Wish they gave more info on the pump. It looks like a shallow well pump, which should be capable of 50psi.

In a setup like that, the pump will come on with a pressure drop (maybe 10psi?) not from volume moved. Make sure you set the air pressure in the tank to whatever the max pressure you can get out of your well pump so that you get max pressure output untill pump kicks in again.

Hope it works for you this time, and good luck.