Zhejiang Engineering Design Co., Ltd. is committed to providing clients with distinctive value-added services.

　　This year, in accordance with the new requirements on hazardous chemical safety assessment management issued by the State Administration of Work Safety and the Provincial Administration of Work Safety, Zhejiang Engineering Institute seized the opportunity presented by the large-scale license renewal process among hazardous‑chemical producers. By forging strategic partnerships with relevant organizations, the Institute has vigorously advanced a range of safety‑related services, including Hazard and Operability (HAZOP) analysis, Layer of Protection Analysis (LOPA), Safety Integrity Level (SIL) classification, SIL verification, and Safety Instrumented System (SIS) design. After years of dedicated expertise in the field of safety, the Institute’s management fully recognizes the critical importance of implementing preventive measures during the design phase. In pursuing SIS systems, it has remained steadfast in its commitment to driving progress through reform, thereby opening a gateway of innovation and transformation for chemical enterprises to enhance their production safety management and control.

　　As early as 2011, the State Administration of Work Safety issued Document No. [2011]40, implementing the Interim Provisions on the Supervision and Administration of Major Hazard Sources of Dangerous Chemicals. In response, the management of Zhejiang Engineering Institute promptly took action, carefully studying the document’s contents and identifying the elements relevant to engineering design. Article 13, in particular, mandates the establishment and improvement of a comprehensive safety monitoring and surveillance system, along with the refinement of control measures. It stipulates that chemical production units containing major hazard sources must be equipped with automated control systems that meet occupational safety requirements; first- and second-level major hazard sources must be fitted with emergency shutdown systems; and key facilities handling toxic gases, highly toxic liquids, and flammable gases must be provided with emergency isolation devices. Furthermore, first- and second-level major hazard sources involving toxic gases, liquefied gases, or highly toxic liquids are required to be equipped with independent safety instrumented systems (SIS).

　　At that time, the State Administration of Work Safety had just issued requirements mandating the installation of SIS systems. The industry was only aware of this general direction; specific implementation remained unclear, leaving practitioners at a loss as to how to proceed. From the perspective of intrinsic safety design, the management of Zhejiang Engineering Institute recognized that safe production in chemical enterprises has a profound impact on both people’s livelihoods and daily life. They concluded that deploying a well‑designed SIS is not only a necessary trend for ensuring safe operations but also an essential responsibility for the company to fulfill its social obligations in the realm of industrial safety. Accordingly, beginning in 2011, the institute began building up foundational knowledge in safety instrumented systems. With a spirit of “daring to tackle the deep waters and gnawing at the hardest bones,” they resolved to devote themselves wholeheartedly to researching SIS technology. The project leader vividly recalls that at the time, the Zhejiang Provincial Administration of Work Safety was vigorously promoting SIS‑related management across the province. Upon learning of our research efforts, they offered strong support and dispatched experts to guide us as we embarked on studying SIS systems. The company assigned the Electrical and Instrumentation Department to lead this initiative. Although department head Liu Rilin had no prior experience with SIS, he nonetheless accepted the task without hesitation. With no systematic resources available online and no clear channels for consultation, he relied on his professional expertise and practical experience to gather scattered materials, teaching himself while carefully analyzing them. Working closely with colleagues in the department, he engaged in continuous discussion and exploration, gradually expanding his understanding and progressively constructing a coherent framework.

　　After more than three months of dedicated effort, the first independent SIS system design was successfully completed at Shandong Dongju Phase I, and the system was commissioned on the first attempt. The SIS is the final line of defense in the proactive safety protection layer of chemical production. It reduces the frequency of hazardous incidents or mitigates their consequences, keeping risks within acceptable limits to ensure the safety of personnel, equipment, and the surrounding environment. Through the proper configuration of the SIS, the overall production safety level of chemical enterprises subject to the “Two Key Areas and One Major Hazard” regulatory framework has been substantially enhanced, effectively implementing a critical component of safety supervision and management mandated by both the State Administration of Work Safety and the provincial safety regulatory authorities.

In response to industry needs and as our understanding of SIS systems deepened, we gradually recognized the critical importance of design basis. In 2013, the company decided to adopt and promote HAZOP analysis. The development of SIS‑related business at Zhejiang Engineering Institute has progressed through four stages: In the initial stage, SIS designs were developed without a formal design basis, relying solely on past operational experience or ad hoc decisions. In the second stage, HAZOP workshops brought together stakeholders—including the owner, the technology provider, and our company—along with relevant specialists to collaboratively determine the SIL level of the SIS. In the third stage, LOPA analysis was conducted on the basis of HAZOP, using protection layer analysis of risk scenarios to establish the SIL levels for Safety Instrumented Functions (SIFs), thereby providing data‑driven support for the SIS system. In the fourth stage, in alignment with functional safety management requirements, verification activities were carried out to confirm the target SIL level of the SIS. This verification ensures that the intended SIL level is fully implemented, closing the loop on SIS‑related design work and further guiding both the design process and the procurement of instrumentation and equipment, thus guaranteeing the reliability and availability of the SIS.

　　Through collaborative innovation between the process engineering and automation control disciplines, functional safety management has been refined, end-to-end safety‑management workflows have been streamlined, and the role of functional safety has been fully leveraged. This approach ensures that chemical‑plant safety design is grounded in fundamental principles, thereby comprehensively elevating intrinsic safety levels. After six years of dedicated research, substantial results have emerged. As the requirements of the State Administration of Work Safety have become increasingly stringent, both new and existing clients, compelled by these developments, have proactively sought out the Zhejiang Engineering Institute to undertake SIS‑related analysis, validation, and design work, as well as to implement upgrades to their automated control systems and safety instrumented systems. During follow-up visits with longstanding clients, design engineers, guided by intrinsic‑safety principles, proactively propose feasible recommendations for safety‑system upgrades, enabling these clients to take a leading position in the industry when modernizing their “two key areas and one major hazard” automated control systems and SISs, while also helping them fulfill their primary responsibility for workplace safety.

　　Zhejiang Engineering Institute has consistently adhered to the guiding principle of “delivering high‑quality work, building a strong reputation, and establishing a reputable brand.” While providing exceptional service to its clients, it rigorously implements all safety‑related measures in accordance with the requirements of the State Administration of Work Safety and the provincial safety supervision authorities, thereby achieving tangible improvements in production safety at chemical manufacturing enterprises. As a result, the Institute has earned further recognition from both the provincial safety supervision bureau and existing and new clients, cultivating an excellent reputation and a distinguished brand within the province. Today, Zhejiang Engineering Institute has become a leading force in the region, capable of comprehensively undertaking SIS‑related projects.

　　At the Zhejiang Province Safety Production Teleconference held in August, it was emphasized to “expedite the establishment and improvement of a tiered risk management and control system, supported by technical and engineering solutions as well as intelligent monitoring and control measures.” As Zhejiang Province’s pilot implementation of SIS systems continues to mature, this initiative is expected to be rolled out nationwide in the near future. The Zhejiang Academy of Engineering has already accumulated proven technologies and a track record of successful projects, enabling it to provide domestic hazardous‑chemical enterprises with advanced, tailored process designs, cutting‑edge technologies, state‑of‑the‑art equipment, and automated control systems. This capability ensures frontline intelligence, enhances plant‑wide operational efficiency, and underpins intrinsic safety in economic operations, while laying a solid foundation for leveraging big data to guide production and business decision‑making and jointly advancing the development of smart factories.