Patent ID: 8613730

Claim:
A method for disabling a fluid pressurizing unit of a fluid injection system, the unit including a plunger shaft, a syringe and a plunger, and the method comprising: isolating the syringe from all downstream flow paths of the pressurizing unit; retracting the plunger shaft and the plunger simultaneously from a first position to a second position, both the first position and the second position being within the syringe, such that a vacuum is created within the syringe downstream of the plunger; the plunger being operably engaged with the plunger shaft at the first position; and the plunger being adapted to disengage from the plunger shaft at the second position, and to move back toward the first position upon disengagement from the plunger shaft, wherein an inner diameter of the syringe is larger at the second position, than at the first position, so as to facilitate the disengagement of the plunger from the plunger shaft.