QOD 03-25-06 Private Water Systems

Another private water syatem question:

Sorry how would I know the answers? Correct me if I am wrong but wouldn’ t the settings be different for each situation depending on size of pump, incoming water line size from well, size of pre-charged tank, size of outgoing line from pressure tank?

either way, or size the rule is the same. pressure switched to turn the pump on or off work the same, which automaticly eliminates 2 answers. the last one may not be the exact # for every system, but it the right-est answer up there.

Pressure settings are going to be different, sorry I don’t see how anyone can say it is 2 psi either way it just is not the case in the real world.

The corect answer is C.

Every manufacturer of modern pressure tanks for household water systems specifies (thereby becoming “code”) that the pre-charge pressure on the bladder side of the tank be 2 psi less than the cut-in pressure setting. This allows allows for maximum utilization of the tank volume, and when sized correctly, prevents short cycling, bladder failure, and the resultant pressure spike at cut-out.

Just a note: Many Homers will adjust the cut-in/out pressure setting on the pressure swith to increase their shower pressure without re-setting the tank pre-charge pressure. This results in short-cycling of the pump.