Design approval defense: Storage tank

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Case 1: I. Drawing design parameters: Medium: liquid chlorine, highly hazardous. Design temperature: -40°C; design pressure: 2.5 MPa. Specifications: DN2600×20 mm. Material: 16MnDR. II. Issues with the drawings: 1) The supply condition of the 16MnDR material was not specified； 2) The impact work indicator is incorrect ； 3) Classes A, B, C, D, E: No surface inspection required ； 4) The sheet metal was not subjected to ultrasonic testing ； 5) No safety relief device is installed ； 6) The manhole is reinforced with a reinforcing ring; it is recommended to use overall reinforcement instead. III. Teacher’s questions regarding the drawings: 1) What are the main differences between the new capacity regulations and the old ones? 2) What are the requirements for the S and P contents of materials under the new regulatory standards? 3) How to eliminate welding residual stress? 4) How are thick-walled containers distinguished from thin-walled containers? State of stress? 5) How is the heat treatment temperature determined? And how to control the temperature? 6) What are the reinforcement methods in GB150.3? What is the scope of application of the equal area method and the analytical method? Why does the equal area method have limitations? What is the purpose of opening reinforcement? 7) What are the two types of hook-and-loop floating head flanges? What is the difference, and what are the application scenarios? 8) How are allowable stresses considered for high-temperature and low-temperature applications? Strain strengthening? 9) In equipment flanges, what should be done when the taper size of the long-neck flange differs from that of the butted cylinder due to uneven thickness? And when to use surfacing, and when to use a 3:1 beveling? 10) Problems with stainless steel heat treatment? Solution treatment? 11) What aspects are mainly considered for heat treatment in liquid chlorine storage tanks? 12) Stress model of ear-type support, stress analysis of skirt base transition section. Case 2
I. Design parameters of the drawings
Design pressure: 1.77 MPa; Design temperature: 50°C. Medium: Liquefied petroleum gas. Equipment diameter: 3200 mm; Wall thickness: 26 mm. Setting pressure of the safety valve: 1.75 MPa.

II. Issues with the drawings
1. Heat treatment is not specified in the drawings.
2. The mounting method for the saddle is reversed; the positioning does not follow the dimensions recommended for horizontal containers.
3. Type D welds require full penetration.
4. There is no need for an internal extension at the drain outlet; moreover, an anti-vortex device is required.
5. The gasket and studs for the manhole are inappropriate (specified as XB350, 8.8 in the drawings).
6. The flange type should be changed from SO to WN.
7. The setting pressure of the safety valve is 1.75 MPa; if this value is increased according to the upper tolerance limit, it will exceed the design pressure.

III. Questions from the instructor regarding the drawings
1. For equipment with linings, hydraulic testing is not possible, nor is pneumatic testing allowed. What issues need to be considered (from the aspects of design, manufacturing, operation, maintenance, and inspection)?
2. What are the stress conditions for socket weld connections, plug weld connections, and butt weld connections (Type A saddle welds)? Precautions for fixed-type connections 3. What considerations should be taken in the manufacturing of Cr-Mo steel equipment? 4. For equipment used in heat treatment, how can one determine whether the heat treatment has been successful? 5. The purpose of pressure testing 6. The scope of application for reinforcement rings 7. Are there any requirements regarding the number of manholes in horizontal containers? 8. Issues related to the installation of manholes or openings at the top of horizontal containers supported by double saddle supports 9. Why is stainless steel commonly used for grounding plates? 10. The application of conical skirts and the range of control for the semi-cone angle