One question per day 20170919(2) 75 facts on safety production techniques

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This post was last edited by Xiao Yu on September 19, 2017, at 12:42. There are rewards for correct answers and also for participating in the discussions. Let’s learn from the best practices in the “Brothers” section; everyone can improve through Q&A sessions and become more experienced by posting replies. Let’s share and spread safety knowledge! Here are 75 key points related to workplace safety techniques, excerpted from the “Coal Chemical Industry Safety Education Platform”. 1. Facilities such as warehouses for hazardous chemicals, hydrogen/oxygen stations, and fuel storage areas should be kept away from any sources of ignition. They should be located at the periphery of the plant area, on the upwind side relative to the direction in which winds blow least frequently. 　　2. After filling, the gas cylinder should be left to stand for (24) hours to allow the pressure to stabilize and the temperature to even out. 　　3. According to China’s standards, under normal operating conditions of electrical installations or equipment, the limit for 15–100HZ alternating voltage is (33) V in dry environments, and (16) V in humid environments. 　　4. The maximum allowable concentration of dust containing 10%-50% silica in workshop air is (2) MG/M3. 　　5. At the point where the power supply lines enter the building, the PE main conductor, the grounding main conductor, the main water pipes, the main gas pipes, as well as the vertical pipes for heating and air conditioning are connected to each other. It is also advisable to connect the building’s metal components and other metal pipes as well; this measure is known as (main equipotential bonding). 　　6. When low-voltage overhead lines pass through residential areas, the distance between the line conductors and the ground should not be less than (6) M. 　　7. The emergency switching time of fire emergency lighting fixtures should not exceed (5) S, while that of such fixtures used in highly hazardous areas should not exceed (0.25) S. 　　8. Explosive gas mixtures are classified into (6) groups according to (ignition temperature). 　　9. The fully enclosed vertical mesh used on the exterior of buildings should have a mesh density of not less than (2000) meshes/100 CM2. 　　10. The time-weighted average permissible concentration refers to the average allowable exposure level for an (8-hour) working day, with time used as the weighting factor. 　　11. During shunting operations, the speed while pushing forward shall not exceed (30) KM/H. 　　12. According to the \"Classification of Hazards in Operations Involving Productive Dusts,\" the degree of hazard posed by dust is divided into 5 levels. The criteria for this classification are the content of free silica in the dust, the multiple by which the dust concentration exceeds the permissible level, and the total lung ventilation volume of workers exposed to the dust. 　　13. Electromagnetic radiation refers to the hazards caused by energy radiation in the form of electromagnetic waves. Radiative electromagnetic waves refer to electromagnetic waves with a frequency of over 100 KHZ. 　　14. The high-voltage circuit breaker must be connected in series with the high-voltage isolating switch. 　　15. The secondary side of an AC arc welder should be connected to ground, mainly to prevent the danger and harm caused by high voltage leaking into the low-voltage circuit. 　　16. The essence of all fire prevention measures is to prevent the simultaneous existence and interaction of the basic conditions for combustion. 　　17. The main difference between combustion and chemical explosion lies in (the speed at which the substance burns). 　　18. The validity period for the registration of cylinder filling by cylinder filling units is (five years). 　　19. For dealing with simultaneous boiling of steam and water: it is necessary to reduce the combustion intensity, lower the load, and close the main steam valve; open the continuous blowdown valve fully and also open the periodic blowdown valve to drain water, while simultaneously adding water to improve the quality of the boiler water. Once the water quality improves and the water level becomes clear, normal operation can be gradually resumed. 　　20. The fail-safe structure does not have (intermittent operation mode). 　　21. Work involving high-temperature and intense thermal radiation refers to tasks carried out in environments where the temperature is 30 degrees Celsius or higher, or where the temperature is 2 degrees Celsius higher than the outdoor temperature during summer, along with exposure to strong radiant heat. 　　22. In evaluation monitoring, the optimal sampling period for the time-weighted average allowable concentration is (continuous sampling over 3 working days (shifts)), including the working day on which the concentration of harmful substances in the air is highest. 　　23. During the working week, the time when the concentration of harmful substances in the air is highest should be selected as the (key sampling day). 　　24. The safety principle of the protective grounding IT system is to limit (fault voltage) within a safe range. 　　25. The protection device is one of the important safety accessories in a boiler. To prevent explosions, explosion-proof doors are often installed on (the furnace chamber and flue). 　　26. The main characteristic of the early stage of a fire is (smoldering). 　　27. The general approaches to fire prevention are arranged in chronological order as (evaluation, flame retardancy, fire detection, fire extinguishing). 　　28. The likelihood of spontaneous combustion of coal is (higher) during the rainy season compared to the dry season. 　　29. The lifting capacity limiter is mainly used in (bridge-type) heavy machinery, with the main product being the (electrical type). 　　30. Electrical-type products generally consist of a load sensor and secondary instruments, with the load sensor being of the strain-gauge type or magnetostriptic type. 　　31. As a production tool that causes arm vibration, the wind shovel belongs to the category of impact tools. 　　32. In mechanical safety protection devices, photoelectric and inductive safety protection devices shall be equipped with alarm mechanisms to detect any issues related to hygiene and epidemic prevention. 　　33. Those that belong to external exposure protection are (containment and isolation, contamination prevention and cleaning), while those that belong to internal exposure protection are (time protection, distance protection, shielding protection). 　　34. A safety valve is an automatic pressure-relief valve that opens under the influence of the static pressure at the inlet; it can be divided into 9WG (full-opening safety valves and slightly-opening safety valves). 　　35. The adsorption method is commonly used for low-concentration harmful gases. 　　36. A (control valve, check valve) must be installed on the air inlet pipeline of the gas generator, and it should be flexible and reliable; an (explosion-proof valve, vent valve) should be installed at the end of the pipeline. 　　37. In a power system where one point (the neutral point) is directly grounded, the exposed conductive parts of electrical equipment are connected to the neutral point of the power system through a protective wire. This system is called the TN system. 　　38. In a power system where the neutral point is directly grounded, and the exposed conductive parts of electrical equipment are also directly grounded (independent of any grounding points in the power system), this is referred to as the TT system. 　　39. In a man-machine system with mechanical control, humans in such a system primarily serve as the (operators and controllers) of the production process. 　　40. **It belongs to organic dusts. 　　41. Dust particles with high dispersion typically carry a charge; when these particles have opposite electrical charges, it promotes agglomeration and accelerates sedimentation. 　　42. Bromine often exists in a gaseous state. 　　43. Batteries, safety isolation transformers, and independently powered diesel generators can be used as safe power sources. 　　44. The water-tube boiler belongs to the shell-and-tube boiler type. 　　45. Solid particles suspended in air with a diameter of less than 0.1 micrometers are (smoke). 　　46. CO2 is not suitable for the washing method. 　　47. The furnace must be shut down when the oxygen content in water gas and semi-water gas reaches 1%. 　　48. The use of (valve-type) arresters is the main measure to protect various power transformation and distribution installations from lightning intrusion waves. 　　49. Smoke exhaust windows belong to natural ventilation. 　　50. (Refining and processing) A low-expansion foam fire extinguishing system can be used. 　　51. In the basements of high-rise residential buildings, and in category II high-rise residential buildings with a height of no more than 32 meters that are not of the unit-type or corridor-type, (enclosed stairwells) should generally be provided. 　　52. The (concentration) at which the combustible substances and oxidizing agents in baozha* react completely is, in theory, the content of combustible substances in the mixture during complete combustion. 　　53. The finished powdered emulsion has high (detonation) properties, and there is a possibility of the formation of explosive dust during its production process. 　　54. Based on the characteristics of the crane’s metal structure. Cranes can be divided into two main categories: bridge cranes and boom cranes. 　　55. The system also known as the rope model is a (parallel system). 　　56. The electrostatic method is a technique for purifying gases, in which particles become charged under the influence of an electric field; they then move toward the (precipitation electrode). When these charged particles come into contact with the (dust collection electrode), they lose their electrons and become neutral, thereby being captured and thus enabling gas purification. 　　57. The deformation of metal materials under tensile forces can be divided into (elastic deformation stage, plastic deformation, and fracture deformation). 　　58. Regarding both the dust explosion pressure and the rate of increase in dust explosion pressure, (dust particle size) has a much greater impact on the latter. 　　59. In the safety design of railway transportation, what is used to enhance the safety of transportation equipment is (automatic block signaling). 　　60. When shutting down a gas heating furnace, first close the gas valve, then the air valve, and finally the main valve. 　　61. Instruments in the acetylene station must be (digital) type instruments. 　　62. The temperature of the gas used for the airtightness test of pressure vessel doors made of carbon steel and low-alloy steel should be no lower than (5) degrees. 　　63. The most common types of mechanical injury accidents are (entanglement and crushing). 　　64. The safety principle of the protective zero system is (rapidly cutting off the power supply). 　　65. The grounding of the metal enclosures of electrical equipment in IT systems is (protective grounding). 　　66. In the TT system, the electronic equipment enclosure is connected to the low-voltage neutral point of the distribution transformer through (the ground resistance). 　　67. Isolated conductors must not be left in areas where there is a risk of static electricity. 　　68. To determine the degree of extinguishment of spontaneous combustion, (CO, ethylene, acetylene) are used. 　　69. Loading and unloading bridges and gantry cranes with a span of 40 meters or more shall be equipped with skew adjustment and display devices. 　　70. (Eddy current testing) can not only detect defects but also reveal dimensional changes and material properties. 　　71. When filling acetylene cylinders, the filling pressure must not exceed 2.5 MPa, and the volumetric flow rate of the gas being filled should be less than 0.015 m3/(h·L). 　　72. The pressure condition used to classify pressure vessels refers to (design pressure). 　　73. The number of closed cars included in the freight train shall not exceed (6%) of the total number of cars. 　　74. On electrified railways, boundary posts should be installed on both sides of the level crossing, with a clearance not exceeding 4.5m after adjustment. 　　75. Buses with more than (9) seats and vehicles carrying flammable materials shall be equipped with fire extinguishers.