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Question about multiple pumps in a loop

bjcsoln

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So, right now I got a single pump inline with my system, and originally I was going to replace it with a dual pump (but not enough space). So now, after I cleaned up some of my tubing, I turned on my rig and for some reason the pump (that was working fine) did not turn on. Luckily I was paying attention to the flow meter, and then after several reboots it turned on.

Anyway, what I really wanted to know is the folloiwing:

Can I have a 2 different pumps in series, and if one fails, will the second pump still be able to drive water through the failed pump (assuming that the failed pump didn't seize up and just decided to crap out because it was lazy)?
 

bjcsoln

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Thanks - and another question now that I think about it - would the addition of an extra pump increase the internal water pressure, which could potentially expose a small leak, or do you think it might just increase the overall flow rate. Either way, when I test this out, I will turn off the power on the main rig so if it does leak I can fix it
 

clshades

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Thanks - and another question now that I think about it - would the addition of an extra pump increase the internal water pressure, which could potentially expose a small leak, or do you think it might just increase the overall flow rate. Either way, when I test this out, I will turn off the power on the main rig so if it does leak I can fix it

Series pumps creates head pressure.
Side by side (parallel) creates volume. You'd have wye's on either side of the pumps going in and out of a single tube.

So if a pump had a head pressure of 20 feet, series would create 40. (Layman's terms)

If you wanted redundancy you'd need a bunch of controls and sensors to make that happen. Obviously we don't have room for that. If the PC water cooling industry would create a simple control for this situation they'd definately be more profitable.
 

Izerous

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I might be one of the only people on here actually running dual pumps because realistically even with my crazily sized loop a single pump is still more than sufficient.

as clshades mentioned:
-series = head pressure
-parallel = flow.

However series doesn't need a bunch of control stuff to be somewhat redundant as it will just push through the other pump with a loss in head pressure, when bleeding my loop i'll even only power a single pump just to make it a bit easier.

Parallel NEEDS check valves for redundancy. Without the check values a single pump failure actually means a complete loop failure. Fluid like electricity takes the path of least resistance... a complete loop with water blocks vs the slight resistance of pushing fluid backwards through a failed pump it will flow backwards through the failed pump. And all the fancy control stuff wouldn't prevent this the check valves are a must and well good luck finding such a rare thing as they don't really exist in any quantity for the PC cooling space. You're better off with a single pump than parallel without check valves if reliability is your concern.

Edit:
One of the best things you can realistically do is a shutdown procedure if the pump tachometer comes in at zero.
 

clshades

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Location
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I might be one of the only people on here actually running dual pumps because realistically even with my crazily sized loop a single pump is still more than sufficient.

as clshades mentioned:
-series = head pressure
-parallel = flow.

However series doesn't need a bunch of control stuff to be somewhat redundant as it will just push through the other pump with a loss in head pressure, when bleeding my loop i'll even only power a single pump just to make it a bit easier.

Parallel NEEDS check valves for redundancy. Without the check values a single pump failure actually means a complete loop failure. Fluid like electricity takes the path of least resistance... a complete loop with water blocks vs the slight resistance of pushing fluid backwards through a failed pump it will flow backwards through the failed pump. And all the fancy control stuff wouldn't prevent this the check valves are a must and well good luck finding such a rare thing as they don't really exist in any quantity for the PC cooling space. You're better off with a single pump than parallel without check valves if reliability is your concern.

Edit:
One of the best things you can realistically do is a shutdown procedure if the pump tachometer comes in at zero.
We call this a short circuit in plumbing. The working pump would loop back through the failed pump. Total failure with out check valves.
 

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