Which would give the best flow rate?

[isa.alhadad]

Thanks guys for the much appreciated feedback. I now know a little more about overflows.

 

[Jgray152]

Isn't that what I said? The height won't make a difference, just the end point.

I don't believe so, unless I misunderstood your post. The height from water level point on the down flow side, to the "T" actually makes a difference if you were trying to get flow flow out of the pipes since the higher the water in the pipe, the more pressure is created at the bottom.

 

[Lil_Stinker]

I don't believe so, unless I misunderstood your post. The height from water level point on the down flow side, to the "T" actually makes a difference if you were trying to get flow flow out of the pipes since the higher the water in the pipe, the more pressure is created at the bottom.

If the T is at 1/2 dept or at the bottom edge of the tank, it won't matter either way ... IF ... there is a closed tube coming off it to the same exit point (i.e. top of sump)

 

[Burko]

I cant see why a longer/higher overflow would help.

As I understand it...

The pressure is governed by the hieght of the inflow (tank level) and the depth of the outflow.

The speed of the flow is limited by the capacity of the pipe and its terminal velocity, for water.

If the pumps ability is greater than the overflow...increase the diameter.