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Water pumps in series?

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SledgeMakeGood

New Member
Joined
Aug 21, 2004
Anybody know if there are any advantages to running centrifugal pumps in series? I have no less than six water blocks set up in parallel with manifolds so that every component gets the coolest water possible, but I need more flow to them and I don't want a giant, electricity-sucking, loud pump. I know small pumps have trouble with pressure and keeping flow high at pressure, so would putting two pumps inline be better or worse, for my system and for the pumps themselves?
 
run the pumps in paralell to get more flow.

Line>split>2pumps>unsplit>line

that way tehy pull twice as much water.

Running 2 pumpsi n a series will get more pressure(head) but no more flow
 
That's what he needs though. All those blocks are pressure drops. Add another pump and all of a sudden all those pressure drops aren't that big of a deal anymore. Or you can split it up, one pump for half of your waterblock, the other pump for the other half, use the same radiator and resevoir.
 
/\ What he said. That just doesn't sound right.

Add another pump and all of a sudden all those pressure drops aren't that big of a deal anymore. Or you can split it up, one pump for half of your waterblock, the other pump for the other half, use the same radiator and resevoir.
That's the way to go about it. Either two pumps in series to cope with all the backpressure, or make two seperate loops.
 
Thanks all for the input. I'm going to give it a try and see if the head, flow, or both increase or suffer, but I'm still wondering if it's going to stress either pump or if it will actually reduce the workload of both. That's what I don't think I can find out by experimenting, so if anybody knows anything about fluid dynamics, I'll say thanks in advance for your help.
 
YOu definately want to run your pumps in series, not parallel. Series will give you twice the pressure (assuming you use 2 identical pumps) which will in turn give you more flow. Not sure how you have all your blocks set up in parallel, but I would probably run those in series too. The water only gets heated by a tiny amount, .1C or so after each block so it doesnt get as hot as you might think.
 
SledgeMakeGood said:
Thanks all for the input. I'm going to give it a try and see if the head, flow, or both increase or suffer, but I'm still wondering if it's going to stress either pump or if it will actually reduce the workload of both. That's what I don't think I can find out by experimenting, so if anybody knows anything about fluid dynamics, I'll say thanks in advance for your help.

UGH

disgust only because this has been covered so many times before

in series head will increase and flow in a system with restriction will moderately increase

in parallel head will remain constant, flow will increase slightly, but not nearly as much as in series, because a WC loop is pretty restrictive for a centrifugal pump

it will not stress the pump. max stress occurs just before cavitation, or when the impeller stops spinning
 
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in series head will increase and flow in a system with restriction will moderately increase

in series head will remain constant, flow will increase slightly, but not nearly as much as in series, because a WC loop is pretty restrictive for a centrifugal pump

Need to change Underlined to Parallel.
 
In response to nikhsub1 (and for general information, I guess I should have posted earlier):

I built manifolds out of 3" acrylic cubes to split the water flow evenly among the waterblocks so that the same water wasn't pushing through block after block in a series circuit. The result in practice is an slight overall improvement in flow, even with the increase in total hose length. As for cool water going to each block, you're right, the temperature doesn't increase much from one block to the next when set up in series, but I notice a difference running this way that was enough to allow me to run without radiator fans.

I also did this because I needed an elegant way to connect my water blocks to my much larger diameter return line (connected to an automotive radiator that has 1-1/2" input & 1-3/4" output). I could have run them all in series and made a 1/2"-to-1-1/2" adapter, but having to use the large diameter hose gave me the opportunity to try this out and it works well.
 
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