its vapor pressure, and it "boils." This can happen with any siphon, but usually, after lifting close to the limits dictated by the hydrostatic pressure at the siphon suction. (Atmospheric pressure + pressure; psia) At sea level real world, this would be ~34' of lift, (20' practical limit; elevation change from water level) to the crest of a dam for instance. The distance it can lift is variable depending on elevation (local atmospheric pressure.)
Cavitation makes itself known as a grinding noise, a noise that closely resembles gravel being moved around in a cement mixer. It is due to the fluid being vaporized because of low pressure and then suddenly collapsing due to high pressure produced by a pump impeller for example or the increase in pressure that occurs at the outlet of a valve.
That said, in the BA system, we are not really lifting water vertically in the siphon line. It is strictly pressure head, (though if adjusted low enough we could lift 1/2" or so, but a vortex would probably form.) So it is unlikely that cavitation would be caused by the pressure differential. Flowing from a low pressure area (top of the siphon) to a higher pressure area at the outlet of the drain line, which would be the hydrostatic pressure at the outlet, depth of the outlet. (Or atmospheric pressure if not submerged.) Siphon for our purposes is "designed to run full (no air) and under a pressure differential." There is no lift component. So it is not a "siphon" per se, but the term is used to describe the mode of operation above. Remember that though it looks similar to a "u tube" it is not really, and the inside diameter is smaller than what you see on the outside. (especially going through the bulkhead, out of the tank back, which would be the "crest.") The "lift" is to the bottom of the inside diameter, (or the weir,) inside the elbow or tee, what have you.
With water just flowing in the open channel, the lift on the siphon would be zero. The correct adjustment point for the BA.
Where you will see cavitation in the drain line is just past the valve (a restriction in the drain line.) Because at that position the pressure at the inlet of the valve is low, it is further reduced as the fluid goes through the body of the valve and the fluid boils. The small vapor bubbles that are produced are rapidly compressed and collapsed due to the increase in pressure as it comes out of the valve. This collapse produces a shock wave that impacts the valve body producing noise and in some cases, severe erosion. You certainly don't want a valve at the crest of a siphon.
It is usually only an annoyance in an unusually long drop, for instance into a basement from the first floor, or higher. With higher pressure differentials, air can be sucked in past the valve seals as well. (See Venturi valve operation.) Same can happen in a pump volute if not plumbed correctly, (generally extrenal pumps only) but the pump will be damaged rather than just being an annoyance.
Placing the valve as close to the sump as practical, alleviates the annoyance.
If the drain sucks in air at the inlet, you will get bubbles, and the siphon won't start, but that is not really "cavitation," rather just not a good thing to allow to happen. That is the reason for the down turned elbow.
Cavitation is happens when water hits its vapor pressure, and it "boils." This can happen with any siphon, but usually, after lifting close to the limits dictated by the hydrostatic pressure at the siphon suction. (Atmospheric pressure + pressure; psia) At sea level real world, this would be ~34' of lift, (20' practical limit; elevation change from water level) to the crest of a dam for instance. The distance it can lift is variable depending on elevation (local atmospheric pressure.)
Cavitation makes itself known as a grinding noise, a noise that closely resembles gravel being moved around in a cement mixer. It is due to the fluid being vaporized because of low pressure and then suddenly collapsing due to high pressure produced by a pump impeller for example or the increase in pressure that occurs at the outlet of a valve.
That said, in the BA system, we are not really lifting water vertically in the siphon line. It is strictly pressure head, (though if adjusted low enough we could lift 1/2" or so, but a vortex would probably form.) So it is unlikely that cavitation would be caused by the pressure differential. Flowing from a low pressure area (top of the siphon) to a higher pressure area at the outlet of the drain line, which would be the hydrostatic pressure at the outlet, depth of the outlet. (Or atmospheric pressure if not submerged.) Siphon for our purposes is "designed to run full (no air) and under a pressure differential." There is no lift component. So it is not a "siphon" per se, but the term is used to describe the mode of operation above. Remember that though it looks similar to a "u tube" it is not really, and the inside diameter is smaller than what you see on the outside. (especially going through the bulkhead, out of the tank back, which would be the "crest.") The "lift" is to the bottom of the inside diameter, (or the weir,) inside the elbow or tee, what have you.
With water just flowing in the open channel, the lift on the siphon would be zero. The correct adjustment point for the BA.
Where you will see cavitation in the drain line is just past the valve (a restriction in the drain line.) Because at that position the pressure at the inlet of the valve is low, it is further reduced as the fluid goes through the body of the valve and the fluid boils. The small vapor bubbles that are produced are rapidly compressed and collapsed due to the increase in pressure as it comes out of the valve. This collapse produces a shock wave that impacts the valve body producing noise and in some cases, severe erosion. You certainly don't want a valve at the crest of a siphon.
It is usually only an annoyance in an unusually long drop, for instance into a basement from the first floor, or higher. With higher pressure differentials, air can be sucked in past the valve seals as well. (See Venturi valve operation.) Same can happen in a pump volute if not plumbed correctly, (generally extrenal pumps only) but the pump will be damaged rather than just being an annoyance.
Placing the valve as close to the sump as practical, alleviates the annoyance.
If the drain sucks in air at the inlet, you will get bubbles, and the siphon won't start, but that is not really "cavitation," rather just not a good thing to allow to happen. That is the reason for the down turned elbow.
Wow! Thanks Uncle. Very impressive. Maybe I should have phrased the question as to whether the box would be deep enough to keep the full-siphon line from creating a vortex and sucking air (like a whirlpool?) from the surface. I just want to make sure that the siphon has enough space vertically so that this doesn't happen.
uncleof6
Active member
4" box is not practical. Minimum box height is ~ 5". If external, you need taller. Folks making minimum sized stuff are just creating problems for themselves.
That said, it is not the depth of the box that will affect the vortex, it is the distance from the water level to the inlet to the siphon. In *most* correctly set up systems, this will not be an issue, due to the down turned elbow. Pays to use 1.25" elbow inside the box...
That said, it is not the depth of the box that will affect the vortex, it is the distance from the water level to the inlet to the siphon. In *most* correctly set up systems, this will not be an issue, due to the down turned elbow. Pays to use 1.25" elbow inside the box...
Thanks Uncle. I can have them make the box 24"x4"x5" deep. It's an internal box, so with a weir height of at least 1/8" I can make the entrance to the siphon (down-turned elbow) up to ~5" below the water surface.
Do you mean that I should have 3/4" clean ace from the bottom of the box to the bottom of the elbow?
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