【Safety Management and Standardization of Special Equipment】- Does the Fixed Pressure Vessels Regulation specify specific design service life requirements for pressure vessels?

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Ensure proper safety management of special equipment – Standardization ensures safety! [Special Equipment Safety Management and Standardization] – Comprehensive summary post! Constantly being updated – feel free to communicate! ! ! https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5718553 (Source: Haichuan Chemical Industry Forum (Hua Haichuan Liu hcbbs)). Everyone is welcome to participate in the discussions. --------------------------------------------------------- The “Regulations on Fixed Pressure Vessels” stipulate that design agencies must determine the design service life of pressure vessels, but it does not specify a concrete duration for this service life. Determining the design service life of a container should take into account at least the following 7 factors: selecting appropriate materials and structural design ； Reasonable corrosion margin ； Appropriate manufacturing and inspection requirements ； Possibility of limiting creep or fatigue ； The cost of building containers ； The role of containers in the device ； The operation cycle of the container. The design service life and the actual service life are not the same concept. The design service life is a target value set by the pressure vessel designer; it meets the user’s expectations regarding the use of the pressure vessel. It is not a guarantee, nor can it be considered the time at which the pressure vessel should be retired. Users of pressure vessels shall conduct regular inspections and grading of the vessels in accordance with the requirements of current regulations (Regulations on Pressure Vessels). When the operating conditions of the container change, the corrosion rate should be re-evaluated based on actual measurement data to determine the new service life of the container. Imposing a mandatory design service life is necessary; it helps to improve the design standards for pressure vessels and promote a design approach based on failure modes. It also facilitates the management of pressure vessel use and safety supervision, as well as regular inspections during their operation. According to HG/T 20580, the recommended design service life for the vessels is as follows: For hydrogenation reactors with a chromium-molybdenum steel back wall or a high-alloy steel back wall with a nominal thickness of ≥50 mm, the service life is not less than 30 years. Other reactors, towers with a diameter of ≥4m or a weight of ≥100t or a total height of ≥60m, high-pressure heat exchanger shells, vessels with a nominal thickness of ≥50mm, and spherical storage tanks: not less than 20 years. Other towers, vessels, heat exchanger shells, and tube banks: not less than 15 years. For vessels with periodic variations in operating temperature or pressure, the number of cycles of such temperature or pressure changes during the design life shall be specified in the design drawings.