I’ve used those same fittings on my dads bobcat when changing out hydraulic implements. You are absolutely correct about bleeding pressure before disconnecting them. If you don’t, then you have to overcome the pressure in the line as well as the spring pressure in the fitting to get them to connect. It’s a bitch and a half when working with high pressure systems.
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it’s more about running a jacket at -60, unplugging it, and the HX fluid expanding. you can release the pressure when you disconnect, but without actually bleeding some fluid you can still get into trouble.
those particular fittings will handle the pressure…but what they’re connected to might not. having the the plastic ones fail struck me as a feature rather than a bug to be honest. I had multiple sets of the flavor that @Neutral shows…
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Oh! I understand now. Temperature differentials cause the fluid to contract at low temps and then expand as it rises back to ambient temp. I appreciate that info as I have not used this style of quick connect in a lab setting. I will definitely keep that in mind. I have only used the open style quick connect that does not retain pressure when disconnected.
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I’m not sure, they are hydraulic fittings though, and bobcat sounds familiar.
@cyclopath these are chrome plated steel, I’m sure plastic is much more prone to deformation. I also close the shutoff valve when it’s a room temp. I also only go to -40, may still be an issue but we’ll see. I’m switching to an x-spiral soon so it may not even be an issue.
@MedicineManHempCo these are for a simple coolant system that has a low-pressure recirculating pump, not for a hydraulic system. I have the female fittings on all the equipment and male on the tubing so I can hook up whatever system to whichever chiller in a few seconds without making a mess instead of taking an hour and needing to replumb stuff for contracts.
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yep. those FITTINGS can handle the hydraulic pressure generated by your expanding HX fluid.
the question is; can your vessel jackets?!?
I totally agree that being able to replumb on the fly without loosing fluid is a great trick.
I’m just suggesting that there are some concerns. based on common sense (cold fluid WILL expand) and experience (I’ve had low pressure QC’s fail…better them than my jackets).
I’ve absolutely used the QC’s you show, and they’re great. I would probably only put them on the HOT side. eg they’re great for folks still using a detachable jacketed “shatter platter” on their rigs.
as far as “will this be a problem?” maybe add a pressure gauge behind one, hook things up and get them as cold as you can, then disconnect and see where things go.
just a short “pig tail” of flexible hose between the jacket and the QC is another solution. worst case scenario the tube bursts rather than your jacket.
I prefer to make inlet and return opposite genders. then the circulator can be trivially looped, and there is no disagreement about which direction fluid is supposed to be run through any particular jacket.
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It’s just hooked to the lid which has a ss coil on the other side. It likely can handle the pressure and there’s a small section of PVC tubing that will certainly burst before the steel.
I’ll take that into consideration on any lines I put in in the future.
That should suffice. 
As long as it has a decent diff …not like the new school With the cheap brake assist. I test drove a Focus ST when I sold cars, when you get any torque steer the ABS kicks in to modulate wheel slip since it has a cheap open diff… shits terrifying lol
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I need better plumbing skills, looks real clean. Good job
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Im really good at routing wires for rc helicopters but my gardens are a hot mess of cords and non osha safe environment.
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My wife hates making those😂
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I love making them. 
$7.00 every 20 seconds…lol
We let them dry in some of the shops we supply. Gets the shops smelling like flowers.
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Is that a picture of one-eyed Willie Nelson on the mantle?
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Good eye!
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10 years smoke free, still compulsively addicted to nicotine tho haha and eyes are to old to see the wires
It’s harm reduction right?
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My wook didnt smoke cigs, but his mom hates me so she tried getting him on ecigs instead of smoking my weed. Now he got addicted to it and smokes real cigs.