27 Dec Case Study: Improving Safety Systems in an existing chemical manufacturing facility
Client recognizes the need to replace an existing Emergency Shutdown System with a Safety Instrumented System (SIS), the current ‘best practice’ for safety management.
Safety is the paramount concern for chemical, refining and other manufacturing plants. These plants produce materials that are useful, necessary, and important in our everyday lives. SIS solutions are mandatory requirements to provide Safety and Stability when operating these complex facilities. Some existing units at a local chemicals plant were using a Quadlog ESD System which is becoming dated, thus creating the need to upgrade their system.
The basis of SIS engineering is monitoring, controlling, and responding to hazards inherent during operations of process units. First, the potential hazards must be identified, magnitude of failure determined, likelihood of occurrence assessed, existing protections identified, and any remaining gaps in those protections addressed to ensure a desired risk-reduction for the hazard. This process begins with a Hazard and Operability Study (HAZOP) and periodically evaluated in Layers of Protection Analysis (LOPA).
Once all potential hazards for process units have been evaluated and gaps are identified, the owner/operators must decide which gaps warrant follow up actions based on codes, regulations, and insurance guidelines. Safety Instrumented Systems (SIS) engineering is based on IEC 61508 and IEC 61511 codes. These regulations provide guidance and standardization for the design of SIS. SIS is comprised of engineered hardware and software controls that meet the requirements outlined in the above standards and are tested for reliability. The intent of SIS is to provide functional safety designed to ensure the safe response to predefined hazardous operating conditions when necessary to prevent or mitigate the hazardous condition.
An Alternative was chosen to make it happen
Chemic was engaged to provide the detailed engineered package to upgrade their safety system by specification and installation of a new Emerson DeltaV Safety Instrumented System (SIS), including removal of the existing ESD equipment.
Safety, Reliability, Sustainability and Longevity
According to IEC 61508 and IEC 61511, upgrading to SIS will increase the reliability and safety of the control system. It provides an additional layer of protection to the process control system. It reduces the risk hazards for the individuals, environment and equipment.
Chemic has a team of SIS experts and our team was able to help this chemicals plant achieve their goal to reduce the number of failures, and consequently, reduce shutdowns and operational risks. This will increase the operational availability and minimize variability with direct impact to safety and profitability.