Logic Solver for Tank Overfill Protection

Introduction A growing level of attention has recently been given to the automated control of potentially hazardous processes such as the overpressure or containment of dangerous substances. Several independent protection methods provide measures to reduce the risk from such hazards to personnel, the environment and assets. A significant level of this risk reduction is allocated to safety instrumented functions (SIF). The integrity of the safety instrumented system (SIS) to perform these functions (known as functional safety) is therefore critical and the requirements for determining and achieving functional safety are given in IEC 61511-1[REF 1]. This standard is now adopted as the predominant worldwide standard for such systems in the process industry.