F 350 4WD Super Duty V8-6.4L DSL Turbo (2008)
^ The valve mushroom is held in a closed (sealed) position whenever the Piezo Actuator is not energized via high pressure fuel and spring pressure.
^ The control piston utilizes its large surface area for a downward force to overcome the pressure exerted by the smaller surface area of the nozzle
needle in the high pressure chamber to keep the nozzle needle in a closed position.
Nozzle Needle
^ The nozzle needle is an inwardly opening type which lifts off its seat every time the pressure in the high pressure chamber exceeds the pressure in the
control piston chamber i.e. when the piezo is actuated.
^ The needle control spring is used to hold the nozzle needle in a closed position.
^ Fuel is atomized at high pressure through the nozzle tips six spray holes.
