Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
lapin
New member
As long as they are all the same material (PVC) they should be fine. Issues arise when you try to cement PVC to ABS.
Djbeasley05
New member
Does my inside everything looks good ?
On which one i need to put my valve ?
Thanks
Valve will be on your lowest elbow as it will be the full siphon
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Hal
New member
Run the siphon calculator and try to match your drain to the flow rate of your return pump (at whatever head you have).
I have a 250g tank and ran 1" for my siphon, durso, and return. I upsized my non-durso emergency drain to 1.5 inches just because I could. I figure it will give me a little extra margin in gph in draining if I ever need it.
My return pump will put about 1800 gph back into my tank and a 1" siphon at 11 feet of drop (into my basement) gives me something like 2200 gph. I'll adjust the siphon with a gate valve in the basement to get it to match the return rate from my pump.
Hal
New member
One more thing that I haven't seen mentioned yet: make sure that you have your drains a sufficient distance below the top of your tank to allow for the necessary flow rate. This is mostly a concern for the non-durso emergency drain.
For example, if the non-durso emergency drain is rated for 500 gph (based on diameter of the pipe), usually that assumes that it is being "fed" water at the full rate that it can handle. That will usually require an inch or two or more of water above the top of the drain pipe. If the top of your tank is only 1/2 inch above the top of your non-durso emergency, then it will likely never have the full 500 gph (in this example).
So in this example, if your return pump is putting 500 gph back into your tank, and your siphon and durso drains are completely blocked (hopefully a rare or never occurrence), the non-durso emergency drain could NOT keep up with your return pump, and the water will overflow the tank, onto the floor of your room.
I've scoured the internet but was not able to find a chart that showed how much water you need above a non-siphon, gravity drain in order to get the full flowrate.
For example, if the non-durso emergency drain is rated for 500 gph (based on diameter of the pipe), usually that assumes that it is being "fed" water at the full rate that it can handle. That will usually require an inch or two or more of water above the top of the drain pipe. If the top of your tank is only 1/2 inch above the top of your non-durso emergency, then it will likely never have the full 500 gph (in this example).
So in this example, if your return pump is putting 500 gph back into your tank, and your siphon and durso drains are completely blocked (hopefully a rare or never occurrence), the non-durso emergency drain could NOT keep up with your return pump, and the water will overflow the tank, onto the floor of your room.
I've scoured the internet but was not able to find a chart that showed how much water you need above a non-siphon, gravity drain in order to get the full flowrate.
Hal
New member
Finally, (and sorry for the fragmented and long posts), I've found it extraordinarily helpful to have my return pump wired to a float switch in my DT. I have the float switch inside my overflow. If the float switch trips (from high water because my BeanAnimal drain system failed), it shuts off electricity to my return pump. It's just another backup safety device to ensure no floods.
If you do this, just make sure that your float switch can handle the current going to your return pump. If not, the wiring gets a little more compicated with relays.
If you do this, just make sure that your float switch can handle the current going to your return pump. If not, the wiring gets a little more compicated with relays.
Personally, I would use 1.5” plumbing on anything over 150 gallons. It isn’t as much about the syphon being able to handle the flow. With the right circumstances a 1” syphon can handle around 2000 gph which is more then most people’s setups. It’s more about the open channel being able to handle flunctuation & to be able to handle more flow & remain quiet. A 1.5” open channel makes a big difference over 1”.
So that isn’t your tank u posted the picture of?
So that isn’t your tank u posted the picture of?
DougSupreme
New member
What is more important to the flow of a siphon? The weight of the water below the bulkhead? Or the weight of the water above the bulkhead?
My overflow is only about 6" deep, but I will have about a 3' fall. How do I determine my flow rate of the siphon?
My overflow is only about 6" deep, but I will have about a 3' fall. How do I determine my flow rate of the siphon?
What is your reasoning for wanting to know the flow of your syphon? I can’t help on your question but u can run a test to see what flow u have. In my case I have a 40 gallon sump that under normal operation runs with 25 gallons of water. So if I’m curious to know how many gph I am getting when I do a water change I fill my sump up to the rim which I know is a additional 15 gallons. Then I turn on the return pump & time how long it takes to get back to the normal water level & do the math to figure out the gph. In my case it takes right at 60 seconds to pump the extra 15 gallons of water from my sump. So doing the math it’s right around 900gph. I find it easier to figure how the gpm, then just multiply it by 60 to get the gph.
DougSupreme
New member
I want to have a good approximation of the flow through my drain prior to completion of the tank build. I'm going to use an inch and a half bulkhead for my 3 pipes but I want to make sure that I will have enough flow for my return pump
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Djbeasley05
New member
You can always dial back your return pump with an in-line valve. The more important questions are:
1:your tank size
2:how many times do you want to turn over
3:size/type or overflow box.
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DougSupreme
New member
The reason I want to know is so I can make sure my overflow is deep enough to create enough pressure for the siphon to flow enough. If it's not deep enough, I want to correct it now.
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DougSupreme
New member
The question of the hour is, what influences a siphon more? The water above the inlet or below the inlet?
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Djbeasley05
New member
Neither in your case. If you're building a coast to coast overflow, the pressure on any pipe in the overflow will be so small because of little water volume. Once the water level in the box reaches the emergency overflow per beans design the full siphon will start. You then just need to tune it per beans instructions. You might be thinking too much into it. I have a 4" tall coast to coast which fits two downturned 90s and an upturned 90 as emergency.
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Sisterlimonpot
Premium Member
From my experience, what determines when the full siphon begins is how deep you full siphon terminates under water in the sump. For instance if you're 4 inches below surface water will flow either through the emergency or the open channel and never obtain full siphon. However if it's 1" below surface it will be a lot more forgiving and siphon every time.
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