READINGS
Bentley Systems, Incorporated. OpenPlant Power PID. http://www.bentley.com (accessed Aug 2012).
Brawn, R.; CH2M HILL; Nabavian, D; Bechtel. Common Design Workflow Checklist; Element 2 Design Team. http://fiatech.org/images/stories/techprojects/project_deliverables/autodesign_commondesignworkflowchecklist.pdf (accessed March 2013).
Hordeski, M. (2000) Control and Instrumentation Technology in HVAC: PCs and Environmental Controls; Fairmont Press: Lilburn, Georgia.
International Society of Automation (1991) Instrument Loop Diagrams; ANSI/ISA-5.4-1991; International Society of Automation: Research Triangle Park, North Carolina.
Metcalf and Eddy, Inc. (2003) Wastewater Engineering: Treatment Disposal, and Reuse, 4th ed.; McGraw-Hill: New York.
Smart Plant P&ID. http://www.intergraph.com (accessed Aug 2012).
Vantage Plant Engineering by Aveva. http://www.aveva.com (accessed Aug 2012).
Chapter 5
Process Control Narratives
Jeff Coulson, P. Eng, PMP
Jack Geisenhoff, P.E., PMP
1.0 PURPOSE OF PROCESS CONTROL NARRATIVES
2.0 TYPICAL PROCESS CONTROL NARRATIVE COMPONENTS
2.2 Process and Instrumentation Diagrams
2.5.2 Motor Control Center Functions
2.5.5 Remote Automatic Controls
2.8 Performance Reporting Data
3.0 OTHER METHODS OF CONVEYING PROCESS DESCRIPTIONS
3.3 Interactive Process Models
4.0 DEVELOPMENT, UPDATES, AND PRESENTATION
4.1 Document Development and Updates
4.2 Document Storage and Presentation
1.0 PURPOSE OF PROCESS CONTROL NARRATIVES
Process control narratives (PCNs) are written for a number of reasons. They reveal the design engineer’s overall control philosophy and objectives. Process control narratives simply and clearly state how automation systems, including field controllers, human–machine interfaces (HMIs), and reporting and performance management systems, are expected to function. This ensures that suppliers, contractors, and programmers can implement the automation system to meet the objectives of the process. The PCN also serves as a reference and training document for operators and a facility.
A coherent PCN helps coordinate the various disciplines involved in design. It enables process, electrical, and instrumentation and controls (I&C) engineers to work together effectively. Periodically reviewing PCNs with each discipline will significantly improve design coordination.
Process control narratives help the construction team understand the intent of contract documents. They should make the requirements clear to the client, general contractor, I&C subcontractor, electrical subcontractor, and related suppliers. To encourage these parties to read descriptions during the bidding process, the engineer should refer to them as related documents in Part 1 (“general”) of each appropriate Construction Specifications Institute specification.
Process control narratives also provide an operational framework for operations and management staff before, during, and after construction and once the automation system is in service. The narratives should detail how the processes are supposed to work. They can also be used as an operator training and maintenance tool as part of operations and maintenance manuals.
Finally, PCNs are a source of institutional knowledge, which can be particularly important at water resource recovery facilities (WRRFs) where staff members familiar with design and operations are no longer employed at the facility. Indeed, a set of well-prepared PCNs at these facilities can be invaluable. Process control narratives represent the one place where all the interactions among various facility components are documented and explained.
2.0 TYPICAL PROCESS CONTROL NARRATIVE COMPONENTS
