The impact of tubing sizes

[Berg]

berg,

missing a word on the 11x8mm PVC tubes. could this be a good compromise having the advantages of both worlds:

• 8mm ID
• 1.5mm wall size, which gives a bit more stability
• cheap and more flexible than PUR

what's your opinion on this one?

Yes I decided to leave the 11x8mm (and others) for later, otherwise I fear the first post would have been too long - I can ramble on about hoses and fittings all day really

But you are right: 11x8mm PVC, with 1,5mm sidewalls are a good compromise also. This hose started seeing use, as a result of the problems I mentioned with the standard 10x8, which has only 1mm walls, and collapses much to easily. There is a Tygon 3603 which is 11,2x8mm and that has some succes over here, but is too expensive I think, and you need special 11mm compression nuts for the fittings - you can't just use standard cheap 10/8mm Push-ON fittings like you can with 10x7mm tubing (which is available in a very nice Clearflex version).
We have also been selling (and using) this 11/8mm combo, but personally I still prefer the 10/7mm for 3 reasons:
1. Fittings and hose are cheaper.
2. The hose has a smaller bend radius.
3. The flow advantages of the slightly larger 8mm ID are probably marginal at best, as the fittings used are still only about 6,9mm ID (as also shown by Cathar's graphs) - where as with the 7mm ID, there is hardly any ID flow restriction going through the fittings.

BUT 11x8mm PVC is sure much better than 10x8 PU or PVC - so not a bad choice at all.

As the hose ID gets larger, the sidewall thickness also needs to increase to still have a good bend radius, so something like a 12x8 with a Push-On fitting with ID of 8mm would be really great. (and guess what diameter Zalmans blue hose is.. yes 12x8mm exactly. Sometimes the big companies do get it right!) Only problem is that sourcing the fittings and hose for this size is not easy. I have only been able to find suitable fittings in plastic, and we really prefer nickel plated brass (with o-ring sealing).

[Berg]

Marci >> Yes, with tube end inserts, 10x8 pvc could be used in Push-IN fittings, but the hose is still crap due to the 1mm thin sidewalls.
I have never seen tube end inserts for 7mm ID, but maybe they are around somewhere. I wonder if they wouldn't cause some flow restriction themselves though - which would make them a bit pointless.

Turtle 1: >> Yes I noticed you said something about multiple loops earlier - which is really the only way to go when you have more than 2 or 3 waterblocks if you ask me. Solves pretty much all flow problems.
When you say "complete flow control system" do you mean you have valves for each loop? - or something different? - have any pics?
I started using seperate ball valves for each loop in my own systems a few years ago, so I could control and balance flow for each block as I wanted. I use little anodized aluminum manifolds with 1/4" thread, where you can put in a row of ball valves if you like: http://www.vcore.dk/shop/pro-mini-ventil-1-975p.html
(have not been able to find a similar manifold in copper..) - usually I will have a 3/8" ID feed into the end of the manifold, and then ideally an identical unit after the waterblocks to join the small ID hoses again - and meet in a 3/8".
This type of solution is not really necessary for most people though, but is nice for the "control freak" - and really nice if you are often replace a waterblock or fiddle with the system, as you can shutdown and isolate any one block without having to drain the entire system!

[Turtle 1]

As I already said I like the way you think.

We are working with these now both the W098/ $798 and the W099/ $1,124. Yep thats expensive but we really don't care.
http://www.emiplastics.com/water_regulators2.htm

These are available also but their not what we want . They are way cheaper tho.

http://www.emiplastics.com/water_regulators.htm

As for manifolds I like stainless steel . You can get those here or make them as we do .

http://www.plastixs.com/burg01/b01_03.html

look around on this site they got some nice stuff .

[LogAn'sRun]

As the hose ID gets larger, the sidewall thickness also needs to increase to still have a good bend radius, so something like a 12x8 with a Push-On fitting with ID of 8mm would be really great. (and guess what diameter Zalmans blue hose is.. yes 12x8mm exactly. Sometimes the big companies do get it right!) Only problem is that sourcing the fittings and hose for this size is not easy. I have only been able to find suitable fittings in plastic, and we really prefer nickel plated brass (with o-ring sealing).

McMaster has Tygon 3603 in those measurements with 2mm walls, which is almost what Cathar wished for wall thickness somewhere else in this thread (if I remember right, he wanted 25mm). Anyway, have you tried Legris fittings? Don't they have some push-ONs that would work with that? What's the disadvantage of plastic vs metal fittings?

[Berg]

McMaster has Tygon 3603 in those measurements with 2mm walls, which is almost what Cathar wished for wall thickness somewhere else in this thread (if I remember right, he wanted 25mm). Anyway, have you tried Legris fittings? Don't they have some push-ONs that would work with that? What's the disadvantage of plastic vs metal fittings?

Yes a Tygon 3603 with 8mm ID and 12mm OD, would be just about perfect as such. The problem lies in finding the matching Push-On (compression) fittings - which I have not been able too. As Waterlogged also said, Tygon 3603 (and all other nice soft PCV based tubing) is to flexible for use in Push-IN fittings - like Legris. The Legris are great, except you need a stiff PU type tubing to have a secure connection, and even then you may have trouble in some negative pressure situations as described earlier in the thread.
That is why Push-ON type fittings are a better solution - especially for larger diameter and softer tubing.

Plastic vs. brass: Plastic is just fine for Push-IN, but for Push-On brass is better due to the thread strength and holding power of the compression nut.
- also they look nice and shiny