The industrial process industry is experiencing a dynamic growth in Functional Process Safety applications.
At one point, the thought of a safety system conjured up images of Triple Modular Redundant (TMR) systems that represented enormous capital expenses. However today, manufacturers offer a wide gamut of safety-certified devices that can be integrated into very cost-effective solutions. One simple, economical, yet highly dependable option is using a Safety Trip Alarm as a Single Loop Logic Solver.
A Single Loop Logic Solver (or Safety Trip Alarm) monitors a temperature, pressure, level, flow, position, or status variable. If the input exceeds a selected high or low trip point, one or multiple relay outputs warn of unwanted process conditions, provide emergency shutdown, or offer on/off control, such as in a level control application.
Key Advantages of Single Loop Logic Solvers:
- Extensive Features: Programmable inputs, local configuration, safe password protection, process display, transmitter excitation, and comprehensive input and sensor diagnostics.
- Input/Instrument Diagnostics with Fault Alarm: Continuous self-monitoring, continuous input monitoring, and fault detection capabilities for internal and external faults.
- SIL 2 and SIL 3 Applications: Cost-effective solution for SIL 2 and SIL 3 applications without the need for much larger, costly, and complex Safety PLCs.
Examples of Use Cases for Single-Loop Logic Solvers in SIS applications:
• Shutdown in a Hazardous Chemical Process Plant
• Open a Valve to Relieve Excess Pressure
• On/Off Control to Prevent Tank Overflow
• Shutdown Fuel Supply to a Furnace
• Add Coolant to Arrest Exothermic Runaway
• Automatic Shutdown When Operator Not Present
• Close a Feed Valve to Prevent Tank Overflow
• Initiate Release of a Fire Suppressant
• Initiate an Evacuation Alarm
By leveraging Single Loop Logic Solvers, users can often achieve the same advantages as larger and more expensive safety-certified PLCs at a fraction of the cost. This makes it an ideal solution for meeting IEC 61511 standards efficiently and economically.
