Pump and Plumbing Question

[LPorc]

Greetings all...

Background:

I've been lurking and doing a lot of Googling planning a setup. One thing I've noticed is the typical selection of pumps tends to not leave much room for decorative plumbing or 20 m loops . Looking at the P/Q curves I see why everyone is counting bends and going for short tubes, to get the most out of the pump you have to, it's truly an art - most of the pumps will drop below my target 6 lpm flow rate on a short loop with just one restrictive CPU block!

Ok, that aside, on to the question: can I be more decorative (or even just sloppy ) with my plumbing if I am willing to shell out the clams for a closed impellor (high head) Iwaki-Walchem pump that will still push 6 lpm through 6+ m headloss?

I've seen the arguments about added pump heat, but this is a magnet drive pump estimated to only add about 35W heat to the loop, and I have the heat exchanger capacity to handle that . I've also seen the arguments about increased pressure and leaks or popped fittings, but the max psi we're talking about is still very reasonable, and I believe in clamps and sweated fittings. As for the size of the pump (darn near a foot long ), I am not concerned there, I have plenty of room .

Are there any other reasons not to get such a pump? :shrug:

[gruntledweasel]

Can't speak for owning one of the nicer Iwakis (wish I could! ), but the impression I've gotten is that with those pumps, you get what you pay for.

Just out of curiosity, what are the details of that loop? Perhaps you could achieve your target flowrate by moving to larger ID tubing?

[MMZ_TimeLord]

Also are you talking 6+m of headloss because you are running a waterfall? :shrug:

A closed loop will NOT loose as much head ... gravity will assist one half of the loop.

[LPorc]

Originally Posted by gruntledweasel

Just out of curiosity, what are the details of that loop? Perhaps you could achieve your target flowrate by moving to larger ID tubing?

The details are still coming together, but some pieces are ordered already. The loop will be all 1/2" ID or greater, except where it will be tube-in-tube, and even there the cross-sectional area of the flow path will be at least as large, but more friction loss due to more surface.

I've never understood the fascination people have with lights and windows on their case, perhaps because I've tinkered with computers for so long. I decided that for me to show it off, it has to be something designed to be shown as well as functional. And case mods like the Y2K bug and the like don't count, they're a bit too cutsy for my taste and don't accomodate a high-end rig or three.

So I am getting a bit artsy with a custom enclosure and some ideas that are practical, functional, fun, and good looking, while essentially being a piece of furniture and the last enclosure I'll ever need. The pump and res will be internal, the custom heat exchanger will be external.

I am approaching this all kind of like I would building a model railroad setup, I've got a goal in mind, but things will meander a bit on the way, and it's a project that will be ongoing.

[LPorc]

Originally Posted by MMZ_TimeLord

Also are you talking 6+m of headloss because you are running a waterfall? :shrug:

A closed loop will NOT loose as much head ... gravity will assist one half of the loop.

I just tossed out the 6m/6lpm figure as a point on the P/Q curve of the Iwaki I am considering. This all started when comparing flow vs head loss for blocks and head vs flow for pumps. It just seems with the little pumps I'd end up having to either use them in series for more head to achieve my flow target, or in parallel for multiple loops.

Keep in mind I estimate 20 m of loop, and want some decorative plumbing.

[pauldenton]

Originally Posted by LPorc

I just tossed out the 6m/6lpm figure as a point on the P/Q curve of the Iwaki I am considering. This all started when comparing flow vs head loss for blocks and head vs flow for pumps. It just seems with the little pumps I'd end up having to either use them in series for more head to achieve my flow target, or in parallel for multiple loops.

Keep in mind I estimate 20 m of loop, and want some decorative plumbing.

a laing/dangerden D4 at 16V will do 6ipm at 6M according to Cathar's testing i believe

[pHaestus]

will likely be pretty noisy at 16V too

[|kbn|]

Sorry for going o/t got a few questiosn realting to this...

Ive ordered a D4, should arrive tomorrow to replace my 1250. What part acctually gets niosy in the D4? Im hoping it just cavatates at 16v (sp?) becuase of lack of water at suction side. If its the motor/bearings then ill be forced to run it at 12v
Btw d4 pumps are rated for 24v aint they?
Also If I had a heatercore outside, thats about 6m down+ 6m up + all the stuff blocks etc atm, would that be bad for flow?

[Turbokeu]

Originally Posted by |kbn|

Btw d4 pumps are rated for 24v aint they?

Nope...
Laing DC pumps are rated for 12VDC continuously, but will not burn out till 24V...(min-max=4-24V)

Although they do exist in 24VDC version (min-max=12-30VDC).

CD

[jlrii]

Originally Posted by |kbn|

Sorry for going o/t got a few questiosn realting to this...

Ive ordered a D4, should arrive tomorrow to replace my 1250. What part acctually gets niosy in the D4? Im hoping it just cavatates at 16v (sp?) becuase of lack of water at suction side. If its the motor/bearings then ill be forced to run it at 12v
Btw d4 pumps are rated for 24v aint they?
Also If I had a heatercore outside, thats about 6m down+ 6m up + all the stuff blocks etc atm, would that be bad for flow?

The noise according to Cathar is genarated becase the pump uses square wav DC to drive it

The noise would most likely be from the flipping magnetic fields of the brushless micro-controller introducing small vibrations. The Laing engineer said that a square-wave generator pattern is used to flip the fields, and indeed if you've ever listened to a square wave through a speaker, there is a striking similarity to the tone of the noise heard that the pump makes.

[|kbn|]

not what I was hoping to hear ill have to use 12v

[nexxo]

--or you could use a Davies-Craig EBP. Apparently they perform not bad and are not as noisy.