A reservoir on itself doesn't do anything, to eliminate the negative pressure difference between the pump input and atmospheric pressure there needs to be an opening from the input of the pump to the atmosphere. There wont flow any air or water because of that opening, it just equalizes the pressures. Look at it as an electric circuit. The pump is the battery, the pressure it generates the voltage and the waterflow is the electric current. The pump forms a circuit with the watercooling blocks, the battery forms a circuit with equivalent resistors. the resistance determines how much flow / current you get given the pressure / voltage. You can ground the electrical circuit at any point. The part of the circuit you ground has the same voltage level (pressure) as the ground but all the voltage differences / pressure differences along the circuit are unchanged. You will have the same current / flow as before. So you can simply put the pump input at atmospheric pressure without changing anything in flow. Since the input of the pump is the lowest pressure point in the loop all the other points in the loop will have positive pressure relative to the atmosphere. So non of your tubes will be sucked flat by the pump.
If you had a small hole somewhere in your loop ( a single one) you might not have noticed since the pressure will quiqly equalize with the atmosphere and you'll get no flow of water out of this. When you open up your reservoir before the pump suddenly all other pressures in your loop will become positive and that small hole will start leaking big time.
Instead of a reservoir you can put in a T line before the pump. Just have the loose leg stick above the rest of your circuit and you'll have a low negative pressure before your pump again.
So the whole circuit can have one open spot to the atmosphere. It won't affect the performance of you loop in any way.
|