Emerson has introduced the first valve assemblies that meet the design process requirements of Safety Integrity Level (SIL) 3 as per the International Electrotechnical Commission’s IEC 61508 standard.
Fisher Digital Isolation final element solutions are designed for shutdown valves in critical safety instrumented system (SIS) applications. They are SIL-certified as full assemblies by product certification company exida and can improve critical performance specifications in safety instrumented systems by up to 50%.
Without this solution, users must specify all the individual valve components, procure each one, and assemble them into a working whole. Even if these steps are done correctly, this type of custom assembly will still not provide all the benefits of the Digital Isolation assembly.
Engineering a safety shutdown valve is complicated and the normal and upset process conditions must be carefully evaluated when choosing valve and actuator components. In addition, the proper combination of solenoids, brackets, couplings and other critical hardware must be specified and carefully matched to the selected valve. Each of these components must function individually and with the others.
Emerson addresses this by providing an engineered Digital Isolation shutdown valve assembly, designed for each particular process. The entire assembly is sold as a fully tested and certified unit, with a single serial number and associated documentation delineating the details of every part of the assembly.