DKEC has R&D, engineering design and equipment manufacture bases in New York, Shanghai and Wuxi. We are an international engineering company, offering consulting services, process package Know-how transfer, engineering design, and EPC services in chemical and environmental industries.
Safety Integrity Level,SIL Grading and Checking

Besides HAZOP study, we also deploy a range of tools to analyze Functional Safety defined by IEC standard 61508, making Safety Integrity Level(SIL) verification about electronic and instrumented systems.

There are four SIL levels-SIL 1, SIL2, SIL3 and SIL 4. The higher the SIL level, the greater the risk of system failure, which requires stricter safety requirements. The following table is comparison of SIL level and other standards.

With abundant knowledge and experience in evaluating functional safety, our SIL experts analyze and determine SIL level of whole Safety Instrumented Functions(SIFs) for new plants, during basic engineering design period.

We also make SIL assessments and verification about existing facilities. Our clients trust DKEC to provide these safety solutions because we have in-depth knowledge of whole Safety Lifecycle and offer experienced support to ensure the compliance with international standards such as IEC 61511 and IEC 61508.

1.What are HAZOP requirements regulated in China?
According to the "General Administration of Work Safety of the State Administration of Work Safety [2014] No. 116-Guiding Opinions on Strengthening the Management of Chemical Safety Instrumented Systems": From January 1, 2018, all new chemical plants involving "two important points and one major" will be newly built And hazardous chemical storage facilities should be designed with safety instrumented systems that meet the requirements. For other newly-built chemical installations and hazardous chemical storage facilities safety instrumented systems, from January 1, 2020, relevant functional safety standards and requirements shall be implemented, and safety instrumented systems that meet the requirements shall be designed. Chemical companies and hazardous chemical storage units involving "two key points and one major" in-service production plants or facilities must conduct a comprehensive process hazard analysis (such as hazard and operability analysis HAZOP) and determine the safety instrument function through risk analysis And its risk reduction requirements (ie: safety integrity level SIL rating), and as soon as possible to assess whether the existing safety instrument functions meet the risk reduction requirements (ie: SIL verification).
2. How long does a SIL assessments and verification take?
Collect production-related information on safety, technology, equipment, control, operation and other aspects in the early stage, and then organize experts in safety, technology, equipment, control, and operation to analyze and discuss, and finally compile SIL grading and check calculation reports.
The time it takes is closely related to the scale of the production device and the level of complexity of the process, and it generally takes 20 to 30 working days.
3.What information must be gathered in preparation for a SIL assessments and verification?
SIL grading requires data collection:
(1) Safety assessment and environmental assessment report
(2) Summary table of HAZOP analysis recommendations
(3) Process flow and control instructions, operating staff work flow and distribution
SIL verification needs to collect data:
(1) SIL rating report
(2) SIS system safety function requirement specification (SRS)
(3) SIF circuit interlocking logic diagram
(4) SIS system SIL grade specification; SIL grade specification of each purchased instrument.
4.What projects are applicable to SIL grading and verification?
According to the relevant laws and regulations of the State Administration of Work Safety, chemical companies and hazardous chemical storage units that have newly built or in-service production plants or facilities related to the “two key points and one major” must use the SIS system, which means they all need to be SIL rated. And SIL checking. Moreover, the SIS system must be controlled throughout its life cycle, that is, SIL rating and verification must be done again in three to four years.
["Two important points and one major" refers to: the hazardous chemical processes under key supervision, the hazardous chemicals under key supervision, and the major hazards]
5.What are the benefits of SIL grading and verification for enterprises?
In terms of safety, SIL grading and SIL checking can improve the safety production level of enterprises and ensure safe production; in terms of technology and cost, SIL grading and SIL checking can grade each individual instrument to make it suitable for the enterprise In this way, companies can avoid over-purchasing high-SIL-level SIS instruments and SIS systems, making the best use of their materials, and at the same time, reducing corporate procurement costs. Especially now that many places have implemented safety production licenses, HAZOP analysis, SIL grading and SIL checking calculation reports must be provided, and SIL grading and SIL checking calculations have become mandatory requirements.