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

Boyle's Law (Mariotte's Law)

The volume of an ideal gas vs. pressure.

Sponsored Links

Boyle's law (Mariotte's Law) states that in a perfect gas where mass and temperature are kept constant - the volume of the gas varies inversely with the absolute pressure.

Boyle's law can be expressed as

PV = constant                                   (1)

or

P 1 V 1 = P 2 V 2 (1b)

or

P 1 / P 2 = V 2 / V 1 (1c)

where

P = absolute pressure (Pa, psi...)

V = volume (m 3 , ft 3 ...)

Example - Final Pressure when Compressing an Air Volume

A gas with volume 1 m 3 and initial pressure 2 MPa is compressed to final volume 0.5 m 3 . With constant temperature the required final pressure can be calculated as

P 2 = P 1 V 1 / V 2

= (2 MPa) (1 m 3 ) / (0.5 m 3 )

= 4 MPa

Example - Final Volume when Compressed Air is Expanded to Standard Conditions

Air is compressed to 114.7 psia in a 4 inches schedule 40 steel pipe . Inside diameter of the pipe is 4.03 inches and the compressed air volume in one foot of the pipe can be calculated as:

V 1 = π (((4.03 in) / (12 in/ft)) / 2) 2 (1 ft)

= 0.09 ft 3

Expansion of the compressed air to a normal pressure of 14.7 psia can be calculated by rearranging Boyle's law:

V 2 = P 1 V 1 / P 2

= (114.7 psia) (0.09 ft 3 ) /  (14.7 psia)

= 0.7 ft 3

Sponsored Links

Related Topics

Related Documents

Sponsored Links

Search

Search is the most efficient way to navigate the Engineering ToolBox.

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 older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

Citation

This page can be cited as

  • The Engineering ToolBox (2009). Boyle's Law (Mariotte's Law). [online] Available at: https://www.engineeringtoolbox.com/boyles-law-d_1276.html [Accessed Day Month Year].

Modify the access date according your visit.

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!

Unit Converter

















































2.19.10

Sponsored Links
.