Silent and Failsafe Overflow System

[Reefer2727]

Thanks again Jim,

I appreciate the response. It doesn't sound like the smaller plumbing is a good idea. You are right, as you have mentioned before. Most of the people that have issues with the design have modified it. The last thing i want to do is modify it. I just wanted to confirm that it would work with the return pump I choose.

Clear up the pipe size flow for me.

 

[stormrider27]

Can anyone answer the below question?

<a href=showthread.php?s=&postid=14761837#post14761837 target=_blank>Originally posted</a> by stormrider27
Wow what a great read! My hat is off to Bean for his knowledge, patience and most of all for being so unselfish with his time by answering everyone's questions! Now, of course, I also have a question for the group. I want to keep the top center of the back of my tank clear of plumbing so would there be any issues with running two narrow internal weirs on opposite ends of the back wall of the tank and piping the water down to one external overflow box that is roughly 12-15" below the water line?

Thanks,
Mark

 

[sgolden]

thanx to Bean and everyone elsewho have added to this thread...I beg your pardon but I havent time to read the entire thing(but i have been working on it)
I need some help, forgive me if i could not find the clues to my answers..I am running out of time...
I have a 110 tall 48x18x31, i plan on a coast2coast angled wier across the back, this will drain through 2x 1" and 2x 3/4" holes to an external box..i have 1"bulkheads and wonder if it is better to have them vertical at the sanitary T or flat below the T..or if i should use a bigger bulkhead and avoid the constriction of the 1" altogether....all everyones help has been greatly appreciated
thanx,
Shaun

 

[uncleof6]

* See below.... forgot to quote.

 

[uncleof6]

<a href=showthread.php?s=&postid=14786676#post14786676 target=_blank>Originally posted</a> by stormrider27
Can anyone answer the below question?

This type of setup was actually discussed earlier in the first half of the split thread, however it was a slim internal, through holes, directly into an external box containing the "pipe heads," with the water level the same. This works. If you ask me, you are asking for headaches with the setup you describe. The system works as designed, with modifications the results can and do vary, and you do so at your own risk.

Jim

 

[uncleof6]

<a href=showthread.php?s=&postid=14786376#post14786376 target=_blank>Originally posted</a> by Reefer2727
Thanks again Jim,

I appreciate the response. It doesn't sound like the smaller plumbing is a good idea. You are right, as you have mentioned before. Most of the people that have issues with the design have modified it. The last thing i want to do is modify it. I just wanted to confirm that it would work with the return pump I choose.

Clear up the pipe size flow for me.

I have a dart, running with this drain system. Street Ells, bulkheads, S tees, pipe et al, 1.5" 1.5" return @ around 5-5.5' head pressure. This puts the flow @ around 2700 gph. Without hooking up the flow meters,( and I don't think a flow meter would be reliable on the open channel) it would be difficult to say how the flow is divided between the siphon, and the open channel. But the difference is large. So I often use a figure as illustrative only. IIRC with 1" bulkheads, (though the rest was 1.25" ells, and 1.5" pipe external) Bean was able to run a dart full open on his setup (though looking for it this morning, I could not locate it) But as you can see, the numbers are way above what you figured. This is because calculators and the like do not take into consideration full siphon (acceleration due to yitvarg, the length of the drop, and the suction thus created.) With a low flow, you would have a hard time getting the larger pipe size to actually full siphon to begin with, and sustain it long enough to dial it back the correct amount. (but rethinking this I figure you can start/stop the system and close the valve a bit more each time and get it close enough to be able to dial it in) What i have described elsewhere as "under pumping." Downsizing the full siphon and emergency would help with this, but then limits the expandability of the system when you discover that there really are advantages to higher flows (out of the range and topic of this discussion.) What is the full siphon flow of a 1" pipe? Well that is what I went looking for and also could not find, but according to the above info, and without knowing the velocity would be hard to calculate, I would say near 1000gph, but what the saturation limit is for either, I don't know. (the limit where you just cannot get more water through it regardless) However, using recommended max velocities (for ~0 noise) a figure can be determined in that respect. For pvc, that is 10ft/sec. Flow in gpm = 2.448 x velocity x diameter squared. So with 1" pipe you would come up with 1468.8 gph, and for 1.5" you would come up with 3304.8gph To come up with the actual velocity, one of several implicit equations must be used, and to account for the elevation change a second equation is required. Please do not make me do that math.

Regards,

Jim

 

[uncleof6]

<a href=showthread.php?s=&postid=14786970#post14786970 target=_blank>Originally posted</a> by sgolden
thanx to Bean and everyone elsewho have added to this thread...I beg your pardon but I havent time to read the entire thing(but i have been working on it)
I need some help, forgive me if i could not find the clues to my answers..I am running out of time...
I have a 110 tall 48x18x31, i plan on a coast2coast angled wier across the back, this will drain through 2x 1" and 2x 3/4" holes to an external box..i have 1"bulkheads and wonder if it is better to have them vertical at the sanitary T or flat below the T..or if i should use a bigger bulkhead and avoid the constriction of the 1" altogether....all everyones help has been greatly appreciated
thanx,
Shaun

I don't get the angled weir thing, but this is not the first time I have heard that and made no comment the first time.. so:

I understand what you are contemplating. As I said above this was discussed early on. The internal to external is a sound idea, for saving real estate inside the tank. I think you are restricting the flow between the two with 1" and 3/4" holes, and the more seamless this connection, the fewer balance problems you will be faced with. As for the plumbing in the external box: Plumb it the same as any other drain setup. I.E. Bulkheads in the bottom of the box, and "heads" in the box. I would say it is better to plan ahead for the time when you discover that the low flow may not quite be accomplishing what you wish it to. And at the very least, keep the open channel "large" for reasons quoted above.

Regards,

Jim

 

[teesquare]

Uncle of6:
Thanks for coming to the rescue to answer some of reefer2727s questions. I have read and re-read, and installed a few of these - but my memory ain't what I wish..... And they say it is the second thing to go...just can't remember the first one.

Reefer2727: What he said <G>!!!!
Really, Unc has expressed eloquently what you need to know to be successful. But also understand that as long as you start with large enough hole size - you can always bush it down. You cannot go the other way.
And - hey- don't be too afraid of experimenting a litlle, after all.... How do you think this method got invented?

 

[sgolden]

thanx jim, the only reason for the 3/4 holes is they already exist
( i have 4 holes across the top back) that will just flow to the external box...i wondered if the reduction to a 1" played a part in the acoustics of the hydrodynamics....I imagine that the siphon of a totally 1.5" drain would be powerful/ hence noisy...thanx again

 

[teesquare]

Size of pipe does not equal noise............................
T

 

[uncleof6]

<a href=showthread.php?s=&postid=14787922#post14787922 target=_blank>Originally posted</a> by sgolden
thanx jim, the only reason for the 3/4 holes is they already exist
( i have 4 holes across the top back) that will just flow to the external box...i wondered if the reduction to a 1" played a part in the acoustics of the hydrodynamics....I imagine that the siphon of a totally 1.5" drain would be powerful/ hence noisy...thanx again

Actually the noise level of a 1.5" drain at full siphon, and a 1" at full siphon is the same: None. Where size does make a difference (ok I don't want to hear it) is with the open channel, the smaller the pipe the more noise the open channel will make, at a given flow rate. Has to do with the air/water ratio, and velocity. The more air, (larger pipe), and the lower the velocity (larger pipe) the quieter. which is why it is hard to silence a strictly durso/stockman type systems. The flow rate has to be what it has to be. In this design, the open channel (aka durso type) is slowed down to the point that the flow is laminar (sheet of water with air in the middle) so it is quiet, with no bubbles. The only real solution to the problem with dursos.

On the holes out the back: The solution is obvious, make them bigger, within the limits of what is safe as far as distance apart and glass edges. Nothing says they cannot be turned into slots either. (The how-to is not within the scope of this discussion).

Regards,

Jim

 

[uncleof6]

<a href=showthread.php?s=&postid=14787658#post14787658 target=_blank>Originally posted</a> by teesquare
Uncle of6:
Thanks for coming to the rescue to answer some of reefer2727s questions. I have read and re-read, and installed a few of these - but my memory ain't what I wish..... And they say it is the second thing to go...just can't remember the first one.

Reefer2727: What he said <G>!!!!
Really, Unc has expressed eloquently what you need to know to be successful. But also understand that as long as you start with large enough hole size - you can always bush it down. You cannot go the other way.
And - hey- don't be too afraid of experimenting a litlle, after all.... How do you think this method got invented?

I am a senior citizen, and my memory is shot out too, and it was the second thing to go. But I doubt you need me to pm you about what the first thing was: I will probably forget that I am posting in the thread.............

J

 

[teesquare]

My wife occasionally "points out" (pun intended) the "first thing" to go.......
Salient, response to sgolden. Exact, and well put!
T

 

[uncleof6]

<a href=showthread.php?s=&postid=14788412#post14788412 target=_blank>Originally posted</a> by teesquare
My wife occasionally "points out" (pun intended) the "first thing" to go.......
Salient, response to sgolden. Exact, and well put!
T

I am single so...... chuckles anyway on with the show.

Salient? I am not so sure, but then salience is easy when you HAVE to use crib sheets.:lol:

Regards,

Jim

 

[teesquare]

Crib sheets?.... I am a Depends man myself, HA!
T

 

[uncleof6]

this is goin downhill quick.......:smokin: you might possibly appreciate an email I went looking for last night when a similar situation came up.......

Jim

 

[teesquare]

Send it on!
I will pm you my e-maill address
T

 

[sgolden]

thanks again for the input...i actually have holes for 1" and 3/4" bulkheads...so the actual holes are 1.75 x2 and 1.25 x2...so I should be able to flow plenty of water into the external box... thanx for all the help guys...what would you guess its maximum "quiet" flow would be near?

 

[teesquare]

Will the waer level in the tank completely submerge the diameter of the holes?
T

 

[uncleof6]

<a href=showthread.php?s=&postid=14788754#post14788754 target=_blank>Originally posted</a> by sgolden
thanks again for the input...i actually have holes for 1" and 3/4" bulkheads...so the actual holes are 1.75 x2 and 1.25 x2...so I should be able to flow plenty of water into the external box... thanx for all the help guys...what would you guess its maximum "quiet" flow would be near?

If you have been following the ensuing conversation it is easy to see how overlooking that could happen :lol: I would think that would be ok, but until things are glued as it were (silicone is not glue) you can experiment with the holes you have-- and if it does not flow well, the holes can be dealt with. The holes should be below the water level of the tank....

as for your question... not easy to answer and depends on the pipe size, but at your flow rate, you will have trouble knowing it is actually running once it kicks in.

Jim