For series-produced fans, often taken from stock, it is not always possible to define the duty. In such cases, reference should be made to the source of applicable performance data.For all fans supplied without driving motors, the maximum safe operating speed and gas temperature should be given on the nameplate.B.2 The following additional information may be provided:a) year of manufacture;b) mass in kilograms (kg);c) maximum operating temperature, tmax, in degrees Celsius (°C);d) maximum rotational speed, nmax, in revolutions per second (r/s);e) maximum power, Pmax, in kilowatts (kW).