[Gooserider]

BladeRunner: I've got a little involved in this and although it's not finished the way I want it yet, as I've a liquid level detector to fit to the res, and water detectors to the base of the PC case, I have a very simple low restriction flow sensor / shutdown system that also wont allow the PC to be started unless the pump is plugged in and on. more on that HERE

Nice article, similiar to what I'm planning on the PSU setup though I'll probably do the wiring a bit differently. I plan to have a relay that will kill the power to the PSU and pump if a problem is detected (If I have a leak I want to get the pressure off the system and keep the leak minimized if possible)

I didn't see anything about the level detector, though I think that should be pretty easy, at least for a 'low level alarm. I plan to put a sight tube on the res. to make visually checking the actual level pretty easy. If I put a float in the sight tube with a magnet in it, I can do proximity switches to get a rough quantity reading. Alternatively, I might be able to do something with adapting an automotive gas gauge... BTW, do you happen to know of a US source for those flow sensor switches?

The key to lack of leaks is really in the hands of the, individual, the design and application. I like the festo style push fittings for all the other system blocks than CPU in my system, (the CPU benefits from a bore size that makes push fit types unsuitable). The fittings are rated 10 bar air and so far I've had no leak issues with them. They are also simple to disconnect reconnect when messing about with the system. With the CPU block using standard barbs I always use one larger than the tube, (barb ID same as Tube ID tygon r-3603 on 5/8 barbs for instance), so the tube requires boiling water immersion and a lot of effort to get it on. Once on no ugly, and possible leak causing hose clips are not required, as the tube will not pull off even using all my weight and strength with the barb in a vice.

I'm not crazy about those type of fitting, I don't like something that makes such a critical issue of what sort of hose is used with them. I prefer barbs. Maybe I'm over conservative, but I tend to use a barb size that matches the hose, and either worm clamps or tie-wraps. Clamps only cause leaks when the're improperly tightened.

I won't argue with your results, but I really would use at least a tie-wrap on your barbs, no matter how tight they seem. I have seen pressure cause a hose to stretch just a little bit as it ages, and either start seeping or blow off the fitting. A clamp (or tie wrap) puts a limit on how far up the fitting the hose can stretch.

As far as blocks go I solder them together, and make sure to air pressure test them with 4 bar air, the block immersed in water. The block is place under an upturned glass bowl underwater with all air removed and left overnight if there is even the slightest air leak it will show as trapped air in the upturned glass bowl.

I've been debating with myself about whether to solder or screw my blocks together. Soldering seems more reliable, and would allow a thinner wall section, but also means not being able to get inside the block to service it. OTOH, screwing onto a layer of permatex should give a tight seal, after all it's how they put bike engines together and they (mostly) don't leak

I'm not arrogant enough to believe I will never have a leak or disaster but the risks can be significantly reduced with some care and forethought, the most important thing is logical working procedures, when putting it all together. I have an acceptable situation in my mind, and that is one major water-cooling disaster every two years, to me is acceptable to have silent Water Cooling over noisy air-cooling........... so far 1 & a half years on...... (crossed fingers), no leaks or death by water-cooling et

Seems reasonable to me, though I hope to make the disaster as minimal as I can.

bigben2k: You really can't do anything about the HSF/WB popping off the CPU: just keep it bolted. That's a design requirement.

I can't bolt it, the mobo I'm using doesn't have the bolt holes, so I have to do a clipon. What I'm thinking is that my case has a mobo tray with a cross peice already to hold the boards in place. If I extend that arm to the CPU area, I can put in some supports to take the plumbing weight and possibly put an arm with a spring on it onto the block to give it some extra support.

Some flow meters add a lot of resistance, but flow sensors usually don't, if properly selected. I can't believe that you didn't find the one that was presented recently.

If I saw that one, I must have missed it, or assumed it was a non-US available product. As I asked BR above, can you point me at a US source?

BTW, you're off your rocker about the restriction adding heat: while the heat will appear at the restriction, removing the restriction will only cause the heat to appear at another restriction(s) within the loop Just forget about the heat thing.

I think you mis-read what I said. I wasn't suggesting that a flow restriction would ADD heat! What I was saying was that if a major flow restriction or stoppage FAILURE occurred in a running system, then heat would go up in the CPU's and blocks. A temperature sensor located on or under one of the blocks would see this increase, and be able to trigger a relay to kill power or take other corrective action.

The flow sensor will protect your CPU, even if there is little flow: that's all you need. When there's no flow, then the CPU will eventually, over a certain period of time, overheat and die. The level sensor is a good idea, as long as none of the coolant is evaporating. Even better is the Conformal coating, and an allowance for the leaked water to exit the case. The real problem, is figuring out the possible leak points.

I figure where water is, there is potential for leaks so assume that any hose could split, any barb could blow off, or any block could fail. Try to design around it. The case drain is easy, got a drill? The rest takes a bit more thought.

Gooserider