Zalman block, NPT or BSP?
 

Does anyone know the threads are NPT or BSP?

I've included a close up picture of the barbs.

Can I use NPT barbs and fit into BSP or vice versa?

More than likely it is BSP because it has an o ring. You cannot interchange them.

I was planning to mod the brabs on the block using the Dangerden High flow fittings here, which also has an O-Ring. http://www.dangerdenstore.com/produc...&cat=34&page=1 So having O-Ring doesn't mean it's BSP, right? I'm pretty sure Dangerden uses 1/4" NPT...

NPT is designed to seal itself with a taper. Anything with an O-ring does not need a taper to seal.

What makes these "high flow" fittings better?

I am 99% sure DDs hiflow barbs are a reg 9/16 thread with an O-ring to seal

DUH it says it right in the page you linked. (I should of looked 1st)

This is almost certainly1/4 BSP. EldonJames makes 1/4BSP to 1/2" ID tubing barbed adapters. As I remember, these had a very large ID (don't have one to hand to measure). You can get them at mcmaster-carr (and most likely other places like usplastic). I think they were $3 or $4 for a package of 10.
These fittings were not o-ringed (although you could add one if you like). I just add a tiny dab of teflon paste to the portion of the thread that is not going to come in contact with coolant and have never had one leak - but I'm not dealing with high pressures, being a watercooling-for-quiet kind of guy :)
Oh - these fittings are nylon, which means that you can cut them off (careful what you do with the leading thread, use a knife, not a saw) to control how far in the fitting goes. Pay attention to interior flow issues as a fitting end protruding too far in might hurt (depends on the wb).
Finally (and IMO, of course) these EJ "single barb" fittings do a really good job sealing to tubing as the tubing can "relax" back to its natural ID once past the barb.

[edit]
If this block is completely hollow and the inlet is above the CPU contact area, try using the block with the (new, longer) BSP fitting screwed all the way in. Older swiftech blocks, which were like this actually benefited from the inlet stream being a bit more focused in this area - which was something you could do by brazing/soldering an extension on to the fitting - but you've got BSP, so you can just thread it in a bit more... [/edit]

AFAIK you can use straight male fittings with tapered female ones. It's a "make do" kind of thing, though.
Even tapered fittings don't do a great job with high pressure unless you torque the fittings to the point that there's a bit of thread deformation.
As a side issue, fittings with asymmetrical thread profiles work much better. NASA's starting to use them, and, interestingly, they were a part of the whitworth (woex) thread standard from the 1870s or so (locomotive steam fittings). Re-invented or re-discovered in the standard...

Thanks for the reply. I'm still a noob at this. So the best solution for me is to get 1/2"OD 1/4"BSP fittings, I guess.

Does EHEIM 1048 use 1/4"NPT or BSP? I don't have the original fittings, since it was from an old Swiftech kit which uses restrictive quick connect 3/8" OD fittings.

Zalman block uses a simple side-to-side design, so it probably wouldn't benefit from using longer thread.

AFAIK, neither, but a non-tapered metric thread.
The easiest thing is to get adapters intended to allow you to fit the Inovatek compression fittings - and screw the 1/4 BSP to 1/2" ID tubing adapters into them.
I just did a google search on 'em and the first one in the list is Sharka Computer.
Contra-wise, think about using a AGB-O-Matic as a connection to your inlet (pump inlet just pushes in.). Yup, that fitting you see on it is 1/4 BSP. Makes filling your system easy...

I just had a look at the old push in fittings that came with the pump, and it stated BSPT. So I think I found the answer! :D

Now I need to find a 1/2"ID 3/8" BSPT for the pump intake without needing to buy a pack of 10 from mcmaster...

Now I'm getting even more confused. According to here, it uses NPT! :shrug: http://www.cooltechnica.com/Merchant...egory_Code=TAF

Edit: I found the answer here. :D http://www.watercoolingshop.com/cata...roducts_id=165

Thanks again for your help! ;)