2006 Pressure Vessel Design Reviewer Assessment Paper

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Closed-book Examination Questions for the Assessment of Pressure Vessel Design Reviewers, Issue 4, 2006 I. Fill-in-the-blank questions (20 points) 1. For pressure-bearing components whose structural dimensions cannot be determined using GB150, GB150 permits the use of stress analysis methods, including the finite element method, for design purposes. 2. GB150 stipulates that when determining the allowable stress of steel materials, consideration must be given to the material’s tensile strength, as well as its creep limit. 3. When conducting hydraulic testing on pressure vessels made of austenitic stainless steel using water, the chloride ion content in the water must be strictly controlled to not exceed 25 mg/L. Once the test is passed, the water stains should be removed immediately. 4. The maximum allowable operating pressure is determined based on the calculations of the vessel shell, taking into account the values for each stressed component. 5. In heat exchanger design, the strength expansion grooves are provided to increase the contact between the tube sheet and the heat exchange tubes, while the requirement regarding the roughness of the tube holes is aimed at . 6. The transition layer in the cladding of stainless steel surfacing tube sheets shall be surfaced using stainless steel electrodes or welding strips. 7. In horizontal shell-and-tube heat exchangers, where there is a gas-liquid mixture in the shell side or solid particles are present in the liquid phase, baffle notches should be installed. 8. The spherical tank can be regarded as a _ system, for which the basic natural vibration period is calculated. 9. For the welds of the sphere shell and those that are directly welded to it, flux-coated electrodes should be used, and re-inspection should be carried out by batch. 10. In accordance with GB150, overpressure relief devices are not suitable for pressure vessels where a sudden increase in pressure may occur during operation, resulting in a reaction speed high enough to lead to detonation. 11. The maximum design pressure of the aluminum container is MPa ； The maximum design pressure of the titanium container is MPa. 12. GB150 is not applicable to vessels with a design pressure below 0.1 MPa and a vacuum level below 0.02 MPa. 13. Stainless steel with a carbon content of not less than is called low-carbon stainless steel ； Stainless steel with a carbon content of not less than a certain value is referred to as ultra-low carbon stainless steel. 14. According to the direction of the applied force and the deformation characteristics during instability, external pressure cylinders exhibit two types of instability. 15. For containers in which inspection holes cannot be provided due to special circumstances, this shall be indicated on the design drawings, and details shall be provided. 16. The phosphorus content in steel plates specifically designed for pressure vessels should not exceed , and the sulfur content should not exceed . 17. When austenitic stainless steel is used at temperatures above 525°C, the carbon content in the steel must be at least . 18. When designing storage tanks for liquefied petroleum, for the first flange sealing surface connected by flanges, a combination of flanges, gaskets (with), and bolts should be used. 19. Titanium materials used for manufacturing pressure vessel shells should be used in their proper state. 20. Calculated pressure refers to the pressure used to determine it at the corresponding temperature. 21. The supports for horizontal containers mainly include saddle-type and ring-type ones. 22. The arrangement patterns of heat exchange tubes are mainly regular triangles, angled regular triangles, squares, and angled squares. The center-to-center distance between heat exchange tubes is generally not less than 1.25 times the outer diameter of the tubes. 23. The design burst pressure of a rupture disc refers to the burst pressure of that disc at a specified temperature. 24. Ultrasonic testing shall be conducted within the perimeter area of the shell plate. 25. The shaft sealing types for mixing vessels include three types: , and . 26. For containers holding liquids, full-opening or slightly-opening safety valves should be used. 27. Although the calculation methods for externally pressurized cylinders vary, they are generally derived based on formulas. 28. The nozzle flange of the spherical tank shall use a flange. 29. The calculated pressure refers to the pressure used to determine the thickness of a component at the corresponding design temperature. 30. When selecting steel for pressure vessels, the operating conditions of the vessel must be taken into account, such as design pressure, design temperature, properties of the medium, and operational characteristics. Weldability of the material, manufacturing process of the container, and economic viability. 31. When the nominal diameter of the flange bolts is >M48, fine-thread threads should be used. 32. Edge stress has two basic characteristics: locality and self-limitation. 33. For low-temperature vessels and vessels subject to stress corrosion, and are effective measures to reduce local high stresses. 34. The compressive force per unit effective sealing area of the gasket under pre-tension is called the sealing specific pressure, denoted by Y. 35. Welding stress arises from uneven deformation caused by welding, and its main hazards include , , etc. 36. When considering vertical seismic forces in both the upward and downward directions for tower-type containers, their design intensity is designated for zones 8 and 9. II. Multiple-choice Questions (20 points) 1. A pressure vessel under external pressure has a diameter of φ1200 mm, a cylinder shell length of 2000 mm, and hemispherical end caps; its calculated length for external pressure is 2400. a. 2000 mm b. 2400 mm c. 2600 mm 2. The stress caused by an axial temperature gradient in a cylinder shell belongs to b. secondary stress a. primary bending stress b. secondary stress c. peak stress 3. GB150 does not apply to the following vessels a. Vessels with an operating pressure of 0.05 MPa and a design pressure of 0.1 MPa ； d. Flame-heated disinfection pot b. LPG cylinder ； c. Vertical containers ； d. Flame-heated disinfection pot. 4. The return period of the basic wind pressure is 20 years ； b 30 years ； c 40 years ； d 50 years 5. A pressure vessel is composed of four pressure-bearing elements. After calculation, the maximum allowable operating pressures for the four components are respectively Pw1=2.14 MPa, Pw2=2.41 MPa, Pw3=2.25 MPa, and Pw4=2.15 MPa. Please determine the maximum allowable operating pressure for this container: Pw = 2.41 MPa. a. Pw=2.14 MPa, b. Pw=2.15 MPa, c. Pw=2.25 MPa, d. Pw=2.41 MPa. 6. Which of the following shell structures are not suitable for heat-wall hydrogenation reactors? a. Single-layer rolled weld ； b. Heat sleeve ； c. Forge welding d. Multi-layer wrapping ； 7. JB 4708 specifies that when conducting impact toughness tests on welded joints, impact specimens shall be prepared from ______ a. weld zone, fusion zone, heat-affected zone ； b. Weld zone, heat-affected zone, base metal ； c. Weld zone, heat-affected zone ； d. Weld zone, coarse-grain zone, heat-affected zone ； 8. In the strength calculation of horizontal vessels, when the combination of seismic forces and other loads is taken into account, the allowable stress in the shell wall shall not exceed times the allowable stress. a1.0 b1.1 c1.2 d1.5 9. In which of the following situations is it necessary to use a burst disc device as a pressure relief mechanism for pressure vessels? a a. The medium inside the container is an extremely or highly hazardous medium ； b. The pressure inside the container increases rapidly ； c. The container has high requirements for sealing ； d. Pressure vessels with a design pressure higher than 10 MPa. 10. The main bolt a of pressure vessel equipment is the primary compressive member. a. M≥36 b. M>36 11. Medium-pressure reaction vessels containing media that are flammable or moderately toxic, with a PV product of 0.5 MPa·m3 or greater, should be classified as category III pressure vessels. A) 0.1 B) 0.05 C) 0.5 D) 0.45 12. For the third category of medium-pressure reaction vessels and storage vessels, high-pressure vessels, and mobile pressure vessels, the person who signs on the design layout diagram must be . A) Design, proofreading, review B) Design, verification, review (finalization) C) Design, proofreading, review (finalization), person in charge of pressure vessel design technology. 13. When designing storage vessels, if the metal temperature of the shell is affected by the ambient air temperature, the minimum design temperature shall be taken as the lowest value among the average annual minimum temperatures over the years. A) Month B) Year C) Day D) 100 days 14. For which of the following equipment connections is it not necessary to perform radiographic or ultrasonic testing on all of them?: A) Class III pressure vessels B) Pressure vessels with a design pressure greater than 5.0 MPa C) Those that are tested using pneumatic testing D) Shell-and-tube waste heat boilers with a design pressure less than 0.6 MPa. 15. Among the following thicknesses, the minimum thickness that meets the requirements for strength and service life is . C) Design thickness A) Nominal thickness B) Calculated thickness C) Design thickness. 16. Steel plates of 20R and 16MnR that are used for pressure-bearing components such as flanged tube sheets and flat covers, and whose thickness is greater than a certain value, should be used in the normalized state. A) 30mm B) 40mm C) 50mm 17. The main bolts of the equipment are made of 35CrMoA material; in what heat treatment condition should they be used? B) Quenching and tempering. A) Normalizing B) Quenching and tempering C) Stabilization treatment 18. According to the standard \"Steel Pressure Vessels\" GB150-1998, when the inner diameter Di of the cylinder is greater than 1500 mm, the maximum diameter d of the opening must be less than or equal to 1/3Di, and also less than or equal to 1000 mm. A) 1/2 B) 1/3 C) 500 D) 1000 E) 520 19. When the design temperature of the heat exchanger is ≥300℃, the pipe flanges should be of . A) Butt weld flange B) Welded flange with neck C) Plate welded flange 20. When joining heat exchange tubes, each tube after butting should be subjected to a hydraulic test, with the test pressure being of the design pressure. A) 1.25 times B) 1.5 times C) 2 times 21. Which of the following statements is correct? A) The thickness of the partition plate in a heat exchanger can be selected according to the table; there is no need to perform strength checks ； B) The thickness of the partition plates in the heat exchanger must be checked for strength ； C) The thickness of the partition plates in the heat exchanger shall be checked for strength as necessary ； D) When corrosion is severe, the split diaphragm of the heat exchanger should take into account double-sided corrosion. 22. When the negative deviation of the steel thickness is not greater than 0.25 mm and does not exceed a certain percentage of the nominal thickness, it can be ignored. A) 3 B) 6 C) 10 23. The butt weld joints of titanium pressure vessels must be inspected by radiography or ultrasonic testing. A) >20% B) 100% 24. The liquid temperature during the hydraulic test of low-temperature heat exchangers should be no lower than the temperature used in the impact test plus ℃. A) 15 B) 20 C) 25 25. The design thickness for a steel plate with a thickness of 12.75 mm, a corrosion margin of 2 mm, and a negative deviation in thickness of 0.25 mm is . A) 14.5mm B) 14.75mm D) 15mm 26. The inner wall temperature of the container is 150°C, and the outer wall temperature is 142°C; the design temperature should be taken as °C. A) 142 B) 146 C) 150 27. The nozzles and pipe flanges of pressure vessels, when considered in terms of their nominal diameter, are the main pressure-bearing elements. A) ≥250mm B)