Steam property reference states

The American Society of Mechanical Engineers (ASME) establishes the following reference states:

• Triple point

  Triple point of water is at 273.16 K or 0.01 °C or 32.018 °F.

• Celsius scale

  The Celsius temperature is exactly Tk - 273.15.

• Critical point

  Critical point of steam is at 647.096 K and 22,064 KPa, or 705.103 °F and 3200.1 psia.

• Reference state

  The specific internal energy and specific entropy of the liquid phase were fixed at zero at the triple point of water