Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Water vs. Steam - Critical and Triple Points

Critical point is where vapor and liquid are indistinguishable and triple point is where ice, water and vapor coexist in thermodynamic equilibrium.

Sponsored Links

At the critical point there is no change of state when pressure is increased or if heat is added. At the critical point water and steam can't be distinguished and there is no point referring to water or steam.

The critical point of water is achieved at

  • Water vapor pressure of  217.75 atm = 220.64 bar = 22.064 MPa = 3200.1 psi 
  • Temperature of 647.096 K = 373.946 °C = 705.103 °F 
  • Critical point density:  0.322 g/cm3 = 0.6248 slug/ft3 = 20.102 lbm/ft3

For states above the critical point the steam is supercritical. Supercritical is not the same as superheated - which is saturated steam at lower pressures and temperatures heated above the saturation temperature.


The triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.

The triple point of water is at

  • Water vapor pressure of  0.00604 atm = 6.12 mbar = 611.657 Pa = 0.08871 psi
  • Temperature 273.16 K = 0.01 °C = 32.02 °F
  • Triple point density (liquid): 0.99979 g/cm3 = 1.93991 slug/ft3 = 62.4148 lbm/ft3


See Water and Heavy Water - for thermodynamic properties.
See also Water Boiling points at high pressure, Boiling points at vacuum pressure, Density, specific weight and thermal expansion coefficient, Dynamic and kinematic viscosity, Enthalpy and entropy, Heat of vaporization, Ionization Constant, pKw, of normal and heavy water, Melting points at high pressure, Saturation pressure, Specific gravity, Specific heat (heat capacity) and Specific volume for online calculatores, figures and tables showing temperature or pressure dependences of the different properties.

Critical_temperature_pressure

Sponsored Links

Related Topics

Related Documents

Sponsored Links

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!

Translate
About the Engineering ToolBox!

Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.

Citation

This page can be cited as

  • Engineering ToolBox, (2005). Water vs. Steam - Critical and Triple Points. [online] Available at: https://www.engineeringtoolbox.com/critical-point-water-steam-d_834.html [Accessed Day Mo. Year].

Modify access date.

. .

close

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Scientific Online Calculator

Scientific Calculator

3 10

Sponsored Links
.