The difference and relationship evolution between chemical GDS system and SIS system
The GDS system and the SIS system are systems that chemical companies often encounter, but the industry is relatively chaotic. Some say that GDS is an integral part of the SIS system, and some say that the two are independent of each other. When choosing the GDS system, you will find that the solutions provided by some manufacturers are no different from the SIS system. So what are the differences between the SIS system and the GDS system? AIYI Technologies will answer you in detail this time.
Definition of GDS system and SIS system
GDS system: Gas Detection System, which mainly consists of combustible gas or toxic gas detectors, on-site alarms, alarm control units, etc., used to detect the concentration of flammable gas and toxic gas in the factory, when there is In case of leakage, it can be monitored and alarmed in real time.
SIS system: Safety instrumentation System, sometimes also refers to the Safety interlocking System. It is mainly the alarm and interlocking part of the factory control system, which implements alarm action or adjustment or shutdown control for the detection results in the control system. It is an important part of the factory's automatic control.
The evolution of the relationship between the GDS system and SIS system
Early-inclusive relationship: In the original document No.116 of the State Administration of Work Safety, the chemical instrumented safety system (SIS) includes the GDS system. And in the past GDS system bidding, the product specifications were mostly based on the SIS system, which required high redundancy and must have SIL certification.
Currently-relatively independent: In 2019, the new version of "Petrochemical Combustible Gas and Toxic Gas Detection and Alarm Design Standard" (GBT 50493-2019) issued in 2019 also clarified that the GDS system should be set independently and cannot be connected to other systems.
Safety protection layer function diagram
It can be seen from the figure that the GDS system is to give an alarm after a gas leak, which belongs to the level of disaster reduction, while the emergency stop and other systems of the SIS system are more of the disaster prevention level, and the two do not belong to the same safety protection layer. At the same time, when the SIS system fails, an independent GDS system is required to function.
Does the GDS system require SIL certification?
As we all know, SIL certification is mainly a third-party assessment, verification and certification for evaluating, and confirming the safety integrity level (SIL) or performance level (PL) of safety equipment.
Unlike the SIS system, the GDS system does not have safety instrument function requirements. The reliability of the system can be met by using high-quality electronic products or necessary redundancy. There is no need for safety and reliability design. Therefore, the GDS system does not require SIL certification.
GDS system related product information
AEGDS200GDS system function
Alarm reminder: Real-time display of the current status of the detector, display of gas concentration and sound and light alarm.
Electronic map: The system establishes an "electronic map" of the field equipment of the device according to the actual installation location, which contains the location information of each field equipment. When the field equipment issues an alarm, the whole factory monitoring screen displays an alarm, and the partition screen displays the alarm. The specific location of the point.
Alarm information: Has a history record function, used to record system and field detector failure and alarm information.
Power failure protection: UPS power supply is configured to ensure the normal operation of the system when the power supply is suddenly disconnected.
Operation authority: The system has the function of operation authority. Different authority is set for different levels of roles to prevent the system from malfunctioning due to random operation.