Compressed fluid
（重定向自Pressurized gas）
![A p-v diagram for liquid water. The compressed fluid region is located to the left of the blue line (the liquid-vapor phase boundary).](/Images/godic/202502/04/P-v_plot3903.png")
A compressed fluid (also called a compressed or unsaturated liquid, subcooled fluid or liquid) is a fluid under mechanical and/or thermodynamic conditions that force it to be a liquid.
At a given pressure, a fluid is a compressed fluid if it at a temperature lower than the saturation temperature. This is the case, for example, for liquid water at atmospheric pressure and room temperature. In a plot that compares pressure and specific volume (commonly called a p-v diagram), compressed fluid is the state to the left of the saturation curve.