Thread sizes

TheCenturion · 16 Aug 2010 at 01:23

Hi guys,

I think I'm getting to the point where I know enough about watercooling to be confident enough to do it myself. Something has been bugging me. The rad that I want to use is the 140.3 Thermochill. But this thing has a G3/8" thread. Yet there are no G3/8" barbs/compression on OcUK. Will there be any added anytime soon?
Also, the rest of my system will be G1/4" parts. I haven't missed some crucial information where all the parts have to be the same thread size have I?

I know that these are pretty basic questions, but as this would be a first time system, I want to minimise the opportunity for error

thank you

JeffyB · 16 Aug 2010 at 01:32

If you want to use compressions you'll just need a couple of g3/8 to g1/4 convertors for the rad, search for "Reducing Socket from G3/8" thread to G1/4" with O Ring"

If you use barbs you can simply get g3/8 barbs

I have just noticed that thermochill make some g3/8 compressions themselves but only for 1/2id 3/4od hose.
http://www.thermo-chill.com/product...roduct/g38-to-12-id-34-od-compression-fitting

Bubo · 16 Aug 2010 at 09:50

anant_shah94 said:
Also, the rest of my system will be G1/4" parts. I haven't missed some crucial information where all the parts have to be the same thread size have I?

No, the water doesn't care what thread size it has to go through at any point in a loop. You could have a bucket sized fitting and a needle sized fitting on one block and water would find its way through. Although this extreme example would actually result in a noticeable detrimental pressure drop, when talking about G1/4 and G3/8 the pressure drop difference is negligable (though infact the pressure drop across the G3/8 fitting *may* actually be lower than the G1/4, it depends on the bore size and geometry)

TheCenturion · 16 Aug 2010 at 10:30

JeffyB said:
If you want to use compressions you'll just need a couple of g3/8 to g1/4 convertors for the rad, search for "Reducing Socket from G3/8" thread to G1/4" with O Ring"

If you use barbs you can simply get g3/8 barbs
I have just noticed that thermochill make some g3/8 compressions themselves but only for 1/2id 3/4od hose.
http://www.thermo-chill.com/product...roduct/g38-to-12-id-34-od-compression-fitting

Thanks. I reckon I am going to use 1/2id 3/4od tubing anyway so that's lucky! I reckon I'll go with the thermochill compressions in the end. That's really helpful thanks Jeff

Bubo said:
No, the water doesn't care what thread size it has to go through at any point in a loop. You could have a bucket sized fitting and a needle sized fitting on one block and water would find its way through. Although this extreme example would actually result in a noticeable detrimental pressure drop, when talking about G1/4 and G3/8 the pressure drop difference is negligable (though infact the pressure drop across the G3/8 fitting *may* actually be lower than the G1/4, it depends on the bore size and geometry)

Yeah, I was thinking that it would change the pressure. hopefully not too much though. Thank you

twist3d0n3 · 16 Aug 2010 at 11:17

wouldn't it be slightly beneficial to have to water moving slower through the rad, thus allowing for more heat to be transferred?

JeffyB · 16 Aug 2010 at 11:33

Flow rate has little effect on cooling performance, so long as its moving. Same goes for tubing size, makes practically no difference.

TheCenturion · 16 Aug 2010 at 11:34

those thermochill g3/8" compressions actually look quite nice. when the time comes, I'll settle on them

JeffyB · 16 Aug 2010 at 11:38

They also do g1/4 for the rest of the loop if you like them

TheCenturion · 16 Aug 2010 at 11:39

JeffyB said:
They also do g1/4 for the rest of the loop if you like them

Yes indeed

But... at 85p those feser ones are poking out at me for the G1/4". It's just too good a deal

JeffyB · 16 Aug 2010 at 11:42

Yeah they are rediculously good value.

TheCenturion · 16 Aug 2010 at 11:44

Oh carp. Just realised they're for 3/8" ID. I guess I'll probably go with the thermochill G1/4" as well, but the bitspower, while expensive, look really nice. And, if I'm already shelling out for a system, a few extra bob on nice fittings is nothing

Bubo · 16 Aug 2010 at 11:49

JeffyB said:
Flow rate has little effect on cooling performance, so long as its moving.

I wouldn't go that far tbh, like most things there is always a law of diminishing returns by chasing after extreme flow, but I wouldn't reccomend totally ignoring the effect of matching the power of your pump to the pressure drop of your loop to ensure you get a reasonable flow rate.

JeffyB · 16 Aug 2010 at 11:50

Thats how the cost spirals, my build went exatly the same way. Although the feser compressions i used came in blister packs of 4 and were £10.30 a pack (out of stock now though) which is pretty reasonable.

JeffyB · 16 Aug 2010 at 11:54

Bubo said:
I wouldn't go that far tbh, like most things there is always a law of diminishing returns by chasing after extreme flow, but I wouldn't reccomend totally ignoring the effect of matching the power of your pump to the pressure drop of your loop to ensure you get a reasonable flow rate.

Gabe from swiftech tested this, yes provided you dont have anything too restrictive but very few components are that restrictive these days, it makes next to no difference.

http://www.xtremesystems.org/forums/showthread.php?t=253337&highlight=flow+rate