What considerations should be taken into account when designing containers for extremely hazardous and highly dangerous media?

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Issues to consider in the design of containers for extremely hazardous and highly hazardous media: 1) For containers holding media with extremely high or high toxicity, all welding joints of Category A and Category B shall undergo radiographic testing or ultrasonic testing—GB150.4-2011, Clause 10.3.1e). Welded joints of categories A and B for containers containing highly toxic or extremely hazardous materials must undergo full radiographic testing or ultrasonic testing-----Code for Fixed Containers 3.2.10.2.2.2, P23. Weld joints of pressure vessels containing media with extremely high or high toxicity levels require magnetic particle or penetrant testing on their surfaces. ——Solid volume gauge 3.2.10.2.2.4(1), P24. 2) Cast iron shall not be used for manufacturing the pressure-bearing components of pressure vessels containing media with an extreme, high, or moderate degree of toxicity hazard------ASME Code P10, Section 2.2.3.1 ； Cast steel shall not be used for manufacturing pressure-bearing components of pressure vessels that contain media with an extremely high, high, or moderate degree of toxicity hazard------ASME Code P10, Section 2.2.4.1. Q235B and Q235C shall not be used for media with an extremely high or high degree of toxicity. ——Appendix D P87 in GB150.2-2011. Q235B and Q235C shall not be used for containers holding media with an extremely high or high degree of toxicity. --HG/T20581-2011, Clause 7.2 P62. 3) When carbon steel and low-alloy steel plates with a thickness of 12 mm or more (excluding the plates of multi-layer pressure vessels) are used to manufacture the main pressure-bearing components of pressure vessels, and such plates are used to contain media with an extremely high or high degree of toxicity, they must be subjected to ultrasonic testing one by one, with the qualification grade being no lower than Grade II. ——Fixed Volume Gauge P8 2.2.1.4.1 ； Article 2.2.1.4.2. For pressure vessels whose containing medium is highly toxic and classified as extremely or highly hazardous, the main pressure-bearing components made of ferritic steel plates with a thickness of 20 mm or more shall be subjected to ultrasonic testing on a piece-by-piece basis, with a grade of II being considered acceptable. ——HG/T20581-2011, Clause 6.2.1 for P54. 4) Pressure vessels made of carbon steel and low-alloy steel that contain media with an extremely high toxicity hazard, as well as their pressure-bearing components, shall undergo post-weld heat treatment – ASME Code for Pressure Vessels P25, Section 3.2.11(2). Carbon steel and low-alloy steel vessels used to contain media with extremely high or high toxicity shall undergo post-weld heat treatment—GB150.4-2011, Clause 8.2.2.3. When the medium is classified as extremely hazardous or highly hazardous, post-weld heat treatment is required for carbon steel and low-alloy steel equipment —— HG/T20584-2011, Clause 6.0.3. For cold-formed steel pressure components and containers holding extremely hazardous or highly hazardous media, if the degree of deformation exceeds the specified limits, appropriate heat treatment should be carried out after forming to restore the material’s properties. ----GB150.4-2011, Clause P330 8.1a). 5) For containers equipped with Class A longitudinal welded joints containing media of extremely or highly hazardous toxicity, product welding specimens shall be prepared for each container individually. -----GB150.4-2011, Clause P333 9.1.1.1a). Pressure vessels containing media with extreme or high toxicity hazards shall have product welding test pieces prepared. -----Paragraph 3) of Clause 3.2.4.1 of the Fixed Volume Gauge, P21. 6) For pressure vessel weld joints in which the medium is explosive or has an extremely high or high level of toxicity, a fully penetrative weld structure shall be employed. ——ASME Section P21, 3.2.2.2. When the container is used to hold extremely hazardous or highly toxic substances, fully penetrative welds should be selected. ——HG/E20583-2011 Clause 18.9.2, P489. 7) Pressurized components with a medium toxicity hazard level of extreme, high, or moderate shall not use commercial-grade fasteners. -----HG/T20581-2011 6.6.1 P59. 8) For pressure vessels containing media with extremely high or high toxicity, their pipe flanges shall comply with the provisions of the HG/T20592-HG/T20635 series of standards, and a combination of necked butt-welded flanges, metal wound gaskets with reinforcement rings, and specially graded high-strength bolts shall be used. ----Fixed volume gauge P22, clause 3.2.5(2). For container nozzles with media that are extremely or highly hazardous, necked butt-welded pipe flanges should be used. ——HG/T20583-2011, Clause 7.2.4 P437. For container connections with extreme or high medium toxicity, the nominal pressure class of the flanges should be no less than 2.0 MPa. -----HG/T20583-2011, Clause 7.2.3 P437. 9) For pressure vessels containing explosive media, or media with an extremely high, high, or moderate level of toxicity, ducts shall be installed at the discharge outlets of safety valves or rupture discs to direct the discharged media to a safe location where it can be properly handled; toxic media must not be discharged directly into the atmosphere. ——Fixed volume gauge P96, clause 9.1.2(3). For containers holding extremely hazardous or highly dangerous substances, a conduit should be installed at the outlet of the release device to direct the released material to a safe location where it can be properly disposed of; it must not be discharged directly into the atmosphere. ——GB150.1-2011, Appendix B, Clause B.3.10, P18. 10) For forgings whose medium of use is extremely or highly toxic, they shall meet the requirements of Grade III or Grade IV. ——HG/T20581-2011 (P57) 6.4.3 11) For containers whose storage medium is extremely or highly toxic, manholes with a smaller nominal diameter are preferred – HG/T20583-2011 Article 8.5.4. 12) For media inside the container that are extremely or highly toxic, overall reinforcement (i.e., increasing the shell thickness) or reinforcement using local overall reinforcing elements shall be employed – according to HG/T20583-2011, clause 9.2.2. 13) For containers holding highly or extremely toxic substances, glass tube level gauges and glass float level gauges are not permitted. ——HG/T20583-2011, Clause 10.1.3 P447. Level gauges used on pressure vessels containing media with an extremely high or high degree of toxicity are equipped with protection devices to prevent leaks. ——Fixed volume gauge, P98, clause 9.2.2.1(5). 14) For containers with a medium toxicity level that constitutes extreme or high hazard, a leakage test shall be conducted after the pressure resistance test is passed—GB150.1-2011, Clause 4.7.2. After passing the pressure test, pressure vessels containing media with an extremely high or high degree of toxicity shall undergo a leakage test. -----Paragraph 3.1.18, P19 of the Fixed Volume Gauge.