Abstract: The valve described herein comprises a movable core (28) which is drawn toward a fixed core (21) once the valve is opened by excitation of its coil, or solenoid (24). The valve's needle-obturator (17) is capable of moving axially with respect to the movable core (28) but, upon the coil's being excited, remains thrust into the orifice (16) during a first opening stage while the movable core only (28) is caused to rise. Subsequently--once the movable core (28) arrives within a few millimeters of the fixed core--a shoulder (51) offered by the movable core to a shoulder (18) incorporated in the obturator (17) duly makes contact and draws the latter upward, whereupon the action of a spring (27) overcomes such resistance as is offered by a further spring (19) and the obturator itself (17) is raised to a generous distance from its seat in orifice (16) aforesaid.