Building a Weir style Overflow

[JohnO]

[quote author=Matt Rogers link=board=DIY;num=1088694760;start=15#29 date=07/26/04 at 21:06:41]What's the prob John? Are you watching American TV? *
Ben that was a good post. I never paid that much attention to the partition in the box before. Seems to make sense to me.[/quote]

Yeah too much TV is probably the problem :-)

I think I am suffereing from post POST depression or something :-)

I reckon I will just have to go and see one of these things actually working ( without any means of water flow control ) to convince myself it actually will work unsupervised and wont sh*t itself when the power goes off LOL

I certainly hope no one thinks that I am being difficult, it's just that I am inquisitive(sp).

John

[Matt Rogers]

WIsh I had one to send you.
If you were closer I would throw it at you.
j/k

[JohnO]

You don't scare me mate :-) You probably couldn't tear the skin off custard :-)

John ;-)

[Matt Rogers]

Never heard that one before!

[JohnO]

Well, you should pay a little more attention shouldn't you? LOL

Finally got some water in my tank last night, will post some pics soon, in a different thread

John

[Redbeard]

Didn't mean to confuse you, sorry. :huh:

If the drain ( for example ) syphons at a rate of 10gallon per hour and your return pumps at 5 gallons per hour, what will happen?

As long as the flow rate of the pump doesn't exceed the capacity of the drain the water will return to the sump at the same rate as it is pumped into the tank.

Naturally if your pump exceeds your drain capacity you would have to divert some of the flow back to the sump or restrict it. I've heard that gate valves are easier to tweak than ball valves. Don't know, never tried it.

I over-sized the overflow drain on my system to accommodate surges, (my) arms in the tank, debris restricting the drain etc. (Honey, I found Spongbob!).

Ted

[Redbeard]

Oh yeah, I forget to mention that in the case of a power outage, the water in the tank would simply drain back to the sump until it dropped to the low water level set by the skimmer box, just like with a drilled tank. With no water being pumped to the tank there's no water draining back to the sump.

The only way the siphon would break is if there were enough dissolved gas in the water to create an air bubble big enough to break it when it came out of solution. In that case the venturi pump would suck out the air and start the siphon when the power was restored.

[Matt Rogers]

Good point about the gate valve Ted.
And thanks for joining.


(Look forward to pics John!)

[Chris Jones]

John, :-* the overflow will work automatically right up to the capacity limitations that i mentioned above, hence the same amount of water flows out and down as is returned by the pump.
once you exceed the limitation of the GPH of the siphon cavity capacity, or the down-pipe capacity, you will have to increase one or the other, or both.
Other than that you could adjust the return rate of the pump as DX will do with the tee off at the sump. so if your pump will move 900 GPH but the overflow can only handle 750, you would throttle or divert 150-200 GPH with the valve on the output of the return pump, or get a second overflow.
those are your adjustment options.

[JohnO]

Dear Doctor,

That was my point exactly :-) Others were saying that the flow rates would automatically match each other. My statement was that they wouldn't and you would need to be able to control one or the other. DX is doing this by the use of a tee section as you mentioned.

John :-)