First Watercooling Loop

Fittings

The biggest thing to decide with fittings is whether to use barbs or compression fittings. A compression fitting is essentially a barb plus a lockring that screws on to the barb and clamps the hose against the barb:

On the left side we have the barb – as you can see the lip of the barb is typically a bit smaller than the lip on a “normal” barb. There is also a screw thread at the base to which the lockring on the right will screw into once the tube is put over the barb.

My personal preference is to use compression fittings. They are almost as safe as a barb and a worm clamp, but look a lot cleaner. However the worm clamp with an old-school barb will be safer because the worm clamp is extremely unlikely to undo and can tighten easily to the point where the tube is being pushed around the clamp. The barb also has more bite to hold the tube on and of course you can use undersized tube to make the barb bite even more. Ugly barbs + worm clamps:

Some people of course will tell you that you don’t need clamps and that undersized tube will be safe. To this I would say maybe you should ask them to pay up if such a setup ever leaks on you. The reality is that tubing stretches over time and things that were tight may not be so tight in 6 months. Always use a clamp unless you are ok with the chance of killing your hardware.

The last point to talk about is teflon tape and o-rings. Teflon tape is designed to seal the thread of a fitting against the thread on the block/rad/pump. An o-ring is used to seal the body of the fitting against the body of the block/rad/pump etc. They are mutually exclusive because if you’re sealing one not only do you not need to use the other, but the other is extremely unlikely to be sealed. Both have their pluses and minuses, but almost every fitting available for sale in water cooling will use a rubber o-ring so teflon tape is not needed unless you’re going off road.