FIELDVUE Instruments
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Processes that involve toxic or highly flammable fluids typically rely upon safety instrumented systems (SIS) to protect against upsets or failures that might threaten worker safety, cause environmental concerns, or damage operating equipment.
A safety instrumented system typically consists of sensors to monitor the process, logic devices that compare process conditions to predetermined process limits, and final control elements that shut down or vent the process should conditions reach a trip point.
Will the Shutdown Valve Work?
All SIS components must work on demand to ensure that the system operates as planned.
The operating integrity of the SIS most often depends upon its final control elements. These valves typically remain in one position until called upon to respond. In fact, they may never be instructed to stroke from a standby position, which means they eventually may become stuck, unable to operate.
If a shutdown valve fails, the safety instrumented system may not be able to take the process to a safe state.