Analyzing, tracking process hazards
Regulatory compliance is driving industry to provide more complete information concerning its manufacturing processes and systems partially because many process industries either use hazardous feedstock or produce hazardous materials. To ensure safe operation of these facilities, OSHA Process Safety Management (PSM) rules (29 CFR 1910.
Regulatory compliance is driving industry to provide more complete information concerning its manufacturing processes and systems partially because many process industries either use hazardous feedstock or produce hazardous materials. To ensure safe operation of these facilities, OSHA Process Safety Management (PSM) rules (29 CFR 1910.119) mandate documentation of the process and its associated control system design.
It is vital that the control development team be an integral part of a PSM documentation effort, recording how the control system manages a process and the failure modes of the system. All possible control failure schemes must be considered as part of the completed project—a difficult task at best. Therefore, control system plans need to be part of the initial Process Hazard Analysis (PHA) in addition to being implemented and maintained under Management of Change (MOC) program for the process.
Additional help available
To assist, hazard analysis guidelines are available from the American Institute of Chemical Engineers Center for Chemical Process Safety (New York, N.Y.). However, to augment these existing resources, Dyadem International Ltd. (Markham, Ontario, Canada) has developed PHA-Pro 5, a software package designed to support Process Hazard Analysis, capturing all required process and control system data. Areas tracked in the software include:
PHA team members and their attendance at PHA sessions;
Process units and their functions;
Safety and environmental hazards associated with each unit, including hazard severity;
Installation, operation, and maintainability issues for all control systems;
PHA recommendations for safety improvement;
All piping and instrumentation drawings (P&IDs); and,
The program supports all common types of PHA methodologies and comes with basic question libraries for "What if" and Hazard and Operability studies. In addition, these libraries can be edited to create a site-specific template for analysis. This is particularly useful for creating a custom node template for the control system that is in generic form and not addressed in the MOC library.
Another valuable feature for the individual responsible for maintaining the control system is the ability to integrate PHA and MOC activities into one database. A single database places the history of control system decisions in the same tracking environment for implementing changes. Thus, even when original team members are unavailable, the logic behind all control system design decisions and revisions is available in a central location. Because analysis of a process to meet OSHA regulations typically requires several meetings, and a considerable time investment, process developers can use this custom database application to protect against data loss, guarding against the need for data reentry or repeating earlier investigative meetings.
Because the data are also used for MOC analysis, all database information needs to be secure for the life of the process. To prevent loss of data, the PHA-Pro package has multiple levels of protection specifically intended to provide data integrity.
This review is based upon version 188.8.131.52 of the PHA-Pro 5 package, www.dyadem.com.
Contributing Editor, Tracy J. Coates P.E. is a consulting engineer at PCE Engineering, Johnson City, Tenn.
For more information on PHA-Pro 5, circle 345 or go online at www.controleng.com/freeinfo.