The Guiding Opinions of the State Administration of Work Safety on Strengthening the Management of Chemical Safety Instrumentation System (No.14) requires that the safety instrumentation system be independent of the process control system (such as distributed control system). ) and is in a dormant or quiescent state during normal production.

Once a production device or facility has a situation that may lead to a safety accident, it can immediately and accurately act to make the production process stop running safely or automatically enter a predetermined safety state.

Extended data

Characteristics of safety instrument system:

1 Based on IEC6 1508, it conforms to the instrument safety standards stipulated by the International Safety Association.

2. It has wide coverage, high safety, self-diagnosis function and can find and prevent potential dangers.

3. For fault-tolerant multi-redundant systems, SIS generally adopts multi-redundant structure to improve the hardware fault margin of the system, and a single fault will not lead to the loss of SIS safety function.

4. The application program is easy to modify, and the software can be modified according to actual needs.

5. Self-diagnosis coverage is large, and workers need to check fewer points during maintenance.

6. The reaction speed is fast. The response time from input change to output change is generally around 10-50ms, and the response time of some small SIS is shorter.

7. It can realize the safety design of the whole loop from the sensor to the actuator, and has the monitoring function of I/O short circuit and disconnection.

References:

Baidu Encyclopedia-Safety Instrument System