Silent and Failsafe Overflow System

[Floyd R Turbo]

Kstatefan The water level could be just about anywhere depending on where you set the drain valve. But if that yellow/brown box is your overflow box, you're gonna overflow it on startup.

Siphon line in an external box needs to be as low as possible. Really it doesn't matter if it's 1" or 10" below the water. E drain min 2" from top of box. OC needs to be low as well, top of elbow below the top of the E drain.

More along these lines

But the correction to the above is that you can have the OC at the same level as the siphon, and it won't siphon until the airline gets occluded. The lower you set it relative to the operating water level of the box (which is controlled by the siphon valve) then the more it will flow at that water level.

So my method is to set the siphon all the way down and then the horizontal center of the OC around the point where I want it to operate, so that the water is about 1/2 way up the horizontal circular cross-section of that double 90

JMO

 

[sleepydoc]

My question is why go for larger pipe if the max flow that will go through is dictated by the bulkhead diameter? Is this to make the open channel more effective ? My last question is should the pipes only drop down straight into the sump or is ok to have a 45degree elbow near the end to help get the pipes into the sump which is under the tank? Otherwise i will have to have the sump protude out from under the tanks footprint to get the pipes to drop straight in? Many thanks for you input on this.

Flow resistance imparted by the plumbing is additive, so the total resistance is the resistance of the bulkhead plus that of the pipes, so increasing the size of the pipe without increasing the bulkhead actually does make a difference. In addition, increasing the size of the open channel drain can significantly increase the amount of water it can carry quietly.

45º bends are OK. Horizontal runs can cause problems by preventing the system from purging the air at startup, but most people (myself included) have some 45's and don't have any issues.

 

[KStatefan]

Kstatefan The water level could be just about anywhere depending on where you set the drain valve. But if that yellow/brown box is your overflow box, you're gonna overflow it on startup.



JMO

Thanks. The box does not matter in this was just on that part of the drawing when i copied it to the jpeg.

 

[Bent]

Flow resistance imparted by the plumbing is additive, so the total resistance is the resistance of the bulkhead plus that of the pipes, so increasing the size of the pipe without increasing the bulkhead actually does make a difference. In addition, increasing the size of the open channel drain can significantly increase the amount of water it can carry quietly.

45º bends are OK. Horizontal runs can cause problems by preventing the system from purging the air at startup, but most people (myself included) have some 45's and don't have any issues.

That's all I needed to hear. Gratzi

 

[sleepydoc]

My standpipes are sitting at about 45 degrees, do they have to be straight up and down for this to work?

I just can't figure out if I'm looking at that picture straight... :spin2:

It should be fine. The main issue is whether the siphon channel can purge the air. This depends on the configuration of the plumbing, the pipe size and the flow. As I said in the post above almost everyone has at least a short stretch of angled pipe and doesn't have issues with it. Horizontal stretches are the big problem.

 

[sleepydoc]

Really it doesn't matter if it's 1" or 10" below the water. E drain min 2" from top of box. OC needs to be low as well, top of elbow below the top of the E drain.

Well, that depends on the flow and your pipe size. If you have it too close to the surface, it will tend to suck air from vortices that form from the surface. You also need to make sure it far enough off the bottom of the overflow box so it doesn't restrict flow.

 

[Floyd R Turbo]

Besides that, yes. I was speaking in vague generalities in order to provoke a response. And it worked

 

[Dandaleh]

Flow resistance imparted by the plumbing is additive, so the total resistance is the resistance of the bulkhead plus that of the pipes, so increasing the size of the pipe without increasing the bulkhead actually does make a difference. In addition, increasing the size of the open channel drain can significantly increase the amount of water it can carry quietly.



45º bends are OK. Horizontal runs can cause problems by preventing the system from purging the air at startup, but most people (myself included) have some 45's and don't have any issues.

Ok thanks for that . What do you think regarding 2.5inch bulkheads going to 3inch pipe? Im trying to find out how much flow this will handle ? The pumps I have will produce 10k gallons / hour at 2m head height

 

[sleepydoc]

That should be fine - a 2.5" pipe can theoretically flow about 18,000 GPH at a 2 m head height, so you have plenty of margin for error

 

[Dandaleh]

Did you mean 3" pipe ? Uncleof6 recommended a 2.5" bulkhead and 3" pipe ?

 

[Dandaleh]

Just want to make sure I'm not going wrong with those sizes?

 

[sleepydoc]

Did you mean 3" pipe ? Uncleof6 recommended a 2.5" bulkhead and 3" pipe ?

I ran the calculations with 2.5" pipe. 3" pipe will flow even more.

Note that I have no experience with tanks of this size or systems using this kind of flows. As uncle said, this is beyond the scope of a normal hobby tank, so any advice should be taken with that caveat.

 

[Dandaleh]

Ok fine , so I could do 2.0 inch bulkhead with a 2.5inch pipe which would handle up to 18000 gallons per hour ? Out of interest do you refer to a tool or website that's does the flow calc ? Yes it's a bigger tank but the principle is the same , just need to ensure the pipes can handle enough flow for the pumps

 

[Dandaleh]

Appreciate your help on this

 

[sleepydoc]

There's a head loss calculator on RC's home page. It probably won't be much help, though. Head pressure is dependent on flow, and flow is dependent on your pumps flow/pressure characteristics, so most head loss calculators use an iterative approach based on known pressure-flow characteristics for a given pump, and your pump and flow rates likely won't be in the calculator.

In terms of flows for a siphon, bean animal has a calculator on his web site that will give a rough estimate of flow through a straight siphon. It ignores any elbows, bulkheads, etc, so it tends to estimate high, but it will give you a place to start

 

[Bent]

So why exactly would my open stand pipe be siphoning and my siphon stand pipe just trickling? It really doesn't make much sense to me.

The open stand pipe shouldn't be siphoning since it has the tube sticking out the top of it, right?

All 3 exits in the sump are under water. Would that be a reason?

 

[SaltwaterNoob17]

:strooper:

you should talk with metamorphis - he/she is putting together a 500 gallon tank, too.

To (try and) answer your questions:
If you do a bean overflow, going down, under the slab then back up to the sump will be problematic in many ways. Beyond the logistics and expense of setting it up, cleaning and troubleshooting will be difficult and it is more difficult to get a siphon established with a horizontal run; I would have serious concerns about the function of the siphon drain with this configuration.

The resistance of the pipe is a potential concern, but probably not one that can't be overcome. There are sites that go over the equations; It's late and I'm tired, so I can't think of them off hand, but it's definitely doable.

Thanks, sleepydoc. Yeah, I had a feeling that going under the slab wouldn't be smart for this scenario. I know that I want my sump for the aquarium located in that separate 'fish room'. What's the ideal plumbing design in that case?

 

[sleepydoc]

Thanks, sleepydoc. Yeah, I had a feeling that going under the slab wouldn't be smart for this scenario. I know that I want my sump for the aquarium located in that separate 'fish room'. What's the ideal plumbing design in that case?

Well, it depends on the setup.

Ideal is to have the fish room immediately behind or underneath the tank, but it sounds like your fish room will be some distance away. It may be possible to do a bean setup in that scenario, but I honestly don't know.

If you were to try a bean setup with this you'd likely have to have the pipes on a continuous slope, but that would be a drop of about 5' over a run of 10' - pretty shallow. Try posting your question as a new thread in the DIY section. I think you'll get more people viewing it with more ideas there.

 

[sleepydoc]

So why exactly would my open stand pipe be siphoning and my siphon stand pipe just trickling? It really doesn't make much sense to me.

The open stand pipe shouldn't be siphoning since it has the tube sticking out the top of it, right?

All 3 exits in the sump are under water. Would that be a reason?

I just looked at the pics you posted a while back and I'm confused - you appear to have 2 drains inside the overflow, one turned up and the other turned down, and a 3rd outside the overflow. in addition you have the overflows connected to vinyl tubing that goes through the wall. Where is your sump?

 

[Bent]

I just looked at the pics you posted a while back and I'm confused - you appear to have 2 drains inside the overflow, one turned up and the other turned down, and a 3rd outside the overflow. in addition you have the overflows connected to vinyl tubing that goes through the wall. Where is your sump?

Well the sump is in my basement, so the drain goes through the wall to the basement. Like so:

(Ignore the fact that the drains aren't plumbed in this pic. They go to the 3 elbows on the right.)

The water level sits right above the drains.


Also in the pic I showed you, both of the elbows inside the overflow box are pointed down, I just forgot to turn one in the pic. The elbow outside of the overflow is the emergency pipe. I didn't have enough room in the box to plumb it inside. Didn't figure it would matter much.