pump plumbing idea

[olivier]

Hi,
i'm designing a plumbing for my future sequence pump to drain beckett skimmer and tank return
this is what i draw :


1 -> 1" drain to skimmer (beckett 8" reaction, 30" high)
2 -> 1" return to tank (approx 100g, sump 10g)
3 -> 2" return to the pump intake

what do you think of it ?
specially the 3rd drain, that i put to allow setup of global water flow, because i want to avoid return to the sump

thanks

[Bruddah Chrispy]

I guess I don't understand #3. Is it some kind of closed loop that never goes through the tank?

[olivier]

yes exactly, i put it here to limit the excess water flow of the pump, or to let me close for example the skimmer's gate for cleaning it without stopping the pump
i'd like to know if there could be something wrong with that config and the pump...

thanks

[BeanAnimal]

Plumbing the loop back to the sump would be a better idea.

1.) the pumps intake is not directly "SUCKING" from the output. This could actually cause cavitation.

2.) because of the pressures involved, you will have less control over the fine adjustment of the "loop" Minute changes in head pressure or valve postion will cause LARGE changes in actuall flow through the loop... as a result drastic changes in output to the display tanke.

3.) water run through a pump in a "loop" tends to heat up MUCH faster, putting it back in the sump creates more surface area to disipate the heat build up.

Bean

[Surf]

I think Bean has the right idea, send that excess back to the sump. I don't think you'll need this to be a 2" line though, really depends on skimmer and tank requirements but I think 2" would be overkill for the loop line.

[olivier]

well ok, thanks for your advices, i will return it to the sump
i was not wishing sending it to the sump because it is a small sump (10g), but i will try to make baffles to limit the torrent
by using a 2" drain, i was sure to get all the flow from the pump without creating back pressure or head loss charges...