George is right on target. I ALWAYS suggest the shutoff valve to be placed before the pump! A runaway pump can either rupture a line or blow the line off the fitting when abruptly closing the valve on the pressure side, IT HAS HAPPENED and the results are not pretty! If installed before the pump, the pump will simply cavitate, no further fuel will enter the engine. If there is nothing entering the pump, nothing can exit!
For safety sake, place the shutoff before the pump