When electromagnetically excited, the sealing armature is moved away which cancels the sealing function and releases the passage. Thus, on the 2-way plunger-type valve, the core spring, assisted by the medium pressure, forces the valve seal onto the valve seat and closes the passage. After energization, the core is pulled with the seal into the solenoid coil. The valve opens. In this case, the electromagnetic force must be higher than the sum of spring force, static and dynamic pressure force.