Originally posted by bigDJP
... Will the overflow box only allow as much water out as is being pumped in? As long as the overflow box is rated for more GPH than the Pump should I be alright?
That's it basicly...
With a properly sized pump and return line (so you can calculate "head" pressure, and "actual" flow accurately) you shouldn't need or want a ball valve to "cut back" your flow on the pump...
(A ball valve and quick disconnect is nice for "shutting the system down" if you need to remove the pump for maintainence, but it should not be "neccessary" for flow control)
The pump will use the same amps whether it's running wide open or "cut back" by 50%, so "efficiency wise" it's important to get the right pump and line set...(most gallons per watt)
You want the overflow to be rated (able to ) remove "more" water than the pump "actually" puts in to keep the tank from overflowing, but especially on U tube overflows, you don't want it to be "TOO" big or over rated.
If the overflow is too big compared to "actual" flow from the pump, the water will flow too slowly through the U tubes to "pull" air bubbles with it...They can then "build up" over time, restricting and possibly "break" the siphon (causing a flood condition)...
So proper "balancing" is done in the calculating, planing and purchasing stage when setting up a sump system...
