Pumps Question...

[Morisimo]

After posting a question a few days ago about Positive Displacement Pumps, as mentioned by RhoXS in the Flowrate 'Sticky', I am still no wiser as to whether PD pumps are better than centrifugal pumps for use in a water cooling setup.

I am new to this forum and I am just wanting some friendly advice, please!!!! I know there are people out there who have the answeres... So. Here was my question:

What are the advantages/disadvantages of Positive Displacement Pumps over Centrifugal Pumps in a water cooling setup?

I found the following example of a PD pump and the following:

http://www.williamsonpumps.co.uk/400/400spec.html

Is it any good or are there any others like it that are better etc.

This can also be found on:

http://www.ankoproducts.com/peristaltic_pumps.html

I await the (possible) replies!

[Morisimo]

I guess nobody wants to reply... I only want some advice! Some of you guys must know something...?

[seeker]

pumps question.....

I'm sure no expert but those pumps are really overkill for water cooling. They are specialty pumps for high lift/high pressure apps and precision flow delivery.
I would guess at higher flow rates they would cause vibration (pulsing) in the system also.
Probly overkill on the wallet too!
Give it a try though if you want and let us know. Good luck with it :)

[Morisimo]

Thanks for replying Seeker!

Now knowing that these kind of pumps are quite specialist, I understand why I didn't get many replies! Anyway...

I was wondering... Will an increased flow resistance affect the flowrate of a PD pump as much as it would a centrifugal pump, as I know that centrifugal pumps suffer greatly from higher flow resistances... The pump that I mentioned above (the first link) is rated at 80GPH with 1/2" tubing. Could it maintain this in a water cooling system?

Also, how much effect will this 'pulsing' have and is it good/bad for the system in the long term? How much noise do they make and how much are they?

So many questions!?

Thanks again for replying Seeker... At least I now have one reply!

[seeker]

as for the flow resistance, I think there would be a lesser effect for the pd pump, BUT........I think it would increase the pulsing effect. The output of pumps I have seen of this type look like a squirt gun. Severe pulsing.....If you see one work you would understand. If that was my only choice for a pump I would never use it, period. (imho) :)

[MajinSSJVegetto]

You could ( think) put two of them off sync so that during ones off point, the other is on. It should fairly balance the pulsing, but since the "waves" of differing pressure aren't basic sin waves, but very irradic, it would probably be closer to simply doubling the frequency of the pulsing.

The other way to solve the pulsing is to make the pulse be pushed into a chamber with a very small outlet the controls the flow rate. This stops the higher pressure from entering the tubing to fast, and lets it slowly enter over the time before the next pulse comes.

I don't think these solutions are very easy to implement, especially for this kinda of system, but they are what I have done in the past on other projects (mainly with air pressure though).

Just go with centrifugal. I doubt you want the possxibility of tubing busting or coming lose and dousing your mobo.

[seeker]

[Q
Yea, what he said (MajinSSJVegetto)
;) Those pumps would seriously stress the seals in any system........Just say no :)



forums....so....slow.....Scotty.....engage...,hype rtext

[Morisimo]

Thanks for all the advice guys! I'll steer clear of this idea...