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  Notes:
    
    Values for target external furnace wall temperature given in the table are for the mean temperature on the external wall (excluding specific parts) of a furnace during routine operation at an outside air temperature of 20°C.Values for target external furnace wall temperature shall not apply to the furnace wall temperatures of the following furnaces; provided, however, that consideration shall be given to increasing the insulation efficiency of the furnace wall based on the table where possible.
     
      (1) Furnaces with a rated capacity (burner fuel combustion performance) of under 20 L per hour (crude oil equivalent)(2) Furnaces forcibly cooled(3) Rotary kilns(4) Furnaces used for development, research or trial production. |