[Gooserider]

Many folks may view me as excessivly paranoid for even starting this thread, but I do see a need for balance in design. Just where the balance is drawn can be debated, but it is easy to stake out the extremes.

On the one side, not taking ANY precautions makes the system an expensive failure waiting to happen. The other extreme is to add so many safety functions that the system becomes overwhelmed and non-functional. It is not unlike the debate in the computer security business between ease of use and security, it is difficult to do both.

My opinion is that it is important to have failure detection, and to design so as to reduce the odds of failure. However good design is more critical than failure detection (it is better NOT to have the failure than it is to detect it!)

Failure detection should be limited to failures that are fairly likely. Shouldn't be expensive, and must not be so complex as to become a possible failure source of their own. Ideally it should provide useful information even when NOT detecting a failure. A thermometer is a good example - it tells how hot the system is normally, but can trigger a shutdown if it goes over range. A leak detector isn't good this way, but it provides a valuable and low cost safety function.

Solarian League is IMNSHO going way into the overkill range, and possibly making some bad design decisions as well.

Solarian League: i'm going to get an water cooling system that probably will have pelts on it

Pelt runners might argue with me, but my reading has led me to the conclusion that UNLESS one is doing really radical OC stuff, they are a BAD idea. They seem to add a multitude of additional failure points, consume great amounts of extra power, etc. Looks to me like avoiding them will in and of itself produce a more reliable system.

for the leaking detector,...place one below each barb joint....now you could place a little funnel below both barb then have the leak sensor in the neck of the funnel.

This would get real complex real fast, especially since alot of small leaks start as 'sprayers' that might not hit your funnel. If I *WAS* to do something like that; I would be more inclined to wrap the plumbing in absorbent cloth of some sort (maybe some of that 'tube bandage' stuff?) that would absorb water and wick it to the low point on each tube. The sensor could then be a couple of bare wires on the side of the tube, which is cleaner.

However this seems overly complex, the water will reach the bottom of the case soon enough, so put a sensor or two there and be done with it. (My server case has two chambers, so I'd need a sensor for each side) If one wanted to get a bit fancier, the pump and the rad seem to be the biggest potential leakers, so put each in a tray and add a sensor to the trays.

...you could optionaly have an additional setup. ... put in a fewlights, ... small say 9 volt battery ... hook the lights up into ur auto kill system ... and one of the light on the little pannel comes on and it will stay on ... so the user will know why the system triped and where the leak was.

It's called a 'First out' system, and I first encountered them back in the late 70's, when they were done with relays that made a very complex and expensive setup. With modern circuitry it would probably be a lot easier / cheaper, but still adds another layer of complexity which isn't really needed - you can SEE a leak, etc. Most of the failure modes we are talking about are pretty obvious with minimal testing.

the total cost should be i hope maybe $50 or less, depending on what you want to do with it i guess. its just an idea, and admitly i like the idea myself, i'm newbie to watercooling and this idea might help me push my watercooling system to.

I think you are WAY underestimating the cost of what you are describing, It looks to me like over $100 just for sensors and indicators...

I'm thinking more in terms of ONE relay, and maybe a 'wall wart' power supply. A $10 flood alarm from Home Depot. The rest of the sensors would be in the system already for other monitoring, and just feed the 'kill relay' as an extra step.
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BladeRunner: I think that maybe you are all going overboard a little.

I don't think I am, but agree that SL is... However it's debateable.

I'll have to do an air pressure test with my clipless pipes but I can assure you they will not pop off, slip off, or leak, Just think about it with the barb in a vice using all my strength and body weight all I can do is stretch the tube a bit.

Ever hear of a 'Chinese Finger Trap'? Pulling on the hose is like trying to get out of one with a straight pull. Water pressure is going to work more in a direction to make the hose slip.

I used to have the whole system with barbs done in a similar fashion, and none ever leaked or came off. I much prefer the festo push fittings now because I can make smaller neater blocks and connect and disconnect them quickly & easily without worry of leaks. The tube isn't an issue once you have some of the correct stuff, I think it was about £15 for 20 meters of the 8mm

As I said, I'm not arguing (much ;-) ) with your methods, just commenting that they aren't to my preference. I'll admit that what you are doing has worked well so far, which is a strong point in it's favor.

The liquid level sensor as said I haven't done yet but I'll be using a sealed optical type liquid sensor I have here atm.

Do you have a reccomended source / brand, or is it just something you happened to find? I'm in the process (in a different window) of getting a nice flow sensor for $10 here http://sales.goldmine-elec.com/Index.asp as I send this message. It's a rotor type, and I'm not sure how easily it can do flow measurement, but it has an adjustable flow failure detection relay and appears to be a nice unit otherwise.

Part of the reason for soldering my blocks is with the more complex shapes of the VGA ram blocks and Splitter-X in my system, it would be very difficult to make a seal grove without access to CNC, and like you say the blocks can be thinner walled and smaller overall if soldered.

Your blocks certainly are beautiful in the pictures, your finishing work is incredible. Aside from looks, is there a reason for such a high polish on the non-contact surfaces? (I agree with lapping the contact surface, but was thinking more in terms of wire wheeling the rest...) I also noticed that you say you pressure test before finishing, but not after. Seems to me like there is a slight but present risk that a leak could be created by disturbing/removing the solder that was covering it before finishing. Is there reasoning for doing it this way, or did you leave something out of your process descriptions?
As to seal grooves, I wasn't planning on them. I was planning to use flat surfaces with a liberal layer of RTV or aviation Form-a-gasket between them, with 6/32 bolts holding things together. I might also use a thin gasket, but didn't think it was really needed.

It doesn't really matter what target you set yourself but I think you have to be realistic when using water cooling and that's why I say "major disaster every two years". I would probably double that to every four years if I just built the system and then didn't dick around with it at all, but as I'm constantly modding it and upgrading parts of it adding new blocks etc, the possibility of a screw up on my part is much higher. It wont change the world but if you beat your target you'll get a nice warm feeling about it too.

Seems reasonable to me. I'd like to get at least 4 years between major failures, but then I'm not planning to mess with the system much once it's built.
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Solarian League you might think it is overkill but heh if its what $50 to say $100 to do a little bit of disaster prevation

The problem is that what you describe is NOT 'failure prevention' but 'failure detection'. It appears to me that you are working to hard on the former, and not enough on the latter.

its well worth it like that funnel and the water sensor with little lightboard on front of computer heh atleast if something goes to hell you will know what it probably was before opening the case

If the 'kill relay' tripped, odds are I'm going to need to open the case anyways. I can wait to find out the bad news until then :shrug: Your proposed 'first out' system appears to me like it would add little value compared to it's cost.
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bigben2k Here's the latest flow switch

Thanks, I'm getting one from the last source mentioned there.
[quote]bigben2k: No, a hose split is not reasonable, neither is a blow off. To make sure it doesn't happen you use hose clamps and forget about it. That's what I meant by "good design". [quote]
Not saying it's LIKELY, but I am saying it's possible. It isn't WC'ing a PC, but I've seen each of those failures in automotive fluid systems. The stresses are lower, but I don't see anything magic in a WC system that makes them impossible. (But I'm planning design to make them less likely!)

What has happened historically, is that a brass barb in an Aluminium top would corrode, and break a seal: just don't do it. Hose split has happened once, when the water was allowed to get so hot, that it melted the tubing, so don't allow that to happen either, that's all. The same heat can melt a plastic top, and cause an o-ring failure: I've seen that twice. They were the result of either a lack of OCP, or OCP failure.

Thanks for the historical record, it is useful. Is this just your experience, or has there been some effort to collect this data from multiple sources? (IOW, how big is the sample?)
I am planning to do all copper and brass, so corrosion shouldn't be an issue, I'm also not planning on O-rings or plastic parts other than PVC pipe and the braided poly reinforced hose. I'm guesstimating that I would set my 'panic shutdown' water temp around 50-75*C, which should be well within safe limits for the plumbing.
I assume that OCP is 'Over Current Protection', correct? Is there a low cost way of ensuring that it works?

Thanks,

Gooserider