National Grid has over 500 high pressure gas sites on the National Transmission System (NTS) which require accurate Piping and Instrumentation Diagrams/Drawings (P&IDs). There is an opportunity to improve the accuracy of these P&IDs to drive efficient and effective maintenance activities and capital projects.
Benefits
The annual costs of maintaining the existing P&ID drawing suite are approximately £100k. Creating P&IDs from 3D models is expected to reduce these costs significantly, improve the overall accuracy levels of the drawings and reduce the number of inaccurate or missing drawings.
Where unexpected issues occur due to inaccurate drawings on large projects, there can be additional costs such as resurvey work, rework of project plans and compensation. Additional costs incurred on a recent NGGT project resulted in an increase of £500k in project costs. The frequency of this type of event is expected to decrease through improvements in the accuracy of the drawing suite and increased confidence in the data contained within the drawings.
The development of a mechanism to compare the accuracy of data within 3D models, P&IDs and the Ellipse database will enable improvements in the consistency of records and increase confidence in asset management decision making.
Greater accuracy in the drawing suite is expected to reduce risk and improve safety on site due to the correct identification of process equipment and true representation of the process plant e.g. complete network of pipes and equipment components, essential for equipment planning and maintenance activities.
