The article is dedicated to determining requirements for safety system response time. The safety system response time must be shorter than the process safety time so that the protection system can function efficiently.
Notably, the process safety time is considered a period between a system failure and the occurrence of a hazardous event, which is an important criterion for the safe process system design. This time is unique for each system and for the «cause — consequence» pair and must be determined to ensure the efficient operation of Automated Emergency Protection Systems.
Examples of similar analytical assessments of the process safety time for tube furnace coil overheating, tank overfilling, and pressure rise to critical values in the reactor are considered. Methods that help extend the process safety time in the case of a rapid growth of furnace coil wall temperature have been analyzed, i.e., changing the thickness of the coil wall, and the choice of more fire-resistant materials.
A conclusion regarding the importance of the process safety time for the safety system design has been made. Establishing requirements for the safety system response time based on the process safety time helps optimize algorithms and the performance of protection system activation in order to comply with safety standards. In case the response time cannot be reduced, the adoption of changes in the design will help extend the process safety time, which allows for finding efficient solutions for the safety system functioning.
2. GOST R 51901.1—2002. Risk management. Risk analysis of technological systems. Available at: https://docs.cntd.ru/document/1200030153 (accessed: May 30, 2025). (In Russ.).
3. GOST R 51901.5—2005. Risk management. Guide for application of analysis techniques for dependability. Available at: https://docs.cntd.ru/document/1200041156 (accessed: May 30, 2025). (In Russ.).
4. GOST R MEK 61508-1—2012. Functional safety of electrical, electronic, programmable electronic safety-related systems. Part 1. General requirements. Available at: https://docs.cntd.ru/document/1200103191 (accessed: May 30, 2025). (In Russ.).
5. GOST R MEK 61511-1—2018. Functional safety. Safety instrumented systems for the process industry sector. Part 1. Terms, definitions, and technical requirements. Available at: https://docs.cntd.ru/document/1200160087 (accessed: May 30, 2025). (In Russ.).
6. GOST R MEK 61511-2—2018. Functional safety. Safety instrumented systems for the process industry sector. Part 2. Guidelines for the application of IEC 61511-1. Available at: https://docs.cntd.ru/document/1200160463 (accessed: May 30, 2025). (In Russ.).
7. GOST R MEK 61511-3—2018. Functional safety. Safety instrumented systems for the process industry sector. Part 3. Guidelines for the determination of the required safety integrity levels. Available at: https://docs.cntd.ru/document/1200160132 (accessed: May 30, 2025). (In Russ.).
8. Macdonald D. Practical HAZOPs, Trips and Alarms. Available at: https://www.idc-online.com/downloads/HO_IDCbookextract.pdf (accessed: May 30, 2025).
9. On approval of the Federal norms and rules for industrial safety «General rules of explosion safety for explosive chemical, petrochemical and oil-refining industries»: the Order of Rostechnadzor of December 15, 2020 № 533. Available at: https://docs.cntd.ru/document/573200380 (accessed: May 30, 2025). (In Russ.).
10. On approval of the Federal norms and rules for industrial safety «Safety rules of chemically hazardous production facilities»: the Order of Rostechnadzor of December 7, 2020 № 500. Available at: https://docs.cntd.ru/document/573171533 (accessed: May 30, 2025). (In Russ.).
11. Steves C., Todd R., Norton J., Zhang J. Process safety time for fired heaters. Available at: https://nortonengr.com/wp-content/uploads/2021/01/PTQ-Q4-2020-Process-Safety-Time-for-Fired-Heaters.pdf 573171533 (accessed: May 30, 2025).
12. Towler G., Sinnott R. Chemical Engineering Design: Principles, Practice and Economics of Plant and Process Design. Available at: https://www.academia.edu/37151834/Chemical_Engineering_Design_Principles_Practice_and_Economics_of_Plant_and_Process_Design (accessed: May 30, 2025).
13. API RP 530: Recommended Practice for Calculation of Heater-Tube Thickness in Petroleum Refineries. Washington: API, 1996. 127 p.
14 Pavlov K.F., Romankov P.G., Noskov A.A. Examples and problems for the course of chemical technology processes and devices: higher school student manual. 10-e izd., pererab. i dop. Leningrad: Khimiya, 1987. 576 р. (In Russ).