An injector having a tube attached to an armature. The injector includes a solenoid portion and a valve portion controlled by the solenoid portion. The armature includes a small diameter portion. Also included is a tube having a cavity, a first end of the tube is connected to the small diameter portion, and a ball is connected to a second end of the tube, such that the ball is selectively in contact with a valve seat. A hermetic weld connects the ball to the second end, and at least one heat affected zone is located in proximity to the hermetic weld. A coating substantially surrounds the heat affected zone and at least a portion of the ball, such that the coating prevents the heat affected zone from being exposed to diesel exhaust fluid and thus subsequent corrosion.