The impact of tubing sizes

[migueld]

There are always engineering reasons for why things are the way they are, or why things changed from what was expected. The true way forwards is through scientific analysis, understanding, modification and refinement. Not romance.

Sure, just don't get too comfy with equations. Romance may actually give some interesting ideas

[Cathar]

Or just be a way to make money off the gullible.

[LogAn'sRun]

Or just be a way to make money off the gullible.

uh thanks cathar, and i had just finished my breakfast. . .

[dinos22]

Stew
what sort of liquid do you use....and do you use any additives to prevent jets from blocking?

[Cathar]

Stew
what sort of liquid do you use....and do you use any additives to prevent jets from blocking?

Filtered tap water. No additives. Have a silver block which acts as a natural biocide. Never had any issues for 30 months straight now with the exact same water that I stuck in all that time ago (I have a reservoir). The same system had a G5 in it before, and now a G7. The odd time I've opened up the blocks up they've been as clean as new. Not one single jet has ever been blocked, and this is even on a G7 which has ~1/50" (~0.5mm) diameter jets (i.e. ~40% of the orifice size of a regular Storm that most people know).

Seriously, it's the additives that most people stick in that causes blockages. Clean your system's components out correctly at the beginning, filter your water, and use a natural biocide (aren't silver blocks nice? ), and there's never a problem.

The "worst" problem I have is that my tubing has gone slightly cloudy, but it's still translucent.

[sc00p]

(aren't silver blocks nice? ), and there's never a problem.

Actually that brought to my mind the only reason why I would ever use reservoir. I could drop a silver coin bottom to the res Thanks for the idea Cathar

[MaxxxRacer]

There are always engineering reasons for why things are the way they are, or why things changed from what was expected. The true way forwards is through scientific analysis, understanding, modification and refinement. Not romance.

But I like romance . It solves all problems. I swear it does!

[septim]

hmm do we hear wedding bells soon....

[JargonGR]

Actually that brought to my mind the only reason why I would ever use reservoir. I could drop a silver coin bottom to the res Thanks for the idea Cathar

I am doing this in my 3 loop system using silver wire in each or my reservoirs and 3-4 months not the tubes are clean. As Cathar said my only problem is that tubes go a bit cloudy but he water on the Reservoirs is still transparent.
I am not using any additives just pure medical (and cheap) Water for Injection.

I am wondering if there would be any clouding if we could use (in thery ofc) tubes made of glass. I guess not.

[SiGfever]

I also run two silver wires in my Micro-Res.

When I redo my loop I will leave the CPU circuit 7/16" and do the GPU and NB in 3/8" with the push fittings that Cathar listed from McMaster. I will run another DDC-2 w/Alphacool top mounted to my MM hard drive brackets. Those push connect fittings look very interesting.

I just wish that I had more trust in the DDC series pumps because the size is excellent for case placement.

[gabe]

3/8" ID | 1/2" OD into 1/2" ID push-fittings is ideal

Stew:

I don't have too much time to post right now, so I'll go quick: please investigate minimum pressure specs for push-in fittings. As you know, I have tremendous experience with these, and I didn't give them up commercially without solid reasons..

Negatives in a nutshell:
Safety
- push-in fittings were designed for applications where pressure is <2-7> bars. They were never intended for low pressure environments.
- If you are going to use vinyl tubing and push-ins be aware that over time the tube seriously indents at the o-ring level, resulting in reduced o-ring compression and poor seal -think of the effect of a bend in the tubing at proximity of the fitting opening with an under specs seal! Furthemore tolerances in vinyl tubing OD often exceed those of most push-in fitting brands.
Other considerations:
- great to install, horrible to remove for the inexperienced
- expensive


Final consideration: In an extended use scenario, vinyl tubing is counter-indicated due to its high porosity. Alternative low porosity tubing does not work well with push-ins (in our application) for multiple reasons e.g.: hard tubing like polyethylene has low bend radius, and soft tubing like norprene is too soft for adequate seal.

Final final: the reduced pressure drop benefit offered by push-in fittings is incremental at best. Convenience of utilization for trained users prone to install/uninstall frequently is priceless. But they have lost MY vote of confidence for long term/no maintenance systems at this point.


Other than that, thanks for the thorough survey!

[migueld]

Gabe thanks for the information, your experience with push-in fittings is greatly appreciated.

I guess if there will be a shift in fitting usage it might have to be the compression type.

[Cathar]

Thank you very much for the valuable insight Gabe, especially from one with long-term experience with such fittings.

In your experience, does the use of the tubing brace inserts with soft-walled tubing alleviate the stated issues to a significant degree? Much of what you stated seemed to focus around the use of tubing without inserts. Forgive me if I misunderstood. The inserts offer far less of a restriction hit than barbed fittings, and I can easily remodel the impact of using inserts with push-fits.

[gabe]

Thank you very much for the valuable insight Gabe, especially from one with long-term experience with such fittings.

In your experience, does the use of the tubing brace inserts with soft-walled tubing alleviate the stated issues to a significant degree? Much of what you stated seemed to focus around the use of tubing without inserts. Forgive me if I misunderstood. The inserts offer far less of a restriction hit than barbed fittings, and I can easily remodel the impact of using inserts with push-fits.

Tube inserts are mandatory use with vinyl tubing. I wouldn't even dream about installing vinyl in push-in fittings without them. So I am confirming that my observations are with tube inserts.

One thing that helps is to use a locking clip. It clips on the collet, effectively keeping it in the out position. Gives a little more support to the tube and reduce lateral pressure on the o-ring. But still, these fittings are working out-of-specs in our environment.

I am curious: Why concern yourself with a .125" reduction over a few inches when you just demonstrated that the same reduction over several feet in a typical cooling loop is only affecting temps by a mere ~1C ???

Push-ins are elegant and attractive to our kind, but in my experience they represent a possible hazard unless one refills/maintains the system every 6 months to a year.

Don't get me wrong: I still use push-ins in industrial apps where system pressure is 45~60 PSI. In such apps, they are absolutely flawless. Just not in your typical PC cooling system.

[Cathar]

I am curious: Why concern yourself with a .125" reduction over a few inches when you just demonstrated that the same reduction over several feet in a typical cooling loop is only affecting temps by a mere ~1C ???

'cos sudden contractions of 0.125" are significantly more expensive (PD wise) than some run of tubing length of equal diameter. Compare the modelled 8mm over barbs to the modelled 8mm with push-fits.

The goal (well, my goal) is to find a solution that uses the thinnest possible tubing that offer no performance impact greater than ~0.2-0.3C over a 1/2" barbed solution. A 1C difference is unacceptable to me, but that's just my choice. Others have their own preferences for what's acceptable.

Perhaps soft tubing stretched over compression fitting orifices may be the other viable solution?

[gabe]

The goal (well, my goal) is to find a solution that uses the thinnest possible tubing that offer no performance impact greater than ~0.2-0.3C over a 1/2" barbed solution. A 1C difference is unacceptable to me, but that's just my choice. Others have their own preferences for what's acceptable.

Just watch your fluid levels often, is all I can say.

[Cathar]

Just watch your fluid levels often, is all I can say.

Agreed. My personal preference is for no thinner than 3/32" walls (or 2.5mm), for just that reason. Also helps for turning radius too. I didn't state that in my OP though, but I am aware of tubing evaporation/porosity issues, and turning radius issues, for thin walled tubing.

[Top Nurse]

I think all the negatives about push-fits can be summed up as a size thing. These types of fittings have been successfully used in a wide variety of uses in water cooling by European manufacturers though they aren't typically using the sizes that have been discussed here (12mm). I can see that the bigger the OD of the tube the more there is a torsional force at play that could conceivably cause a leak. In my Legris fittings the tubes go in a long ways so there would have to be a severe side stress for them to leak.

In my Aqua Computer manuals they all explain exactly how to connect these types of fitting. They also stress that you should cut off approximately 2mm of the tube every time you remove and reinsert the tube for security purposes.

[Top Nurse]

Perhaps soft tubing stretched over compression fitting orifices may be the other viable solution?

I tried that approach and it is somewhat problematic as the screw down ring is specifically made for a specific size tube. I did get it to work, but I had to use a lathe to get the nuts ID opened up.

[mukmaster]

Very nice guide !!!
Easy Simple Effective

[LogAn'sRun]

Top Nurse, do you have pics of your rig somewhere so I could look at those fittings?

[sbrehm72255]

She has a work log over at the [H], but last I checked, it still hasn't been finished.

[Halk]

She's got 2 worklogs going. There's Feeding Frenzy and there's Feeding Frenzy Interlude. They're both great reading, with good pictures.

[RickCain]

Top Nurse, do you have pics of your rig somewhere so I could look at those fittings?

You would have to visit her work logs on [H] but here is a picture of the push to fits she talks about.

[LogAn'sRun]

thanks, is that 8mmID tubing or 10mmid??