Pressure Built Up In Water Loop

[Jdieter91]

So I've searched high and low regarding chemical reactions, side effects from galvanic corrosion and so on and so forth but have found nothing regarding what could cause my system to build up enough pressure to literally blow a fitting/line off.
Admittedly I made a terrible mistake and mixed metals when I did the build, I'm currently waiting for my Phobeya G-Changer 560 rad to come in to replace the thermaltake pacific which I failed to properly research at the time.
The system is in a Thermaltake tower 900
Thermaltake pacific res/d5 combo
Thermaltake pacific 16mm rigid tubing
Alpha Cool 90° in line Fittings
EK HDC compression fittings
XSPC 90° rotary fittings 16mm
EK Supremacy Evo Block (Nickel/Acetal)
Bitspower Hybrid Mobo Block (Copper).

This is the second time the system has done this within 6 months of being built. The first time I pegged it on faulty alpha cool compressions due to me having 8 of them, and half of them had different sized orings then the others. So I replaced them all with EK HDC fittings. When it happened the first time it was off the CPU block and water went everywhere. Thankfully I was close by and was able to pull the power plug immediately. The tower was completely disassembled, everything recleaned a million times, water blocks taken apart for safety etc etc.This time however was very very different.
The PC has not been run in two days, this morning at around 3ish I awoke to an audible pop sound and water splash. I dont have fish tanks anymore so I knew what it was. But, the PC wasn't on or running, just sitting there. This time in blew off one of the 90° in line alpha cool fittings going into the mobo block, its about 5 inches away from the board, inline. The pressure was enough to shoot the water out from the front of my computer and onto my floor.
I've built multiple water cooled PCs and never had issues like this. Admittedly this is my first stupidity of mixing metals but nothing anywhere shows or says galvanic corrosion causes water expansion.
The fluid atm is just distilled water with biocide.
Also the only other possible thing I can think of is silicone. I use, as with all systems I build, a very minute amount of silicone on the outside of the rigid tubing before its slipped into the fitting and compressed. I did this the first time I built this and when I had the first blow out I suspected that I had somehow overdone it and silicone was inline. None was, and there wasn't any overlap if you will of silicone even making contact with water flow.
Also water route goes up from pump, across, up and then into mobo block, down from mobo into CPU, then CPU out, down, then inwards into back compartment and down into radiator. From radiator up, across, then out to res.
Room ambient temp is from 65-70°f with relative humidity around 45-50%
I have another rig, a Half X with an XSPC kit and rigid black tubing that runs almost 24/7 as a media rig hooked to my TV. Its been fine for years.

What am I missing, what did I mess up for this system to be building this much pressure, is it the galvanic corrosion with some type of chemical reaction ontop of it all? Is it the fluctuating in cold room temps(couldn't find any articles about relative expansion at these temps).

As I said my new radiator should be in the next few days, but since this happened a second time, and there's no way its a faulty fitting, and there is nothing I've seen on any forum regarding a system building up this much pressure, I'm baffled

Regards,
Jon.

 

[n0ns3ns3]

the reasons for the tubes popup from the fittings could be:
1. missmatch between tubes and fittings - be sure both are made and advertised in same units (metric or imperial).
2. a bit too much pressure can be caused by very high liquid temperature.
3. a pump running too fast - usually the pressure will build up at first flow restriction - CPU blocks are restrictive.
the 2 and 3 are not supposed to happen if the 1 is properly done. like the fittings should be capable of holding couple of bars - way more than what should be in a loop.
what you can do:
* do not apply lubricates of any kind on orings - just use water (rebuild your loop)
* slow down the pump - for your loop, even 3000RPM is way too much.
may be changing tubes as not all of them made with required precision - kinda cheap to replace.

 

[marko55]

The only two things I can imagine would cause this are:

1) A blockage that's causing pressure build up behind it and causing the blow. Thing is, I'm not sure that a pump could even build enough pressure behind that to actually pop it like this.

2) Some kind of chemical reaction that's causing build up.

Changes in temps, no matter how frequent, wouldn't do this. Changes in temps are what cooling is all about and is completely normal.

Beyond that, I'm not sure what to really offer.

 

[Jdieter91]

the reasons for the tubes popup from the fittings could be:
1. missmatch between tubes and fittings - be sure both are made and advertised in same units (metric or imperial).
2. a bit too much pressure can be caused by very high liquid temperature.
3. a pump running too fast - usually the pressure will build up at first flow restriction - CPU blocks are restrictive.
the 2 and 3 are not supposed to happen if the 1 is properly done. like the fittings should be capable of holding couple of bars - way more than what should be in a loop.
what you can do:
* do not apply lubricates of any kind on orings - just use water (rebuild your loop)
* slow down the pump - for your loop, even 3000RPM is way too much.
may be changing tubes as not all of them made with required precision - kinda cheap to replace.

As I stated in the original post. The computer was off, and hasn't run in 2 days. The D5 is running at only setting 2 when it actually is on so thats not an issue. All fittings are the correct size and matched to tubing size (16mm). Many system builders use a dab of silicone with no issues, as have I for years, to each their own on that one.

 

[Jdieter91]

Marko55,

I agree with a chemical reaction, but as to what the chemical reaction is from, is what baffles me. I'm using the same water, silicone, additive etc in Mt other rig, My fiancés, brothers and a few friends. None have issues like this.
My only thought was possibly a chemical reaction due to the galvanic corrosion from the mixed metals, but I can't find any article etc regarding such things.

Thank you for the response, and to you as well nonsense.

 

[vinson.mai]

Did anyone actually find the answer to this? I had something similar happen, with my mini itx using alphacool fittings and chrome tubing. It seems to either have a minor leak or burst a pipe which has happened a total of 5 times, each time in different locations after I had secured each leak location. This only occurs after reaching around 60-65 degrees which is quite high I understand, but may be amplified given how small headway my total volume in my loop would be significantly smaller. Hoping to seek clarity around this, even though this thread hasn’t been used in awhile!

 

[n0ns3ns3]

If you looking for a cause/solution, start your own thread with as many details/pictures as possible.
there is no single answer for all issues.
65C coolant temp is a lot - volume is not really important. a simple answer would be - try to use a pressure valve or have some air volume in reservoir or (temporary fix) just open a cap on res when the system is at full load to release the pressure and re seal it.
from my experience, coolant temperature fluctuation withing 15C (system off vs full load) does not cause pressure build up that can end up in tubes pop up.
As general rule, avoiding mixing metals/materials and aggressive coolants (especially with PETG tubing) solves some problems.
Anyway, this type of problems means that there is something wrong with the system - was not planned or built properly.