Process Safety and Safe Automation

This chapter discusses how the process equipment for chemicals can be designed using inherently safer strategies to assure safe operation under foreseen process upsets, such as specifying design limits above the maximum and minimum operating parameters that exist under emergency conditions. Inherently safer design involves making conscious choices to design and operate the process in a manner that avoids the hazard or minimizes the likelihood and consequence of the loss events. Inherently safer practices can create safeguards that have less potential for dangerous failure, whether the failure occurs due to safeguard design, to a support system disruption or to human error. Once the process design is complete, the risk of process operation generally can be further reduced through the implementation safeguards. These safeguards are implemented in protection layers. The need for functional safety management is determined by analyzing how abnormal operation propagates to loss events. Protection layers can reduce risk to an acceptable level but these functional safety features can be impacted by human error during the equipment life starting with conceptual design and ending with equipment replacement.