Holdup Posted on 15th November 20156th September 2020 by ThePD (The Project Definition) Holdup is a delay that is the fraction of a particular fluid present in an interval of pipe. 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 Operation and tagged 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.