Using Smart Field Devices To Improve Safety System PerformanceSource: International Society of Automation | 11 February 2014
Safety monitoring software can use data from smart field devices to improve safety system performance and operation.
- Many process plants have smart sensors, instruments, and valves installed as part of their safety systems.
- These smart field devices can provide a host of useful information to the safety system.
- Safety monitoring software helps make sense of the information from smart field devices by turning their raw data into actionable information.
Any process plant that handles products, feedstock, or fuels that are the least bit hazardous (flammable, toxic, or otherwise environmentally dangerous) has safety concerns. Operating in compliance with regulations and standards is a way of life for oil, gas, petrochemical, biofuel, and many commodity chemical producers. But beyond compliance, companies want and need to protect their people, equipment, and the surrounding environment.
Applicable standards include ANSI/ISA-84.00.01-2004 Parts 1–3 (IEC 61511 Mod) and IEC 61508, along with facility-recognized best procedures and practices. Compliance with these standards ensures that the plant is not simply within the letter of the law; it helps the plant operate with minimal potential for incidents and injuries.
Undertaking this effort begins with plant hazard and operability studies and the layer of protection analysis (LOPA) methodology. Some situations may call for a quantitative risk analysis, as provided by the Center for Chemical Process Safety and indicated by ANSI/ISA-84.00.01-2004 Part 3, Appendix F.
Performing a LOPA helps identify which identified hazards require safety instrumented functions (SIFs) and the required probability of failure on demand for each to lower the risk to a tolerable level. Performing a LOPA is a main step toward ensuring that requirements under ANSI/ISA-84.00.01-2004 Parts 1–3 (IEC 61511 Mod) are met.
Once the safety instrumented system (SIS) is designed and implemented according to the safety requirement specification, its operation must be maintained and monitored to ensure integrity of the SIF and to ensure ongoing compliance with standards. Any changes to the hardware, such as new equipment, new field devices, different products, or different specified operations and processes must be taken into account using a management of change procedure. Any malfunctions or other process issues must also be accounted for, typically by proof testing and monitoring the SIS along with its associated field devices, such as sensors, instruments, valves, and logic solvers.