Quick Disconnects: Koolance QD3/QD4 vs EK QDC?

[Dominic-Toretto]

In the market for 4 sets of quick disconnects for my system. I have read around and generally the QD3 is very very highly regarded. However I have read that the QD3's sealing Orings swell when these are connected for long periods of time and will cause it to dribble.

Allegedly QD4's have less restriction than QD3's.

And then their are the EK Quick Disconnects that are used in medical applications. Seem to be rated very highly, but no where near as widely adopted.

Ignoring the fact that any of the above 3 are impossible to find in the UK at the moment. What are OCUK's thoughts on this? Should I go for the EK's or the Koolance?

Edit: Reading lots of reports that the Koolance QD's will corrode and get stuck open, any truth to this?

 

[Dominic-Toretto]

Just had a think about this from an alternative perspective. Why can we not use ball valves to achieve this functionality? IE: If we have 2 lines on the CPU block. Put a ball valve on the inlet and outlet lines, straight after put a Y splitter after the initial ball valve on both sides, and then apply a second ball valve to the y splitter that is shut when the loop is operating normally. When you want to disconnect the cpu simply shut the primary ball valves on both sides. Open the secondarys off the y splitter to drain the remaining fluid in the cpu block. Snip the 2 lines going to the cpu and lift. You can then put a cpu back in and quickly join your 2 lines back.

It is not ideal having to snip 2 lines but it beats having to drain and dismantle the entire loop! Any thoughts on this working? Would not see the flow restriction hit either like QDC's. Drawn up a quick diagram below in case my drunk rambling thoughts don't make sense.

Loop running normally

Need to swap out the CPU quickly

 

[momo56]

Koolance ones are old doubt they are even made anymore.

Look for the 'Alphacool Eiszapfen' if you want to go that route. They work the same way, Alphacool probably copied them.
I've got a couple in my system. The black ones had an issue where the paint came off but I don't see corrosion being a problem with decent fluid.

The ball valve method would work but you would lose a lot of liquid each time. Hassle to refill. Also the amount of extra fittings needed/ will look messy.

The EK ones are OK but bulky and ugly IMO.

 

[Jokester]

The issue with the QD3s sticking open was limited to the black ones with black coated internals. They don’t make anymore, been replaced with models with bare metal internals like the silver version. You can still find the full black versions online though, avoid them like the plague.

QD4s are massive and total overkill.

I use 6 pairs of the QD3 in my loop and still manage good flow rates.

I believe the Alphacool model mentioned above is very similar to the QD3.

 

[bjmnz]

I've had a fully external loop with QD3's (2 pairs) for around 5+ years, recently stripped the loop out and they didn't leak. They were a bit stiff though. Would have last been apart around 12 months ago. That was a mixture of the short and long versions of 3/8" x 5/8" equivalent silver ones.

 

[ozorfis]

To whom it may concern:

I have 8 pairs coolance QD3 nickel plated. All female connectors are stuck wide open after few weeks. I had known about the black ones having issues with corrosion but the nickel ones although not showing any sign of corrosion from the outside are stuck wide open still. I totally regret the buy as they are almost useless. You cannot trust them to seal properly and have to drain the whole loop each time.

 

[Sin_Chase]

I've had QD3s in my system for many years without issue. I run premix clear fluids with no other additives or dyes. Had them in both soft tubing and hardline custom loops.

 

[Mcnumpty2323]

also been using qd3 silver version for many years
no issues at all with mine
and yeah would be possible to use ball valves
with a T piece between them to empty

 

[qbhatti]

Koolance ones are old doubt they are even made anymore.

Look for the 'Alphacool Eiszapfen' if you want to go that route. They work the same way, Alphacool probably copied them.
I've got a couple in my system. The black ones had an issue where the paint came off but I don't see corrosion being a problem with decent fluid.

The ball valve method would work but you would lose a lot of liquid each time. Hassle to refill. Also the amount of extra fittings needed/ will look messy.

The EK ones are OK but bulky and ugly IMO.

I know this is an old thread but which alphacool ones are you using? I have 19/13mm soft tubing in my system and am keen to use QDCs.

 

[momo56]

I know this is an old thread but which alphacool ones are you using? I have 19/13mm soft tubing in my system and am keen to use QDCs.

Lol ignore what I said above. Had multiple alphacool ones fail since then.

Turns out they still sell the Koolance QD3s, im using those and have been amazing.

I think they sell 19/13 versions. They definitely have g1/4 female threaded options to add your own fittings on.

 

[Mcnumpty2323]

Yeah they do 3/4 inch ones (koolance)
Guess that's 19/13mm in new money lol
Or at least did when I got mine
I actually got 16/10mm tubing to fit
On them by shoving it in a cup of boiling water
Sold them on mm now
Those things were solidly built

 

[qbhatti]

I am so confused as to which ones to get though - there is no stock of QD4 in the UK. I was thinking of getting those EVERIS LQ6's when I was able to get them for a steal (but 3/8 hose).

So what do I actually need if I want to stick a barb or other fitting on the end of it?
if someone can point me in the right direction then I can get on with it.

 

[pre]

I am so confused as to which ones to get though - there is no stock of QD4 in the UK. I was thinking of getting those EVERIS LQ6's when I was able to get them for a steal (but 3/8 hose).

So what do I actually need if I want to stick a barb or other fitting on the end of it?
if someone can point me in the right direction then I can get on with it.

I am one of those people still using QD3s and 19/13mm.

You need a "male" QDC and a "female" QD part for point you want to disconnect between if you are going with Koolance. You can get a "threaded" male or female part that has a normal g1/4 bspp - eg QD4-FSG8 or QD4-MSG8 - that screws into a rad/pump/block/fitting and non-threaded parts - eg QD4-FS13X19 and QD4-MS13X19 - that can either connect to each other if you are using it between two ends of soft tubing or to the opposite sex part in threaded part so you can disconnect directly off the inlet of something.

Note that the QD4 parts are very heavy and large if you are using them for something other than a drain you will want to use QD3s instead. I don't think any UK WC retailers actively stock Koolance parts anymore so you might have to look for an EU retailer or Koolance direct.

 

[Jay85]

I switched over to Koolance QD3's after my Alphacool ones got stuck. The Koolance ones have been solid performers, i've got a mix of black and silver ones now and both work really well.

 

[Sin_Chase]

Used my QD3s again this week when draining and filling my loop. Still impressed with the quality and effectiveness of them!