Critical Pressure Posted on 6th November 201523rd July 2021 by ThePD (The Project Definition) Critical Pressure is the minimum pressure that is the pressure required to liquefy a gas at its critical temperature. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Engineering and tagged pressure, process. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.