Overheating issues

92b said
It will only vent an insignificant amount so for the practical purposes needed for a properly working cooling system it is not vented. Once the pressure is equalized at 7psi between the tank and radiator it will increase in pressure until it reaches the pressure of the cap on the reservoir. Then it will vent like a properly working cooling system is designed to vent.

I'll vent the difference between the 7PSI cap and the 16PSI cap. I guess that's insignificant? Regardless, the radiator is still vented TO the overflow. It's a silly argument, since the example is just that. An example that doesn't exist. Maybe a better word we can agree on is "expansion" rather than venting?