Does 2 pumps running in series help?

I have this question because im thinking of doing this. But im not sure if it will actully do anything.
the setup:
Res-->"y"-> 2 pumps->"y"->rad->blocks->res.

That would be in parallel, not in series. And if I remember correctly, all running in parallel for pumps does is increase flow, not head. Series increases head.

Edit: Thank you crimedog. Additionally:
http://www.ocforums.com/showthread.php?t=229444&highlight=pump+series+parallel+head

I always thought it was the otherway around as in parallel = more head and series = more flow. I could be wrong however.

Jot is correct. Yes, running more than one pump does help but it's usually not worth it to most people.

I stand corrected and it makes perfect sense too

i think the laing ddc or swifty 350 would be great in parallel since they have head not flow

Actually...

Oh, you would have to ask this right after passing my Florida state pump operator, including hydraulics test.

Actually, whether it's parallel or series would depend upon how you arrange the two pumps. If pump A is followed by pump B, but in the same line; you are correct, it is in fact a series and is designed to improve pressure. If, on the other hand, pumps A and B run beside each other with a splitter feeding each on the intake side and these two line rejoining after the two pumps; then would JoT be correct and the system be described as parallel. And, parallel systems are used to improve volume.

Good luck!

thanks for the insight...
lov this forum stuff.