Design specifications for Class III pressure vessels and high-hazard medium applications

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Design specifications for Class III pressure vessels TSG21-2016 1. Forge products of Grade IV used for Class III pressure vessels shall be retested. P6 2. The general design drawings of Class III pressure vessels, the risk assessment report, the strength calculation sheet, or the stress analysis report must be approved by the person in charge of pressure vessel design technology or their authorized representative. P15 3. For Class III pressure vessels, a risk assessment report shall be prepared during design, including information on the main failure modes (hazard identification) and risk control measures. P16 4. The weld joints between the nozzles (flanges) of Class III pressure vessels and their shells, as well as the weld joints of jacketed pressure vessels, shall adopt a fully penetrated weld structure. P21 5. For Class III pressure vessels with a design pressure of ≥1.6 MPa, 100% non-destructive testing shall be carried out on their Class A and Class B weld joints. P23 6. For Class III pressure vessels with a design pressure of ≥10 MPa, when carbon steel and low-alloy steel plates with a thickness of ≥12 mm (excluding the plates of multi-layer pressure vessels) are used to manufacture the main pressure-bearing components of such vessels, ultrasonic testing shall be carried out on each plate individually. In accordance with NB/T 47013.3-2015, the testing technique level shall be Grade B, and the acceptance level shall be no lower than Grade II. P8 2 I: Design specifications for high-hazard medium service conditions TSG21-2016 1. When carbon steel and low-alloy steel plates with a thickness of ≥12 mm (excluding the plates of multi-layer pressure vessels) are used to manufacture the main pressure-bearing components of pressure vessels, and the toxicity level of the medium contained is extremely or highly hazardous, ultrasonic testing shall be carried out on each plate. In accordance with NB/T47013.3-2015, the testing technique grade shall be Grade B, and the acceptance grade shall be no lower than Grade II. P8 2. After passing the pressure test, leakage tests shall be conducted on pressure vessels whose medium is extremely or highly toxic, or for which minor leaks are not permitted due to design requirements. P19 3. For pressure vessels whose medium is explosive or whose toxicity poses an extreme or high level of hazard, the joint design between the nozzle (flange) and the vessel shell, as well as the joint design for jacketed pressure vessels, shall adopt a fully penetrated structure. P21 4. For pressure vessels containing extremely or highly hazardous toxic media, it is necessary to prepare product welding specimens. P22 5. For pressure vessels used to hold liquefied petroleum gas, as well as media with an extremely high or high level of toxicity, or medium-hazardous media with strong permeability, their pipe flanges shall, in accordance with the provisions of the HG/T 20592 series of standards, use at least high-neck butt weld flanges, metal wound gaskets equipped with reinforcing rings, and specialized high-strength bolts. Where such pipe flange sealing combinations cannot be used, the designer shall determine the flange connection structure based on the properties of the medium, pressure, and temperature. P22 6. Welded joints of pressure vessels containing media with an extremely high or high toxicity level require magnetic particle or penetrant testing on their surfaces. P24 GB/T 150.1~150.4-2011: 1. For containers whose medium is extremely toxic, highly hazardous, or for which even trace leaks are not permitted, a leakage test shall be conducted after the pressure resistance test is passed. P15 2. The blast fragment safety device cannot be used alone in situations where the toxicity of the medium is extremely high, highly hazardous, or where explosive substances and liquefied petroleum gas are involved; in such cases it can be used in combination with a safety valve. P19 3. The method for determining the design pressure of containers specified in Appendix C of GB/T150.1-2011, namely through verification blasting tests, shall not be used for the design of containers intended to hold extremely hazardous or highly hazardous substances. P27 4. Steels 10, 20, and Q345D specified in GB/T8163 shall not be used for media with an extremely high or high degree of toxicity. P53 5. Q235B and Q235C steel plates shall not be used for media with an extremely high or high level of toxicity. P87 6. Carbon steel and low-alloy steel containers used to hold media with extremely or highly hazardous toxicity shall undergo post-weld heat treatment. P332 7. For containers holding extremely or highly hazardous toxic substances, and those with Class A longitudinal weld joints, weld test pieces shall be prepared for each individual product. P333 8. Containers holding extremely or highly hazardous toxic materials require that all Class A and Class B weld joints be subjected to radiographic or ultrasonic testing in accordance with the methods specified in the design documents. P335 HG/T 20580~20585-2020 1. For forgings used in media with extremely high or high toxicity, they shall meet the requirements of Grade III or Grade IV. P84 2. For containers holding explosive media and moderately hazardous media, the PN of the container flange should not be lower than 0.6 MPa ； For containers whose filling medium is an extremely or highly hazardous medium, as well as a highly permeable medium, the PN of the container flange should not be lower than 1.0 MPa. P472 3. For containers holding explosive hazardous materials and moderately toxic hazardous materials, the nominal pressure class of the container’s nozzle flange should be no less than 1.6 MPa ； For containers holding extremely toxic and highly hazardous media, as well as highly permeable media, the nominal pressure class of the container’s connection flanges should be at least 2 MPa. P473 4. For containers holding extremely toxic and highly hazardous media, highly permeable media, or moderately toxic media, the flanges on their connections should be socket weld flanges with a neck. P473 5. For containers holding extremely hazardous or highly dangerous media with a wall thickness of 12 mm or more, reinforcement using integral reinforcement or local integral reinforcement elements shall be employed. P480 6. Glass tube level gauges and glass float level gauges should not be used when the container holds explosive substances or substances with moderate, high, or extremely high toxicity. P484 7. When the container holds explosive materials, or materials that are extremely toxic, highly hazardous, or moderately hazardous due to their strong permeability, fully penetrative welds should be used. P533