Testing WBs is difficult, and it does involve a fair amount of work, any way you look at it.
About the flow rate test: It is important to know the flow restriction of a waterblock. The less restrictive it is, the more flow it can handle, which could be supplied by a less powerfull pump. Now I know that even that's not clear enough... You also have to factor in the rad, seperately, since more heat will cause the rad to be more efficient, but will still cause the water temp to be higher, something to be avoided, if possible.
The water tap idea may not work, because it may not achieve the desired flow rate, plus you really can't be sure that it's steady pressure or temp, for that matter.
I thought that it might be best to use a big pump, and just put a restriction on it (valve), to reduce the flow rate to the desired level, but that big pump would induce a fair amount of heat, so it's only good for flow testing.
Since the end user will buy an off-the-shelf pump, there is not only a limited range of flow rates that will end up being used, there are actually very specific flow rates that will be achieved, but since there is quite a large number of pumps out there, it becomes quite unreasonable to test every single model.
Also, the end user may end up using just about any rad, and that in itself is a large variable, for both flow and temps.
|