Fire extinguishing system comprising: a fire extinguishing medium container, a first and a second fire extinguishing sub-system, and a valve assembly fluidly connecting the fire extinguishing medium container to each of the first and second fire extinguishing sub-systems and arranged for selectively distributing fire extinguishing medium from the fire extinguishing medium container to the first or to the second fire extinguishing sub-system upon activation of the fire extinguishing system, characterized in, the fire extinguishing system further comprising a first and a second detection conduit arrangement (19, 21; 119, 121) connected to the valve assembly and configured to activate the fire extinguishing system, wherein the valve assembly comprises a valve chamber, a valve member being movably arranged in the valve chamber and a fluid passage portion being arranged in at least one of the valve member and the valve chamber, the valve member having: i) a first force receiving surface arranged to, upon activation, be subjected to a first force (F 1) exerted by a force applicator (19; 119a), being a pressurized fluid, of the first detection conduit arrangement (19; 119) and for moving the valve member to a first position, in which said fluid passage portion is aligned for distribution of fire extinguishing medium to the second fire extinguishing sub-system, and ii) a second force receiving surface arranged to, upon activation, be subjected to a second force (F 2) exerted by a force applicator (21; 121a), being a pressurized fluid, of the second detection conduit arrangement (21; 121) and for moving the valve member to a second position, in which said fluid passage portion is aligned for distribution of fire extinguishing medium to the first fire extinguishing sub-system. a fire extinguishing medium container, a first and a second fire extinguishing sub-system, and a valve assembly fluidly connecting the fire extinguishing medium container to each of the first and second fire extinguishing sub-systems and arranged for selectively distributing fire extinguishing medium from the fire extinguishing medium container to the first or to the second fire extinguishing sub-system upon activation of the fire extinguishing system, characterized in, the fire extinguishing system further comprising a first and a second detection conduit arrangement (19, 21; 119, 121) connected to the valve assembly and configured to activate the fire extinguishing system, wherein the valve assembly comprises a valve chamber, a valve member being movably arranged in the valve chamber and a fluid passage portion being arranged in at least one of the valve member and the valve chamber, the valve member having: i) a first force receiving surface arranged to, upon activation, be subjected to a first force (F 1) exerted by a force applicator (19; 119a), being a pressurized fluid, of the first detection conduit arrangement (19; 119) and for moving the valve member to a first position, in which said fluid passage portion is aligned for distribution of fire extinguishing medium to the second fire extinguishing sub-system, and ii) a second force receiving surface arranged to, upon activation, be subjected to a second force (F 2) exerted by a force applicator (21; 121a), being a pressurized fluid, of the second detection conduit arrangement (21; 121) and for moving the valve member to a second position, in which said fluid passage portion is aligned for distribution of fire extinguishing medium to the first fire extinguishing sub-system. i) a first force receiving surface arranged to, upon activation, be subjected to a first force (F 1) exerted by a force applicator (19; 119a), being a pressurized fluid, of the first detection conduit arrangement (19; 119) and for moving the valve member to a first position, in which said fluid passage portion is aligned for distribution of fire extinguishing medium to the second fire extinguishing sub-system, and ii) a second force receiving surface arranged to, upon activation, be subjected to a second force (F 2) exerted by a force applicator (21; 121a), being a pressurized fluid, of the second detection conduit arrangement (21; 121) and for moving the valve member to a second position, in which said fluid passage portion is aligned for distribution of fire extinguishing medium to the first fire extinguishing sub-system.