Hot runner system, in particular hot runner nozzle for an injection molding machine or plastics injection mold

A hot runner system, comprising:

• a central heating rod having opposite ends;
• a sleeve assembly enclosing the rod and split radially to define first and second sleeves abutting one another, wherein one of the opposite ends of the rod is electrically connected to a free end of the first sleeve and the other one of the opposite ends of the rod is electrically connected to a free end of the second sleeve, said second sleeve having another end distant to the free end thereof and formed with a flange;
• a casing flange surrounding and electric insulating the first sleeve, said casing flange having one end face materially joined with an end face of the flange of the second sleeve wherein the casing flange and the flange of the second sleeve define at least one common flow passageway bounded by a wall surface made entirely of metal;
• and
• current-conducting means for feeding an electric current to the sleeve assembly.