How much Pressure is too much?

[Fuzion]

I just got my W/C setup in the case and working after a 72HR leak-down test. Now...I've been told that having too large a pump could hurt your system worse than not enough, is this true?

Here's why I'm asking...I have a D-Tek Kit w/ the Ehiem 1250 upgrade and WW block for now, could i possibly be running too much pressure thru the system with this pump? In less than a month I'm gonna be adding a GPU and NB block, will i be okay until then?

I wanted a pump that would handle most of my planned future upgrades, but now I wonder if I haven't messed up by ordering this pump.

BTW: I'm seeing load temps no higher than 43C, I'm happy with it. I just don't wanna mess it up.

[Ven0m]

Basically pumps with really extreme pressure could be dangerous if parts cna't handle it or tubing is poorly mounted.

You seem to be careful with water - 72h test is really lot of time.

Anyway my definition for extreme pressure for WC rig is let's say 10m+ (30ft and more)

[Fuzion]

cool, and thanks. Some people I'm over pre-cautious. I just like to be safe when it comes to my baby!!

[NeoMoses]

You're in no danger of overpressurizing a system with an eheim 1250. maybe if you were generating over 40 psi you might start to worry about leaking @ the hose barb/tubing interface. That's what hose clamps are for. I believe my 1/8" wall PVC tubing is rated @ 75 psi. Most brass hose barbs are rated in the hundreds of psi... basically, don't worry about it. You're so over-protected, it's not funny.

[Ven0m]

Like puttin on 5 condons :)
sry, I just had to write it :D

[Suma]

hehe
(reminds me last summer :p)

[nikhsub1]

The 1250 puts out a max head (pressure) of 2M. Very average in terms of WC'ing pumps. Once you get to say a 15M max head, that is when you would need to be concerned about too much pressure. And BTW, the first thing to blow with too much pressure would most likely be the rad.

[Fuzion]

Thanks guys. The over pre-cautious jokes aren't funny, I can't help it.

BTW: Don't worry, I only wear one :D

[I.M.O.G.]

The rad? I wouldn't have guessed that... I would have thought the tubing would be first to go... But I guess if you had hose clamps on some metal barbs then the tubing could be pretty strong.

Do rads have pressure ratings? :rolleyes:

I just found this interesting.

[Cathar]

Well, from my discussions with a radiator dealer some time ago. Heater-core radiators are typically rated to around 20PSI for safe operation, meaning that they should not leak. Between 20-40PSI there will be a steady increase in chance that your unit may burst and leak, and above 40PSI you're living on borrowed time if your unit doesn't fail immediately.

Now remember that 20PSI is the problem point. Since almost all waterblocks are more restrictive than a heater-core, one can avoid the issue somewhat by putting the heater-core last in the loop before the return to the reservoir.

Still, extremely few pumps that are suitable for computer water-cooling use will supply anything like 20PSI, let alone 40PSI or even 100PSI. The IWaki MD-70RZ will supply up to around 30PSI. Unless you're using a diaphragm or gear pump (very expensive items) and attempt to dead-head it, you're generally safe.

As a rough rule of thumb, take whatever the max head height of a pump is in meters, and multiply that by 1.4, and that's the amount of PSI pumping pressure that it will provide if you block off the outlet. If the water is actually flowing, the pumping pressure will be somewhat less than this peak value.

[nikhsub1]

Cathar some of your PSI #'s are off. The 70RZT puts out 42 PSI :eek: And even your 30RZT does 24.2 PSI. You better check your rads :D

http://www.netbetty.com/H20/iwaki/iwakipressure.gif

[Cathar]

50Hz vs 60Hz power. My MD-70RZ figures were correct for 50Hz power.

Something very peculiar about that graph too.

The 30RZT is rated for 36' as per that graph, which is about 11mH2O, or around 16PSI.

I'm not sure how they're getting the 24PSI figure.

[Ven0m]

Dynamic pressure maybe?

[bigben2k]

Gotta concur on the rad being first to go: they're often tested to 25 psi, before they leave for the store.

I've seen o-ring specs, and if done properly, they'll withstand 70 psi (each block will be different).

The rad will see 20-25 psi way before a block will see 70 psi.

We're still nowhere near that pressure, with any of the common water cooling pumps: heck, we're not even in the ballpark!

Either way, here's a handy pressure converter:
www.convert-me.com
( go down to "Pressure")