the storing device 9 incorporated in the chamber 2 the last row of pipes is positioned on the wheels 13 next the chambers 1 2 3 are sealed and then evacuated by means of vacuum pipes to a residual pressure of from 10 1 to 10 6 mm hg the metallizing agent disposed within the evaporators 6 is heated by means of the heating elements 7 to a temperature of active evaporation upon heating the metallizing agent to a required temperature the vacuum gates 5 being open the drive 14 of the transporting means 11 is actuated as this happens the pipes 4 positioned on the wheels 13 are rotating as they are concurrently transferred from the chamber 2 to the chamber 1 while passing through the evaporators 6 the pipes 4 are heated and the external surfaces thereof are coated with the evaporating metallizing agent the metallizing agent disposed inside the pipe 4 is heated by the heat off the pipe 4 whereupon it melts down to spread out along the interior surface of the pipe 4 the temperature of the pipes 4 is regulated by means of the baffles 8 after passing through the metallizing chamber 1 the pipes 4 enter the chamber 3 wherein they are removed from the.