One of the ways to reduce process safety risks is to use instrumented safety devices. This area falls under process safety and is called Functional Safety. Functional safety depends on the correct functioning of systems and equipment that actively respond to external inputs.
Functional Safety also means that the detection of a dangerous situation leads to the activation of a protective or corrective action that prevents the dangerous situation or reduces the consequences of the situation.
To reduce the process safety risks, there are several layers of protection within Functional Safety:
- A Process Control System (PCS) to control the process
- An operator intervention at the moment of exceeding a limit
- A security system to stop the operation
- An active protection system to limit the consequences
An example of a safety system that prevents a dangerous situation is a high level switch that closes a valve on a tank and prevents overfilling.
Examples of an active protection system are smoke detectors that automatically activate a fire-fighting system and an airbag in the car that is triggered by exceeding a certain delay.
They do not prevent the incident (fire or collision), but they do limit the consequences.
To fulfil a role in Functional Safety, an instrumentation background (knowledge of measurement principles, control and safety systems and knowledge of valves and electrical circuits of pumps) is an absolute plus.