A medical product configured for use in a medical system and a method of handling a medical system comprising a first subsystem and a second subsystem containing a medical fluid are provided. A connector connects the first and second subsystems for transport of the medical fluid from one of the subsystems to the other subsystem. The connector comprises a valve device, a first connection pipe connectable to the first subsystem, and a second connection pipe connectable to the second subsystem. The valve device comprises a first part and a second part, which are movable in relation to each other to permit an opening movement from a closed position, preventing a fluid communication between the first and second connection pipes, and an open position permitting the fluid communication. The medical product comprises a blocking member preventing, in a blocking state, the opening movement, and permitting changing of the blocking state to a non-blocking state permitting the opening movement.