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Question bank for theoretical assessments of pressure vessel operators: I. True or False questions: 1. The Constitution of the People’s Republic of China stipulates that all power in the People’s Republic of China belongs to the people. In accordance with the law, the people manage **affairs, economic and cultural activities, as well as social affairs, through various forms and channels. ( ) 2. The Labor Law of the People’s Republic of China stipulates that workers engaged in special types of work must receive specialized training and obtain the necessary qualifications for such work. ( ) 3. The Labor Law of the People’s Republic of China stipulates that workers must strictly abide by safety operating procedures during work; workers have the right to refuse to carry out orders that come from management personnel who give illegal instructions or force them to work in hazardous conditions ； One has the right to criticize, report, and file complaints against actions that endanger life safety and physical health. ( ) 4. The Labor Law of the People’s Republic of China stipulates that employers shall establish and improve rules and regulations in accordance with the law, so as to ensure that workers can enjoy their labor rights and fulfill their labor obligations. ( ) 5. The Work Safety Law of the People’s Republic of China stipulates that production and business operation entities must abide by this law as well as other laws and regulations related to work safety, strengthen work safety management, establish and improve work safety responsibility systems, and enhance work safety conditions to ensure safe production. ( ) 6. The Work Safety Law of the People’s Republic of China stipulates that employees of production and business entities have the right to receive safety protections in accordance with the law, and they shall also fulfill their obligations regarding work safety as required by law. ( ) 7. The Work Safety Law of the People’s Republic of China stipulates that production and business operation entities shall educate and urge their employees to strictly comply with the entity’s work safety rules and regulations as well as safety operating procedures ； It is also necessary to inform the workers truthfully about the hazardous factors present in the workplace and at their posts, as well as the preventive measures and emergency response procedures in case of accidents. ( ) 8. The Work Safety Law of the People’s Republic of China stipulates that the person in charge of a production or business operation entity is fully responsible for the work safety within that entity. ( ) 9. The Work Safety Law of the People’s Republic of China stipulates that people’s governments at all levels and their relevant departments shall adopt various measures to strengthen the promotion of laws, regulations, and knowledge related to work safety, thereby raising workers’ awareness of work safety. ( ) 10. The Work Safety Law of the People’s Republic of China stipulates that: **a system for holding persons responsible for work safety accidents shall be implemented, and in accordance with the provisions of this law as well as relevant laws and regulations, legal liability shall be imposed on those responsible for such accidents. ( ) 11. The Work Safety Law of the People’s Republic of China stipulates that when employees discover an emergency situation that poses an immediate threat to their physical safety, they have the right to stop working or leave the workplace after taking any possible emergency measures. ( ) 12. The \"Regulations on the Safety Supervision of Special Equipment\" are administrative regulations that were approved at the 68th executive meeting of the State Council on February 19, 2003; they were promulgated by Decree No. 73 of the State Council on March 11 of the same year, and came into effect on June 1 of that year. ( ) 13. The purpose of formulating the Regulations on Safety Supervision of Special Equipment is to strengthen the safety supervision of such equipment, prevent and reduce accidents, safeguard the lives and property of the public, and promote economic development. ( ) 14. The Regulations on the Safety Supervision of Special Equipment stipulate that if special equipment operators fail to follow the operating procedures for such equipment as well as relevant safety rules and regulations, or if they discover potential accident hazards or other unsafe factors during operation but fail to report them immediately to the on-site safety managers and relevant responsible persons of the unit, the special equipment user shall give them criticism and disciplinary action ； Those who violate criminal law shall be held criminally liable in accordance with the provisions of the Criminal Law regarding the crime of major liability accidents or other crimes. ( ) 15. The Regulations on the Safety Supervision of Special Equipment stipulate that special equipment includes its attached safety accessories and safety protection devices. ( ) 16. The \"Regulations on Safety Inspection of Pressure Vessels\" stipulate that the entities using pressure vessels shall clearly specify the safety operation requirements for such vessels in their process operation procedures and job-specific operation procedures. These requirements should include at least the following: (1) The operational parameters of the pressure vessel (including the maximum operating pressure, as well as the maximum or minimum operating temperature). (2) Operating procedures for pressure vessels (including start-up and shutdown procedures and precautions). (3) Key items and areas to be inspected during the operation of pressure vessels, possible abnormal phenomena that may occur during operation, and preventive measures. ( ) 17. The Regulations on the Safety Supervision of Special Equipment stipulate that entities that use special equipment shall provide safety education and training for the personnel who operate such equipment, to ensure that they possess the necessary knowledge regarding safety in handling special equipment. Special equipment operators must strictly follow the operating procedures for such equipment as well as relevant safety regulations during their work. ( ) 18. The Regulations on the Safety Supervision of Special Equipment stipulate that operators of boilers, pressure vessels, elevators, lifting machinery, passenger cableways, and large-scale amusement facilities, as well as their relevant management personnel (hereinafter collectively referred to as special equipment operators), must pass assessments conducted by the authorities responsible for the safety supervision of special equipment in accordance with **relevant regulations**, and obtain certificates for special operation personnel in a unified format, before they can engage in the corresponding operations or management tasks. ( ) 19. The Regulations on the Safety Supervision of Special Equipment stipulate that special equipment operators, upon discovering potential accident hazards or other unsafe factors during operation, shall immediately report them to the on-site safety managers and the person in charge of the unit. ( ) 20. The \"Regulations on Safety Inspection of Pressure Vessels\" stipulate that the regular inspection of pressure vessels includes external inspections as well as internal and external inspections. ( ) 21. The \"Regulations on the Safety Supervision of Gas Cylinders\" stipulate the basic requirements for the safety of gas cylinders. The design, manufacturing, filling, transportation, storage, distribution, use, and inspection of gas cylinders shall all comply with the provisions of these regulations. ( ) 22. The Regulations on Safety Supervision of Gas Cylinders stipulate that gas cylinders must be used for specific purposes only. Only media that match the stamp marking are allowed to be filled; it can be modified for use. ( ) 23. The Regulations on Safety Supervision of Gas Cylinders stipulate that filling units must provide training for filling personnel and those responsible for pre-filling inspections on topics such as the properties of gases, basic knowledge of gas cylinders, potential hazards, and emergency response measures. ( ) 24. The Regulations on Safety Supervision of Gas Cylinders stipulate that the steel stamp markings on gas cylinders serve as the basis for identifying them. The stamp mark must be accurate, clear, and complete, printed in the form of a permanent mark on the bottle shoulder or an unremovable attachment. （ ） 25. The Regulations on Safety Supervision of Gas Cylinders stipulate that filling units must meet the requirements of the relevant safety and technical standards for filling stations, strictly adhere to the regulations regarding gas cylinder filling, and ensure that no incorrect filling, overfilling, or mixing of gases occurs, as well as enable traceable inspection of the quality of the filling. ( ) 26. \"Safety Supervision Regulations for Dissolved Acetylene Cylinders\" – The provisions of these regulations represent the basic requirements for the safety of acetylene cylinders. The design, manufacturing, filling, inspection, transportation, storage, and use of acetylene cylinders must comply with the requirements set out in these regulations. ( ) 27. The Safety Inspection Regulations for Dissolved Acetylene Cylinders stipulate that cylinder caps must meet the following requirements: they should be fixed, meaning that it is possible to easily fill the acetylene cylinder with solvent, use the acetylene, and perform other operations without having to remove the cylinder cap ； It has good impact resistance, can effectively protect the bottle valve, does not allow gas or liquid to accumulate, and is easy to clean of dirt ； Gray cast iron shall not be used for manufacturing ； Indicate the weight value in a prominent place. For bottle caps of the same specification manufactured by the same manufacturer, the weight tolerance shall not exceed 5%. ( ) 28. The Safety Supervision Regulations for Dissolved Acetylene Cylinders stipulate a system of designated filling units for acetylene cylinders. If the cylinder is not from this filling facility, it can be retrieved and refilled upon agreement. （ ） 29. The Safety Supervision Regulations for Dissolved Acetylene Cylinders stipulate that acetylene cylinders must not be filled again until they have been properly purged after being filled for the first time or after having had their cylinder valves or fusible alloy plugs replaced. ( ) 30. The Safety Supervision Regulations for Dissolved Acetylene Cylinders stipulate that acetylene cylinder filling units must fill out filling records carefully for each cylinder, and such records must be retained for at least 12 months. ( ) 31. A pressure vessel refers to a sealed device that contains gases or liquids and is subject to certain pressures. ( ) 32. Due to the specific conditions of pressure and the medium involved, pressure vessels are at risk of failure and explosion. An explosion in a pressure vessel not only damages the vessel itself but also endangers the safety of the entire installation and the surrounding area, resulting in **property damage and casualties. ( ) 33. The strength of a pressure vessel refers to its ability to resist rupture under a certain pressure or other external loads. ( ) 34. The service life of pressure vessels depends on factors such as their fatigue life and corrosion rate. （ ） 35. The sealing performance of pressure vessels refers to the sealing at the detachable connections. （ ） 36. The design pressure indicated on the pressure vessel’s nameplate can be less than the maximum operating pressure. ( ) 37. The design temperature indicated on the pressure vessel nameplate refers to the design temperature of the vessel’s shell. ( ) 38. For the toxic substances and flammable or explosive substances contained in pressure vessels, which pose a serious threat to operators, strict monitoring and preventive measures must be implemented to ensure the safe operation of these pressure vessels. ( ) 39. Pressure vessels are classified according to their functional principles in the production process as: reaction pressure vessels (code R), heat exchange pressure vessels (code E), separation pressure vessels (code S), and storage pressure vessels (code C; spherical tanks are coded as B). ( ) 40. The \"Regulations on Safety Inspection of Pressure Vessels\" takes into full account factors such as the operating pressure of the vessel, the degree of hazard posed by the medium, the functions of the vessel, its structural characteristics, and the overall impact on its safety performance. Based on these factors, pressure vessels are classified into three categories: Class I, Class II, and Class III, to facilitate safe technical supervision and management. ( ) 41. Spherical pressure vessels are mostly constructed on-site by welding together numerous spherical segments that have been pre-formed to specific dimensions; they consist of polar zones and equatorial zones. ( ) 42. The cylindrical pressure vessel body is composed of main components such as the cylinder shell, end caps, flanges, nozzles, and supports, which are welded together. ( ) 43. The \"Regulations on Safety Inspection of Pressure Vessels\" stipulate that radiographic testing must be carried out on the welds used to join the head sections after they are formed. This is because the arc-shaped transition areas of the head sections experience significant deformation and considerable thinning, so it is necessary to ensure that the strength requirements are met. ( ) 44. The reinforcement using a reinforcing ring is designed based on the principle of equal-area reinforcement; that is, the additional cross-sectional area needed is merely greater than or equal to the area lost due to the opening, in order to meet the reinforcement requirements. ( ) 45. Sealing leaks in the flanges of pressure vessel equipment and the flanges of connections occur due to excessive elastic deformation, which is caused by insufficient strength leading to the failure of the sealing structure. （ ） 46. The sealing of pressure vessels refers to the sealing at detachable connections. ( ) 47. The sealing elements of pressure vessels refer to the components that provide sealing at the detachable connections. It is placed between the contact surfaces of two flanges or end caps and the cylinder end, and provides sealing through the compressive force exerted by fasteners such as bolts. ( ) 48. The maximum operating pressure of a pressure vessel refers to the highest pressure that may occur at the top of the vessel under normal operating conditions. ( ) 49. The design pressure of a pressure vessel indicated on its nameplate can be less than the maximum operating pressure. ( ) 50. The pressure in a tank used for storing liquefied gas depends on the saturated vapor pressure of the liquefied gas at the storage temperature. ( ) 51. The design temperature indicated on the nameplate of a pressure vessel refers to the design temperature of the vessel’s shell. ( ) 52. When pressure vessels contain toxic substances, the maximum allowable concentration of such substances in the operating environment refers to the limit value that harmful substances in the air at the operator’s workplace must not exceed. The workplace refers to the place where workers stay regularly or periodically in order to observe and manage the production process. ( ) 53. The lower explosion limit refers to the lowest volume percentage of flammable gas or vapor in air at which it is just sufficient to enable the flame to propagate ； The upper explosion limit refers to the volume percentage of flammable gas or vapor in air at which it reaches the highest concentration sufficient for the flame to propagate. ( ) 54. Flammable media refer to gases whose lower explosive limit when mixed with air is 20%. ( ) 55. The main sources of fire that need to be controlled in order to prevent the combustion and explosion of flammable materials include: furnace flames, heat generated by reactions, electric sparks, fire used for maintenance, mechanical friction, spark from impacts, sparks from control electrical equipment, and smoking. ( ) 56 When selecting steel for pressure vessels, it is necessary to take into account factors such as the design temperature, design pressure, and operating conditions of the vessel, as well as the weldability of the material, the manufacturing process for the vessel, and economic viability. ( ) 57. The plasticity of steel materials used for pressure vessels is indicated by the elongation rate (δ) and the reduction of area (Ψ). It indicates the ability of a metal material to undergo plastic deformation under stress. Its value represents the plastic deformation capacity of the specimen under tensile stress. ( ) 58. Hardness refers to a material’s ability to resist local plastic deformation, that is, its ability to resist being pressed by hard objects. Commonly used hardnesses include Brinell hardness (HB) ； Rockwell hardness (HR) ； Vickers hardness (HV). ( ) 59. Impact toughness refers to the work absorbed by a material when it breaks under the action of an impact load. The impact toughness value αkv refers to the work absorbed by a material specimen of certain shape and size when it breaks under the action of an impact load. ( ) 60. Common steel grades used for pressure vessels include carbon steel, low-alloy steel, pearlitic heat-resistant steel, low-temperature steel, stainless steel, and others. （ ） 61. When repairing or replacing the pressure-bearing components of a pressure vessel, the quality of the materials used should be higher than that of the materials specified in the original design. ( ) 62. Stress is the internal force per unit area within a component, resulting from external forces acting on that component; pressure is a force that acts perpendicularly on the surface area of an object, and it constitutes an external force for structural elements. ( ) 63. Film stress, thermal stress, and local stress have different effects and consequences on pressure vessels, but ultimately they can all lead to the failure of such vessels. （ ） 64. Chemical corrosion of metals is the corrosion that occurs as a result of chemical reactions between the metal and its surrounding environment. This type of corrosion mainly includes the corrosion of metals in dry or high-temperature gases, as well as the corrosion of metals in electrolyte solutions. High-temperature corrosion, high-temperature oxidation, carburization and decarburization of steel, hydrogen corrosion, etc., are typical forms of chemical corrosion. （ ） 65. In an electrolyte solution, since the potential of iron in the metal is low while that of impurities is high, these impurities lose electrons and turn into iron ions within the corrosion current circuit, thereby accelerating corrosion. （ ） 66. The carburization products of steel are fibrous flakes or powdery oxides, carbides, graphite, and other high-strength brittle substances. Decarburization of steel reduces the amount of cementite in its surface layer, thereby increasing the surface hardness and fatigue strength of the steel. （ ） 67. The discharge capacity of the safety valve must be greater than or equal to the safe release capacity of the pressure vessel; the opening pressure of the safety valve shall not be lower than the design pressure of the pressure vessel. If the highest operating pressure in the system is used as the opening pressure of the safety valve, then the operating pressure of each pressure vessel in the system should correspond to this value. （ ） 68. The lead seal on the safety valve must not be removed without permission, and its nameplate and other markings must not be taken off or replaced without authorization. ( ) 69. Safety valves should generally be inspected at least once a year, and the inspection tasks include cleaning, grinding, part replacement, pressure testing, and airtightness testing. The set pressure value of the safety valve must not be changed arbitrarily, and it shall not exceed the design pressure of the container. ( ) 70. Safety valves should be kept clean at all times to prevent them from becoming clogged with oil residues or dirt, or from rusting. It is necessary to check regularly whether the seals are intact, whether freezing is possible at low temperatures, and whether there is any leakage from the safety valves. ( ) 71. When a safety valve and a burst disc device are used in parallel, the set pressure of the burst disc shall not exceed the design pressure of the container. The opening pressure of the safety valve should not exceed the set pressure of the burst disc. ( ) 72. When a burst disc device is used in series with a safety valve, and the burst disc device is located on the outlet side of the safety valve, it is necessary to check the pressure gauge and shut-off valve between the burst disc device and the safety valve; any pressure that builds up between them should be able to be drained or vented ； When the rupture disc device is located on the inlet side of the safety valve, it is necessary to check whether there is pressure indication on the pressure gauge between the rupture disc device and the safety valve, and whether gas leaks out after the stop valve is opened, in order to determine the condition of the rupture disc. ( ) 73. According to the Regulations on Safety Inspection of Pressure Vessels, the accuracy of pressure gauges used in low-pressure vessels must be at least 2.5 grade ； The accuracy of pressure gauges used in medium-pressure or high-pressure vessels shall be no less than grade 1.5 ； The pressure gauges used for verifying the set pressure of safety valves and the burst pressure of rupture disks must have an accuracy of not less than grade 1. （ ） 74. When using a pressure gauge for oxygen, care should be taken to avoid using it under conditions of oil-based calibration or exposure to high temperatures. ( ) 75. The maximum range of the pressure gauge used in pressure vessels should be appropriate to the operating pressure of the vessel. According to the \"Regulations on Safety Inspection of Pressure Vessels\", the maximum range of the pressure gauge should be 1.5 to 3.0 times the highest operating pressure; it is advisable to choose a range that is 2 times that value. ( ) 76. The flat head is the most commonly used type of head in the manufacture of pressure vessels. ( ) 77. Cylindrical pressure vessels have a wider range of applications than spherical pressure vessels; spherical pressure vessels are generally used only as storage vessels for liquids or liquefied gases. （ ） 78. The main advantages of cylindrical pressure vessels are their ease of manufacture and the convenience they offer for installing internal process components; as a result, their production and usage volumes are higher than those of spherical and cubic vessels. ( ) 79. The main advantages of spherical pressure vessels are low stress and uniform stress distribution; they require less surface area for the same volume, thus saving materials and investment. ( ) 80. The most commonly used type of convex head in pressure vessels is the elliptical head. （ ） 81. Within the same volume, the explosive energy of a system in which the working medium is gas is hundreds to tens of thousands of times greater than that of a system where the working medium is a liquid (non-liquefied gas). （ ） 82. Within the same volume and under the same pressure conditions, the explosive energy when there is a high-temperature saturated liquid present is much greater than that when there is saturated steam present. （ ） 83. Full-opening safety valves open quickly, while their closing action is relatively smooth. ( ) 84. The discharge capacity of a fully open safety valve is related to the cross-sectional area of its seat throat, as well as to its lift height. ( ) 85. The discharge capacity of a slightly opening safety valve is related to the cross-sectional area of its seat throat, as well as to its lift height. ( ) 86. For safety valves with the same seat throat diameter, their discharge capacity in the fully open position is the same as that in the slightly open position. ( ) 87. The load applied to the weight of the lever-type safety valve increases as the valve disc rises. ( ) 88. The nominal diameter of a safety valve refers to the throat diameter of the valve seat. ( ) 89. The bursting pressure of the rupture disc shall not be greater than the design pressure of the pressure vessel. The lower its value, the higher the requirements for manufacturing the burst disc. ( ) 90. A fuse plug is a temperature-based safety relief device; it requires that the increase in pressure occur simultaneously with the increase in temperature, at the same rate, so as to effectively prevent pressure vessels from experiencing overpressure due to rising temperatures. ( ) 91. The over-flow control valve installed on the emergency shut-off valve device is intended to maintain the rated flow rate. ( ) 92. The emergency shut-off valves used in tanks and tank trucks should be in a closed state while the vehicle is in motion, and they must not be used as stop valves as well. （ ） 93. If the maximum scale value of a pressure gauge is set too high, it will affect the relative error of the indicated value. ( ) 94. If the maximum scale value of a pressure gauge is set too high, it will affect the accuracy of the gauge. （ ） 95. The accuracy of float-type level gauges or other devices that measure the liquid level indirectly is higher than that of glass tube or glass wall plate level gauges, or devices that allow direct observation of the liquid level. ( ) 96. The principle of level indication in a rotating tubular level gauge is the same as that in a sliding tube level gauge. ( ) 97. Thermometer interfaces are of two types: those with protective sleeves and those without such sleeves. Thermometers with protective sleeves may cause delays in the measurement values. ( ) 98. The temperature measurement device is a composite unit. It consists of a temperature-sensitive element, an interface, and an indicator gauge. ( ) 99. The accuracy class of a pressure gauge is determined by the percentage of its allowable error relative to the scale values on the gauge face; the higher the accuracy class, the greater the percentage of the allowable error relative to the maximum scale value. （ ） 100. The larger the range of a pressure gauge, the greater the allowable absolute error in the pressure values it measures, for pressure gauges of the same accuracy class. ( ) 101. Changing the operating conditions of a vehicle-mounted tank does not require replacing the safety accessories. ( ) 102. During loading and unloading operations, the operators and drivers must remain at the site, but the escorts may leave. ( ) 103. For road tankers filled for the first time after maintenance, the oxygen content inside the tank shall not exceed 3%. ( ) 104. Glass plate level gauges can be used in road tankers. ( ) 105. The resistance at the connection between the valve and the vehicle chassis should not exceed 10 mΩ. ( ) 106. During loading and unloading operations, the cross-sectional area of the grounding wires connecting the tank to the ground-mounted equipment should be no less than 5.5 mm2. ( ) 107. The rated working pressure of the hoses used for loading and unloading in truck-mounted tanks must be no less than twice the highest working pressure of the loading and unloading system. ( ) 108. Each side of the transport tank vehicle should be equipped with a dry powder fire extinguisher weighing more than 5 kg, or a 1211 fire extinguisher weighing more than 4 kg. ( ) 109. The colored ring on a liquefied gas road tanker can indicate the type of medium contained within it. ( ) 110. The symbol color on liquefied petroleum gas road tankers is the bright red color associated with flammable and explosive gases. （ ） 111. For the convenience of loading and unloading, filling pumps can (cannot) be installed on liquefied gas road tankers. ( ) 112. The opening pressure of the safety valve on low-temperature vehicle tankers must not exceed the design pressure of the tank. ( ) 113. Low-temperature liquid storage tanks can also be used if the pressure gauge dial does not have a red line indicating the maximum operating pressure. ( ) 114. Cryogenic liquid storage tanks that show obvious damage upon visual inspection and require further examination cannot be used. ( ) 115. When filling or handling liquid oxygen, it is strictly prohibited to wear work clothes and personal protective equipment that are contaminated with grease. ( ) 116. The new safety valve for low-temperature liquid storage tanks can be used without any adjustment. ( ) 117. When the operating conditions of a low-temperature liquid storage tank are changed (pressure, temperature, medium, purpose, etc.), the entity using the pressure vessel shall bring the design documents related to these changes, the approval documents, as well as the \"Pressure Vessel Operation Registration Form\" and inspection reports to the special equipment supervision agency under the quality and technical supervision department responsible for registration, in order to go through the procedures for making such changes. ( ) 118. Operators of cryogenic liquid storage tanks should be familiar with the relevant provisions of the \"Regulations on Safety Supervision of Pressure Vessels\", as well as the characteristics and hazards of cryogenic liquids. ( ) 119. Within 5 meters of the storage, vaporization, filling, and usage areas of low-temperature liquid tanks, there shall be no openings leading to lower areas such as basements, air-raid shelters, ditches, etc ； The gutter should have a liquid barrier. ( ) 120. Low-temperature liquid storage tanks installed outdoors can still operate normally even in the absence of static discharge and lightning protection devices. ( ) 121. The pressure gauges and safety valves on the liquid oxygen tank can be used without the need for degreasing. ( ) 122. After the operator releases liquid oxygen, which evaporates to form gaseous oxygen, this oxygen can be absorbed by fabrics such as clothing, and it can easily cause combustion hazards when exposed to a fire source. ( ) 123. The location where low-temperature liquid storage tanks are installed must have good ventilation conditions or ventilation systems, as well as the ability to discharge substances safely. ( ) 124. When low-temperature liquid oxygen tanks are installed indoors, large amounts of gas and liquid can be released into the room. （ ） 125. When low-temperature liquid nitrogen and liquid argon storage tanks are installed indoors, large amounts of gas and liquid can (cannot) be released into the room. ( ) 126. When the valves, instruments, and pipes of low-temperature liquid storage tanks become frozen and blocked, they can be thawed using an open flame. ( ) 127. When initially filling a cryogenic liquid tank, the valves should be opened slowly to prevent excessive pressure buildup that could lead to overpressure. ( ) 128. When the liquid oxygen in the storage tank has not been completely drained, welding repairs can be carried out in order to speed up the maintenance process. ( ) 129. New operators of cryogenic liquid storage tanks, who have not undergone assessment and do not possess a safety operation certificate, can occasionally operate independently when there is a shortage of staff. ( ) 130. In areas where oxygen is stored, vaporized, filled, or used, open flames must be strictly prohibited within a radius of at least 5 meters from the area where liquid oxygen vaporizes; all sources of fire must be eliminated, and clear no-fire signs must be in place. ( ) 131. The fill level of low-temperature liquid storage tanks shall not exceed 0.95; overfilling is strictly prohibited. ( ) 132. The inner tank and vacuum jacket of low-temperature storage tanks do not need to undergo pressure testing for twenty years. ( ) 133. When the vacuum level in the vacuum jacket of the vacuum powder low-temperature storage tank drops to 65 Pa, the evaporation rate increases, which is not economical; therefore, the vacuum needs to be restored. ( ) 134. Hydrogen, ethane, carbon monoxide, and methane are flammable gases. ( ) 135. Ammonia, hydrogen chloride, carbon monoxide, and chlorine are toxic gases. ( ) 136. Chlorine and hydrogen chloride are corrosive gases. （ ） 137. A liquid substance has a certain volume as well as a certain shape. ( ) 138. Gases have a low density and are highly compressible. ( ) 139. The higher the pressure, the lower the liquefaction point of a gas. ( ) 140. Safety signs include prohibition signs, warning signs, instruction signs, and guidance signs. ( ) 141. Liquid oxygen or liquid nitrogen can also be filled into containers made of carbon steel. ( ) 142. Gases with a critical temperature greater than 70 °C are called high-pressure liquefied gases. ( ) 143. Acetylene in the liquid oxygen storage tank must be analyzed at least once a month. ( ) 144. **Standard for High-Purity Nitrogen**: The purity of nitrogen in gaseous and liquid form that meets the specifications is not less than 99.9%. ( ) 145. Mechanical emergency shut-off devices operate by using a handle to open the emergency shut-off valve; the valve closes again when the handle is released ； The hydraulic emergency shut-off device is operated by using a hand pump to generate pressure, which is then transmitted through the oil circuit to open the emergency shut-off valve. In the event of an accident, by opening the hand pump or the pressure relief valve located at the rear of the vehicle, the emergency shut-off valve closes. ( ) 146. Metal equipment and accessories at LPG storage and production sites must be equipped with reliable grounding, and the grounding resistance of such grounding systems shall not exceed 10 ohms. ( ) 147. Operators at LPG storage and production sites must wear anti-static protective equipment while working; in hot weather, they may operate with their hands and arms exposed. ( ) 148. A autoclave is one of the most common types of pressure vessels with quick-opening doors; it has strict safety interlock requirements regarding the opening and closing of the lid and the vessel body – steam must be introduced while the door is closed, and the door must be opened after steam has been released – in order to ensure the safe operation of the pressure vessel. ( ) 149. The vapor barrier and drainage device, which is one of the main components of a autoclave, functions to remove the condensed water inside the vessel during operation, thereby reducing the additional stresses caused by temperature differences. It is an essential safety accessory for autoclaves. ( ) 150. The supports used to hold the autoclave should all be secured with foot bolts in order to ensure the safe operation of the equipment. ( ) 151. Steam should be introduced into the autoclave in a uniform manner by using steam distribution pipes arranged along the length of the vessel, so as to ensure even heating throughout the vessel and prevent deformation. ( ) 152. The vapor-proof drainage devices connected to the bottom of the autoclave via pipes are usually drainage tanks, equipped with traps, drain valves, etc. It is required that the water level alarm device be sensitive and reliable during operation, and that the drain valves and steam traps function properly. It should be noted that strainers are prone to clogging, so they need to be inspected and cleaned regularly. ( ) 153. When using an acetylene cylinder, measures should be taken to prevent it from being exposed to direct sunlight or heat; it is strictly prohibited to heat the acetylene cylinder with hot water at 60°C or above or any other heat source. ( ) 154. When using an acetylene cylinder, a dedicated pressure regulator and flashback arrestor must be installed at the outlet of the cylinder valve. Under normal use, the exhaust pressure indicated by the pressure regulator shall not exceed 0.15 MPa, and the exhaust flow rate shall not exceed 0.05 m3/h·L. For higher flow rates, multiple acetylene cylinders should be connected together to supply gas. ( ) 155. Before filling an acetylene cylinder, it is necessary to determine the amount of solvent that needs to be added in accordance with GB13591 \"Regulations for Filling Dissolved Acetylene\". After adding solvent to the acetylene cylinder, it is necessary to verify the amount of solvent inside the cylinder. ( ) 156. Before filling an acetylene cylinder, the filling facility must have dedicated personnel to inspect the cylinder; the results of such inspections should be recorded in the filling report, with the inspector signing it. ( ) 157. After filling, acetylene cylinders must meet the following requirements: ( ) (1) The amount of acetylene filled and the pressure inside the cylinder after 6 hours of standing must comply with the provisions of the relevant **standards ； (2) There shall be no leaks or other abnormal phenomena. Acetylene cylinders that do not meet the above requirements must not be released from the factory and should be disposed of properly. 158. Gas cylinders shall be equipped with guards to protect the cylinder valves, and the connection between the cylinder and the guard shall be of a welded structure. ( ) 159. The arrangement and content of the markings on gas cylinders shall comply with the regulations set out in the Gas Cylinder Safety Supervision Rules. The markings on the gas cylinder should be permanent. ( ) 160. For the in-use YSP-0.5, YSP-2.0, YSP-5.0, YSP-10, and YSP-15 types of liquefied petroleum gas cylinders, the inspection cycle is 3 years from the date of manufacture. ( ) 161. The regular inspection items for liquefied petroleum gas cylinders include: visual inspection, wall thickness measurement, hydrostatic test, or measurement of residual deformation rate. ( ) 162. LPG cylinders with a depression depth exceeding 10 mm or equal to 1/10 of the short diameter of the depression need to be repaired. ( ) 163. Cylinders with isolated pitting corrosion on their LPG cylinders, where the remaining wall thickness is less than 2/3 of the designed wall thickness, should be scrapped. ( ) 164. The valve on liquefied petroleum gas cylinders must be fitted securely, ensuring an adequate number of threads for a proper connection with the valve seat as well as good sealing performance; after installation, at least 3–4 threads should be visible. ( ) 165. After inspection, cleaning, and component replacement, the liquefied petroleum gas cylinder valves are tested one by one for their airtightness in the closed state, during the opening and closing process, and in the fully open state. The test pressure is 2.5 MPa, with a holding time of no less than 3 minutes; any leakage is not permitted. ( ) 166. For liquefied petroleum gas cylinders that are newly put into use or filled with gas for the first time after internal inspection, the air inside the cylinders must be removed in accordance with regulations before filling, and filling may only take place after the air has been verified to be of suitable quality through analysis. ( ) 167. Workers in the production roles at filling stations must undergo professional training and assessment, and hold valid certificates to work in these positions. ( ) 168. For tasks such as filling cylinders at LPG filling stations, operating tank areas, loading and unloading tank trucks, and introducing liquid into pipelines at receiving stations, at least 5 people must be present during these operations. ( ) 169. Filling stations should be equipped with trained personnel for inspecting pressure vessels, cylinders, tank trucks, as well as personnel for repairing accessories. ( ) 170. Filling stations should be equipped with safety officers, and those that supply more than 5,000 tons of liquefied gas per year should have a safety management team. ( ) 171. Liquefied petroleum gas cylinders filled upon entry must comply with the provisions of GB5842 or GB15380, and shall be within the inspection cycle specified in GB8334. ( ) 172. A valve that integrates a filling device, an 80% charge limit device, a safety valve, a shut-off valve, a flow control valve, and a liquid level display device, and is installed on liquefied petroleum gas cylinders for motor vehicles that have only one opening; hereinafter referred to as an integrated valve. ( ) 173. Bottle valves must be disassembled one by one for inspection, cleaned, and any damaged parts replaced, to ensure smooth operation without leakage. ( ) 174. For CNG refueling stations, the compressors used in the compression system are primarily piston compressors with a rod mechanism. ( ) 175. Function of a safety valve: Any device that operates under certain pressure levels must, from a production process perspective, function at pressures that are not lower than its specified operating parameters. When the pressure drops below this specified value, the safety valve opens automatically to release gas ； When the gas pressure rises to a certain level, the safety valve closes automatically; therefore, it is a device that provides automatic protection. ( ) 176. Gas stations are areas of high fire risk; smoking is strictly prohibited inside them, as is the stacking of miscellaneous items or the storage of any flammable or explosive substances. ( ) 177. The vehicle must be turned off while refueling, the handbrake must be engaged, and all electrical devices in the vehicle must be turned off; it is strictly prohibited to start the engine while refueling. ( ) 178. At a constant temperature, when a liquid is placed in a sealed container, the gas phase and the liquid phase are in dynamic equilibrium when the number of molecules that change from liquid to gas per unit time is equal to the number of molecules that change from gas to liquid. The pressure exerted by the saturated vapor at this point is known as the saturated vapor pressure. ( ) 179. The magnitude of the saturated vapor pressure depends only on the temperature of the liquid. ( ) 180. The phenomenon in which a substance suddenly changes from one state to another, producing intense sound and light along with the release of large amounts of energy, is called combustion. ( ) 181. The concentration range within which a mixture of flammable gases or vapors and air can explode and burn when exposed to an ignition source is known as the explosive concentration limit. ( ) 182. A container with a working pressure of 0.1 Mpa does not qualify as a pressure vessel. ( ) 183. The pressure gauge installed in a pressure vessel system should have a red line drawn on its glass panel as a warning mark at that location. ( ) 184. The \"Regulations on Safety Technical Supervision of Pressure Vessels\" classify pressure vessels into three categories: Class I, Class II, and Class III, in order to facilitate safety technical supervision and management. ( ) 185. Counterbalance scales are commonly used for the weighing of liquefied petroleum gas. （ ） 186. The pressure in a tank used for storing liquefied gas depends on the saturated vapor pressure of the liquefied gas stored there at that storage pressure ( ). 187. The \"Regulations on Safety Inspection of Pressure Vessels\" specify that these regulations apply to pressure vessels in which liquefied gases are stored ( ). 188. The property whereby a scale can return to its original balanced position after several swings once its indicating part’s balanced state is disrupted is called sensitivity. ( ) 189. The three necessary conditions for combustion are a combustible material, an oxidizing agent, and a heat source. ( ) 190. The main components of liquefied petroleum gas are propane, propylene, butane, and butylene. ( ) 191. The Regulations on Safety Inspection of Pressure Vessels stipulate that the dial diameter of pressure gauges used in pressure vessels should generally be no less than 100 mm. ( ) 192. To prevent static electricity, liquefied petroleum gas pipelines are required to have an earth resistance of not less than 100 ohms, with the bridging resistance between flanges being no more than 0.03 ohms. ( ) 193. The typical explosion limit for liquefied petroleum gas is 10–20%. ( ) 194. Liquefied petroleum gas is lighter than water, so fires involving liquefied petroleum gas can be extinguished with water. ( ) 195. Liquefied petroleum gas releases heat when it vaporizes ； Heat is absorbed during liquefaction. ( ) 196. The saturated vapor pressure of liquefied petroleum gas is related to its composition and temperature ； And it has nothing to do with the size of the container or the amount of liquid. ( ) 197. The actual air volume required for liquefied petroleum gas is 3 times that of natural gas, and 5 times that of artificial gas. ( ) 198. Vane pumps increase the flow of liquid by taking advantage of changes in pressure during operation. ( ) 199. Globe valves can shut off fluids as well as regulate flow rates. ( ) 200. The safety valve automatically releases excess pressure when it exceeds the maximum allowable level, thereby protecting the pipelines and equipment. ( ) 201. The \"Regulations on Safety Supervision of Gas Cylinders\" specify that the filling factor for filling mixed liquefied petroleum gas is 0.42. ( ) 202. The basic methods of extinguishing fires include isolation, smothering, cooling, and suppression. ( ) 203. The fire extinguishers used at LPG stations mainly include dry powder fire extinguishers and 1211 fire extinguishers. ( ) 204. The paint color, markings, text color, and color rings of steel seamless gas cylinders shall comply with the relevant provisions of GB7144. ( ) 205. The color of compressed natural gas cylinders for vehicles is brown; the inscription “Natural Gas” is in white color. Other requirements shall comply with GB7144. ( ) 206.GB16804 stipulates that the attaching and replacement of gas cylinder labels must be carried out by the gas cylinder filling unit. Labels should be attached to each gas cylinder at the time of its first filling. If it is found that the label is detached, torn, damaged, or the printing is unclear, the filling unit shall promptly supply a replacement label or replace it. ( ) 207. For dissolved acetylene cylinders and liquefied gas cylinders, the filling records must be kept for at least one year. ( ) 208. Regulations for filling permanent gas cylinders require that the filling records be kept for at least one year. ( ) 209. Personnel at filling stations that fill toxic liquefied gases must wear appropriate gas masks based on the toxicity of those gases; in addition, a dedicated person should be assigned to regularly inspect and replace these gas masks. ( ) 210. Personnel at filling stations that fill containers with flammable gases should wear anti-static clothing and shoes without metal studs, and should avoid using maintenance tools that may generate sparks. （ ）I. True or False Questions: 1.（√）2.（√）3.（√）4.（√）5.（√）6.（√）7.（√） 8.（√）9.（√）10.（√）11.（√）12.（√）13.（√）14.（√） 15.（×）16.（×）17.（√）18.（√）19.（√）20.（×） 21.（√）22.（×）23.（√）24.（√）25.（√）26.（√）27.（√） 28.（×）29.（√）30.（√）31.（√）32.（√）33.（×）34.（√） 35.（×）36.（×）37.（√）38.（√）39.（√）40．（√）41.（×）42.（√）43. ( √ ) 44.（√）45.（×）46.（×）47.（√）48.（√）49.（×）50.（√）51.（√）52.（√）53.（√）54. （√）55.（√）56（×）57.（√）58（√）59.（×）60.（√）61.（×）62.（√）63.（√）64.（√）65.（×）66.（×）67.（×）68.（√）69（√）70.（√）71.（×）72.（×）73.（√）74.（√）75.（√）76.（×）77.（√）78.（√）79.（√）80.（√）81.（√）82.（√）83.（√）84.（×）85.（√）86.（×）87.（×）88.（×）89.（√）90.（×）91.（×）92.（√）93.（√）94.（×）95.（×）96.（√）97.（√）98.（√）99.（×）100.（√）101.（×）102.（×）103.（√）104.（×）105.（√）106.（√）107.（×）108.（√）109.（√） 110.（√）111.（×）112.（√）113.（×）114.（√）115.（√） 116.（×）117.（√）118（√）119.（√）120.（×）121.（×） 122.（√）123.（√）124.（×）125.（×）126.（× ）127.（√） 128.（×）129.（×）130.（√）131.（√）132.（×）133.（√） 134.（√）135.（√）136.（√）137.（×）138.（√）139.（×） 140.（√）141.（×）142.（×）143.（√）144.（×）145.（√） 146.（√）147.（×）148.（√）149.（√）150.（×）151.（√） 152.（√）153.（×）154.（√）155.（√）156.（√）157.（×） 158.（√）159.（√）160.（×）161.（×）162.（×）163.（√） 164.（×）165.（×）166.（√）167.（√）168.（√）169.（√） 170.（×）171.（√）172.（√）173.（√）174.（√）175.（× ） 176.（√ ）177.（√ ）178.（√ ）179.（×）180.（× ）181.（√ ） 182.（×）183.（×）184.（√ ）185.（√ ）186.（√ ）187.（×） 188.（×）189.（√ ）190.（√ ）191.（√ ）192.（√ ）193.（×） 194.（×）195.（√ ）196.（√ ）197.（×）198.（√ ）199.（√ ） 200.（×）201.（√ ）202.（×）203 （√ ）204.（√ ）205.（√ ） 206.（√ ）207.（√ ）208.（×）209.（√ ）210.（√ ） The answers are for reference only.