Functional safety is the detection of a potentially dangerous condition resulting in the activation of a protective or corrective device or mechanism to prevent hazardous events arising or providing mitigation to reduce the consequence of the hazardous event. Functional safety relies on active system, here is an example:
- The activation of a level switch in a tank containing a flammable liquid, when a potentially dangerous level has been reached, which causes a valve to be closed to prevent further liquid entering the tank and thereby preventing the liquid in the tank from overflowing.
Hazard analysis is an integral part of functional safety. Hazard analysis identifies the level of functional safety necessary if at all to ensure adequate protection against each significant hazard. This information is paramount for the proper system design.
IEC 61508 Standard – Functional safety applies to safety-related systems when one or more of such systems incorporate electrical and/or electronic and/or programmable electronic (E/E/PE) devices. It covers possible hazards caused by failure of the safety functions to be performed by the E/E/PE safety-related systems, as distinct from hazards arising from the E/E/PE equipment itself (for example electric shock etc). It is generically based and applicable to all E/E/PE safety-related systems irrespective of the application.
Electrical and/or electronic and/or programmable electronic (E/E/PE) devices are commonly found in the following process:
- emergency shut-down systems
- fire and gas systems
- guard interlocking and emergency stopping systems for machinery
- variable speed motor drives used to restrict speed as a means of protection
- remote monitoring, operation or programming of a network-enabled process plant
- an information-based decision support tool where erroneous results affect safety
SAFE Engineering employs TUV Rheinland Functional Safety Certified Professional Engineers capable of handling the entire projects were Functional Safety is necessary. Please refer to our article The Future of Equipment Safety