both the inlet port 20 and the associated circumferential free space 54 are blocked because the spring 44 presses the valve element v s by way of the stop 52 to the right against fixed seat ring 60 with this state of affairs a flow path extends from the connection 16 of the valve through a free space 66 continuing through a gap between the stop 52 and the inner sleeve 38 as well as another gap between the seat rings 60 62 and on into the port 18 it should be understood that although fig2 shows the seat rings 60 62 very closely together air still can pass between them now if the electromagnet 32 is actuated its armature 34 will exert pressure on the plunger 36 to the left in fig2 therefore the plunger 36 likewise moves to the left and the inner sleeve 38 too is moved to the left by the spring 42 until its left end edge hits the stop 52 thereupon the movement of the inner sleeve 38 is interrupted for the time being because the spring rate of spring 42 for instance is 20 less than the spring rate of spring 44 preferably the springs 42 44 are selected so that the pressure of the enclosed spring.