Pipelines, programmable logic controllers, and safety

Most new pipeline facilities are being designed using programmable logic controllers (PLCs) for control systems and many existing facilities are being retrofitted with PLCs. However, many engineers are reluctant to depart from the old methods of designing safety and regulatory systems. This results from either a lack of confidence in the PLC based system or a misunderstanding of the regulations concerning these systems. Careful design using PLCs can, in fact, increase safety system reliability and satisfy regulatory requirements