Add new SIS system

I took a look; it’s necessary to first conduct a SIL classification and a hazop analysis to determine the instrument rating and the hazard level, after which the design institute will use this information to design the interlock logic. Could you be more specific? Can a design institute perform instrument grading and analysis?

This post was last edited by ssln123 on 2021-1-2 at 15:58. SIL classification and hazop analysis need to be carried out by qualified design firms; only after the SIL level is determined can the design of the SIS system proceed. Ensure a smooth transition between old and new content in terms of design; the initial design drafts need to be carefully reviewed to avoid any omissions. Strictly speaking, all instruments must meet SIL requirements; therefore, it is necessary to verify whether the old ESD field instruments satisfy these requirements. New additions will be implemented as required. It is said that companies can carry out HAZOP analyses on their own, but the results are usually not professional; therefore, it is better to leave such tasks to qualified design firms. However, after 3 years, companies can conduct these analyses by themselves.

Dongming? The drawings must be obtained from the design institute. Use Hazop and risk grading as needed.

HAZOP analysis at SIL2 level is mandatory; the hydrogenation process involves significant risks, and both the reactor and the heating furnaces used in it are subjects to strict supervision. It is necessary to conduct analysis and determine the risk level first, before proceeding with design and installation. HAZOP analysis must be repeated after any major technical modifications or overhauls, especially when there are changes in important process parameters. Even in the absence of such changes, the analysis should be carried out annually

HAZOP, SIL classification, SIS design and design review, SIL verification, SIS installation, plant acceptance. On-site acceptance: final review of PSSR SIS

It is recommended that HAZOP analysis, SIL assessment, and SIL verification be carried out by qualified institutions; ordinary design firms are generally not capable of doing this, especially when it involves critical hazardous chemical processes.

It is not proprietary to DuPont. This is required by IEC61508

I’m not sure what ESD system you are using; please check whether your ESD device has a SIL certificate. If it does, then no replacement is necessary. Check whether the on-site instruments have SIL certificates; replace those that do not. Ultimately, which circuits should be included in the SIS depends on the SIL classification. The SIL rating should be kept as low as possible; SIL3 should be avoided whenever possible. If SIL3 is initially assigned, various departments should discuss whether other protection layers can be reduced to SIL2. In our company, only one circuit in the hydrogenation reaction process has a SIL3 rating. Given the stringent regulatory requirements and high demands regarding software and hardware configuration associated with SIL3, it was decided to divide this protection layer into two: one is integrated into a SIS system with a SIL2 rating, while the other is controlled through a hardwired circuit using safety relays. Of course, this second circuit is equipped with its own separate sensors and control valves, giving it a SIL1 rating.

First, a HAZOP report is required; based on that report, a LOPA classification is carried out to determine the required SIF level； Second, determine the Safety Instrumented Level of the existing ESD system. Since I have designed projects for which the existing ESD system can meet the requirements, I will check whether it fulfills the LOPA classification criteria. If the SIL level of the ESD system is much higher than what is required for the SIF circuits, it may not be necessary to replace it with a SIS system ； Third, based on the LOPA classification report, the design institute shall modify the PID and complete the entire design work for the automation upgrade ； Fourth, complete the security requirements specification ； Fifth, conduct SIL verification based on the safety level certificates of the instruments and systems actually purchased ； Sixth, during actual debugging and operation, there is also a operation verification report (the name may not be correct; I’ve seen it used in some projects) ； The aforementioned HAZOP, LOPA, as well as various design and verification reports all need to be prepared by entities with the appropriate qualifications. These are the general steps involved in our actual design process; they may not be exhaustive, but they can serve as a reference.