Silent and Failsafe Overflow System

[BeanAnimal]

Waggs:

Those numbers are rough estimates of free flow through a bulkhead where the fliuid (water) is not being driven by any significant head. The system described here forces the primary drain to operate under full siphon. The flow rate through the siphon standpipe is MUCH higher than the chart you posted and is governed by the Bernoulli principle. There is a calculator on my site that will give you an idea of what flow rates can be expected in such systems.
http://beta.beananimal.com/articles/hydraulics-for-the-aquarist.aspx

 

[BeanAnimal]

Ok so I have two hopefully simple questions, first is about flow rate. Is the flow rate dictated by my return pump or is my return pump going to be determined by my speed at which it drains.

The flow rate is dictated by the return pump minus the loss from the plumbing that feeds the tank. The plumbing that drains the water back to the return pump has no effect on the flow rate. If the return plumbing is not capable of keeping up, the system will flood

Basically if i were to buy a 600 gallon per hour return pump would this system be able to operate correctly or do I need to look in the 1200+ range.

The system can be adjusted (via the VALVE) to accommodate lower flows than the maximum capacity.

Second, I wish I had the time to read ALL of this thread but sadly I don't, even if I could by the time I got to the end I would totally forget the beginning. Anyway in the original design beananimal used multiple sizes of fittings starting with 1.25 reducing to 1 then expanding to 1.5. He states the 1 inch bulk heads due to that is what he had. Would I be better off getting all from beginning to end at 1.5 or is the choke between the intake and the standpipe a useful part of the design.

The system works as published. If you wish to use 1.5" bulkheads you may. If you are only using a 600gph return pump, then they are extreme overkill and will cost more and take up a lot more space.

While you don't need to read every word of the entire thread, it would server you will to carefully read the project page at my site and then skim the bulk of the thread looking for anything that sticks out or touches on areas that you are not sure of.

If you don't want to spend another minute reading, then build the system exactly as published and you will be fine.

 

[reeflo/sequence]

Determining the pipe diameter is a function of two things..1-desired flow rate 2- length of pipe..it should never be determined by the size of your openings that why man invented adapters..generally speaking flow rates of 1500gph or less 1" is okay 5000gph or less 1.5" is ok..piping is like building a highway..you don't let the on ramp (openings) determined how many lanes in the highway..keep the pipes as wide as you can for as long as you can (your cardiologist will tell you the same thing)

 

[BeanAnimal]

I think we are getting sidetracked here with regard to "pipe size" and "bulkhead size" with regard to this system.

The system works as published WITHOUT modification and does so over a very broad range of flow rates from a few hundred GPH to several thousand GPH. It does so without the need to consider the rammifciations of pipe or bulkhead diameter.

The idea was (is) to allow people to build a silent and fail-safe overflow without the need to calculate flow rates, pipe sizes, head pressures, etc. The "extra information" has been provided for those folks interested in understanding the physics behind the system and/or those who have a need to modify the system to accommodate a different physical layout or higher than typical flow rates.

Hope that helps

 

[SoLiD]

Just wanted to thank you for your work on this project. I modified it down to 3/4" on my 40 breeder and it still worked flawlessly. Such an awesome design. Thanks again Bean. :thumbsup:

 

[BretCreager]

Thanks every one for the info, bean, I have read dozens of pages from the thread and just about your entire web site. You have done some great work. I still have not come across anything that lays out information that explaines why I woukd want a certin flowrate so the questions were hypothetical. Once I figure out what my desired flow rate to be at least I know I can make anything work. Thank you again

Bret

 

[dryworm]

does the drain pipes need to be above the water line in the sump or below it. or does it matter?

 

[jeffreylam1132]

Preferably, you want it about a couple inches below the water line to avoid the splashing noises. Does not affect performance whatsoever.

 

[RicoJ]

I love this thread. What I am interested in knowing why are many of you drilling your tanks for the beananimal overflow, but then doing an over the tank return. Why not drill for the return as well?

 

[rayn]

Going over the top for the return will allow less water to drain into the sump when it gets shut down. I drilled mine through the tank and return for a cleaner look like you are saying. Just need to have plenty of room in your sump.

 

[RicoJ]

Going over the top for the return will allow less water to drain into the sump when it gets shut down. I drilled mine through the tank and return for a cleaner look like you are saying. Just need to have plenty of room in your sump.

I see what you are saying. I am planning on drilling for the return and keeping the return near the surface. In case of a power outage to prevent back siphoning I will be using a George Fisher Wye Check Valve.

Rayn what size whole/plumbing did you use for your return? I am not certain of this. I will be using an Eheim 1262 (900 gph) as a return pump.

 

[SoLiD]

^^^ Yup what he said. Most people do that to prevent a ton of water from entering the sump from the back siphon that happens when you turn of the power to the return pump. I went the unconventional route and have my returns coming through the 4 bottom corners broken up by a Ocean Motion 4 way Squirt.

 

[SoLiD]

I see what you are saying. I am planning on drilling for the return and keeping the return near the surface. In case of a power outage to prevent back siphoning I will be using a George Fisher Wye Check Valve.

Rayn what size whole/plumbing did you use for your return? I am not certain of this. I will be using an Eheim 1262 (900 gph) as a return pump.

You could use 3/4 inch for the return and 1 inch for the drain with a pump of that size.

 

[rayn]

You can downsize your returns for sure. I drilled the same size and am using two returns each powered by their own pump. I did that just in case one pump went out the tank would still circulate.

 

[Mikei70]

You could always use loc-line or whatever on the return and have the end just slightly below the surface. I don't trust check valves.

 

[uncleof6]

does the drain pipes need to be above the water line in the sump or below it. or does it matter?

Yes they can be above the water line in the sump. However, this will most likely create some noise (from the volume of flow) which is against one of the design considerations: being silent.

Preferably, you want it about a couple inches below the water line to avoid the splashing noises. Does not affect performance whatsoever.

For silence, yes the outlets should be below the water line. However, a couple inches below the waterline will definitely affect performance, by making it more difficult to purge the air from the siphon line. It is important that this system be implemented as designed. Some (not all) deviations from this, lead to issues.

"All three standpipes are routed to the sump and terminate slightly below the waterline." "Slightly" has been defined in this thread, and many other places, as an inch or less.

 

[uncleof6]

I see what you are saying. I am planning on drilling for the return and keeping the return near the surface. In case of a power outage to prevent back siphoning I will be using a George Fisher Wye Check Valve.

Rayn what size whole/plumbing did you use for your return? I am not certain of this. I will be using an Eheim 1262 (900 gph) as a return pump.

As long as the check valve is not required to prevent a flood, you are fine with it.

Check valves have a failure probability of 100%. It is not a question of if, it is a question of when. The "when" will be the time you need it to prevent a flood. It may work today, it may work tomorrow, but it may not work next month, or next year. Despite maintenance, it takes nothing much to cause a check valve to fail--a small chip of coralline for instance.

The reason why folks design their systems minimizing the power out drain down, and maximizing the extra sump volume, is for a passive failsafe that is truly failsafe, rather than the false sense of safety provided by an active failsafe, such as check valves. If it is not needed--go ahead and use it. If it is needed, redesign the system so that it is not needed.

At that point, if it is not needed--don't waste your money on it.

 

[h9151105]

Will this overflow system also work silently with a nano wavebox? The reason why I am asking for is tat it will not a steady flow to the overfow box

 

[d2mini]

Has anyone extended the pvc pipe between the tank bulkhead and the sanitary T so that ball valves and rest of the plumbing is all on the other side of a wall (in the fish room)?

 

[afamousjohnson]

I like the idea of silent, and after trying to get through some 5000 posts of great info, and heavy critics-going to start off with thanks for taking the time bean. I am guessing within the 5000 posts I missed the 1 thing im trying to grasp off the thread. The majority is running the consept off of an overflow box?? I imagine it may be a common sense factor, but I can be humble enough to say "that sometimes it illudes me:spin1: "
I have a 90g with single overflow drilled with mega flow kit at present. I want to incorperate this into my system. I like that everything (drain/return) is out of sight as of now and would prefer to keep it that way as I moved from an overflow box to drilled from my last system with that in mind.
Questions:
Will I be able to incorperate this concept with only the two pipes-maybe making one with the valve and one for the failsafe or does it conflict not having the extra drain to help with the trickle off main overflow?? Have a friend who turned me onto this thread and he was talking on having only the main and the trickle so im guessing that to be without the failsafe drain which i am weary of after reading. I know then I would inevitably have to run a semi in view return-but in the end would rather have silent than a no visable pipping clean look:thumbsup: I guess I could always incorperate the failsafe to run on the outside of the tank behind overflow maybe????
I know this may all of already been discussed(and if so maybe someone could help direct me to its place in the thread) or that it may seem a bit of a mess or jumbled scinerio-but any hindsight if you understand the direction I am going for in an answer would be greatly appreciated:thumbsup:
Thanks again Bean and anyone contributing to the thread.