Dean, you can pressurize PVC up to at least 50 PSI without any problems, but you better be sure your glue joints are good..as for sputter, that will only happen if the water level gets down to the spigot..so a full tank will start off with 50 PSI and then the pressure would decress as you use water, but it should be enough to push all the water out with a good flow.
this is assuming the spigot is at the lowest level.