Is it on or off the SIS system?
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It was found through communication that many CNG plants do not have SIS, while all LNG plants do have SIS. Is the use of a Safety Instrumented System (SIS) related to the hazard level of the installation? Chapter 10 of the \"Design Code for Liquefied Natural Gas Plants\" GB51261-2019 directly specifies the requirements for SIS; does this mean that SIS is necessary in all cases, regardless of the hazard level?
Currently, it is based on safety risk assessments (HAZOP, LAPO analyses), followed by the determination of the SIL level; for those that require a specific safety level, the design institute is responsible for determining the SIL value. In fact, safety-related laws and regulations were established as early as 2012, but their implementation within the industry, as well as in design processes, is still being improved over time
There are 4 SIL levels; having a value within this range means there is a safety level, and then an SIS is required – is that what it means?
Should SIS be installed? 1. Regulatory requirement: As of January 1, 2018, all newly built chemical processing units and hazardous chemical storage facilities that fall under the category of “two key areas and one major hazard” must have safety instrument systems designed in accordance with relevant standards. For the safety instrument systems of other newly built chemical processing units and hazardous chemical storage facilities, starting from January 1, 2020, the requirements of functional safety standards must be complied with, and safety instrument systems that meet these requirements shall be designed ； The in-service unit shall complete the assessment and improvement of its safety instrumented system by the end of 2019. According to the calculations carried out by safety experts regarding the volume of CNG storage tanks, if a site qualifies as a major hazard source, a 2.HAZOP analysis is required; in cases where the consequences of an accident could be severe (in terms of casualties and property damage), such an analysis is highly recommended. 3. Regarding the requirements for operational safety, decisions on whether to implement it are made strictly in accordance with the results of HAZOP analysis
Generally, a rating is required. It is mandatory to meet the requirements. The tank farm and main production units must be included.
Bro, have your company find a qualified design firm to do the calculations for you and conduct a proper evaluation; only after that can it be determined whether it’s necessary for you to implement SIS. It’s not up to you or the experts to decide – there are theoretical foundations behind this
The design unit does not have the authority to decide whether something qualifies for inclusion in the SIS; this is stipulated by the design standards and legal regulations. Few design institutes these days can accurately edit the logical relationships in interlock logic diagrams.
All newly constructed chemical plants and hazardous chemicals storage facilities involving the \"two key areas and one major issue\" must be designed with safety instrument systems that meet the required standards. If you need third-party assistance, feel free to contact me.