Call for submissions with rewards: safety operating procedures for various chemical hazard storage tanks

1) Safety technical operating procedures for the installation of horizontal tanks: ① Before installing the tank, a settlement test should be conducted on the tank foundation to ensure its stability and prevent the tank from shifting. ②If the tank is installed on two saddle supports, one of the supports should be a fixed end while the other is a movable end, allowing the tank to expand and contract freely with temperature changes. The liquid phase tube on the tank should be installed near the fixed end. ③The tank should be installed at an angle sloping downward toward the end with the liquid phase pipe, with a slope of 0.01–0.02, and a drain valve should be installed at the lowest point of the tank. ④The control valve of the spraying device should be located far away from the storage tank, to ensure that it can still be opened in a timely manner in the event of a fire that prevents access to the tank area.** ⑤Vent pipes should preferably be installed in a centralized manner, with the discharge height being no less than 5 meters. A bend or rain cap should be installed at the upper end of the vent pipe to prevent water from accumulating inside it. (2) Safety technical operating procedures for spherical tank installation: ① If the tank body is supported by equatorial tangent pillars, there should be no relative movement in either the vertical or horizontal direction of the pillars, and uniform settlement must be ensured. The pillar should be equipped with an anti-static grounding device, a fire and heat insulation layer, and gas exhaust outlets inside the pillar. ②The highest and lowest points of all tie rods between the various pillars must be at the same elevation. The intersection point of two tie rods is considered a vertical intersection, and it must not be welded in place. ③The annular **pipes of the spraying device are arranged in different parts of the spherical tank, and must be able to distribute water evenly over all areas of the tank body and its supports. ④The spraying device shall have its own separate water supply system, with a continuous water supply duration of at least 20 minutes, and it shall be operable from a safe location at a distance of more than 5 meters from the spherical tank. ⑤After the spherical shell is installed, the allowable deviation of its inner diameter shall not exceed ±0.35% of the specified inner diameter ； The ellipticity shall not exceed 0.7% of the specified inner diameter, and shall not be greater than 80 mm. ⑥When welding locally on the spherical shell (including welding accessories for installation on it), the welding process and welding materials shall be the same as those used for normal welding of the spherical shell. It is prohibited to use forceful methods such as hammering to remove lugs, fixtures, etc.; any weld scars remaining after removal must be polished smooth. (3) Safety Technical Operating Procedures for Tank Inspections ① Inspection Cycle: The regular inspections of tanks are divided into external inspections, internal and external inspections, and comprehensive inspections. The inspection cycle should be determined as appropriate based on the technical condition of the equipment and its operating conditions; however, external inspections must be carried out at least once a year, internal and external inspections at least once every 3 years, and comprehensive inspections at least once every 6 years. If the storage tank has been in use for 15 years, internal and external inspections should be carried out every two years ； If the service life has reached 20 years, internal and external inspections should be carried out at least once a year. For storage tanks that have undergone regular inspections, the inspector prepares an inspection report indicating whether the tank can continue to be used or whether special monitoring measures are required. The inspection report shall be filed in the technical archive of the storage tank. ②Preparatory work before inspection: a. Review relevant technical documents to understand the defects that have been identified during the manufacturing, installation, and use of the storage tank. b. Drain all the medium from inside the storage tank, isolate the equipment and pipelines connected to it using blind flanges, and provide clear isolation markings. c. Perform displacement and cleaning of the residual gas in the storage tank, and take samples for analysis to ensure they meet safety standards. d. Open all manholes of the storage tank, remove the internal components of the tank, and clean the inner walls of any dirt. e. Cut off the power supply related to the storage tank. When entering the tank for inspection, low-voltage explosion-proof lamps with a voltage not exceeding 12V or 24V should be used, and there must also be a dedicated person monitoring from outside the tank. When the supply voltage of testing instruments and repair tools exceeds 36V, well-insulated flexible cables and reliable grounding wires must be used. f. The tank area should be equipped with fire-fighting, safety, and first-aid facilities. If hot work is required, the necessary approval procedures for hot work must be followed. ③Inspection contents a. Main contents of external inspection 1) Whether the anti-corrosion coating, insulation layer of the storage tank, and equipment nameplates are in good condition. 2) Check whether there are any abnormal phenomena on the outer surface of the storage tank, such as cracks, deformation, or local overheating. 2) Check for leaks in the nozzle welds of the storage tank, pressure-bearing components, etc. 4) Are the safety accessories and control devices complete, sensitive, and reliable? 5) Check whether the fastening bolts are in good condition, and whether there are any abnormalities such as settlement or tilting of the foundation. b. Main contents of internal and external inspections 1) All items of external inspection. 2) Check whether there is any media corrosion or erosion wear on the inner and outer surfaces of the storage tank as well as at the openings and nozzles. 3) Check whether there are any fractures or cracks in all welds of the storage tank, the head transition areas, and other stress-concentrated areas. 4) When corrosion or similar phenomena occur on the inner and outer surfaces of the tank, multiple wall thickness measurements should be taken at the suspected areas. If the measured wall thickness is less than the minimum design wall thickness, a re-evaluation of the strength should be conducted, along with recommendations regarding whether continued use is feasible and what the maximum allowable operating pressure should be. 5) When the inner wall of the tank has defects such as decarburization, stress corrosion, intergranular corrosion, and fatigue cracks, metallographic testing and surface hardness measurement shall be carried out, and a test report shall be prepared. c. Main contents of the comprehensive inspection: 1) All items of internal and external inspections. 2) Conduct random non-destructive testing on the main welds or the shell; the length of the area subject to such testing shall be 20% of the total length of the container’s welds or 20% of the surface area of the shell. 3) After passing internal and external inspections, a hydrostatic test is carried out at 1.25 times the design pressure of the storage tank, and an airtightness test is conducted at the design pressure of the storage tank. During the aforementioned tests, the absence of leaks in the storage tank and its welds, as well as no visible abnormal deformation of the tank, were considered acceptable.

Safety Operating Procedures for Metering Tanks and Storage Tanks: 1. Operators must be familiar with the structure of the storage tanks (metering tanks) being used, as well as the chemical properties of the materials stored therein, and with basic knowledge of first aid measures. II. The following checks must be performed before feeding: 1. Whether the valves are in good condition and whether they open or close correctly ； 2. Whether the level gauge and protective cover are in good condition, and whether the level indication is accurate, sensitive, and reliable ； Prevent false level indications caused by inaccurate level gauges ； 3. Are the electrical switches of the material feeding pump in good condition, sensitive, and reliable? ； 4. If compressed gas is used for pressing, check whether the pressure gauge is sensitive and reliable. III. Before each feeding, it is necessary to contact the relevant departments and personnel, and cooperation should be provided during the operation. IV. When performing pressure testing with corrosive or toxic materials, it is necessary to wear appropriate protective equipment, especially to protect the eyes; prevent the materials from entering the mouth or coming into contact with the skin. One should also stand in a safe location to monitor the liquid level, and the maximum loading capacity should not exceed 85% of its volume. V. When the material stored in the storage tank (measuring tank) is flammable and explosive, the wrenches used to operate the valves should be made of copper or alloy; it is not allowed to use iron tools for striking them. VI. Use a pressing device; when applying pressure, it is essential to ensure that it does not exceed the specified limit. After pressing is complete, the vent valve should be opened carefully. VII. Storage tanks (metering tanks) and their safety accessories must be regularly inspected and calibrated. The pressure gauge should be calibrated at least once every six months, while the safety valve should be calibrated at least once a year. 8. Before carrying out maintenance on storage tanks (measuring tanks), the contents inside must be completely removed. At the same time, it is necessary to strictly comply with the relevant provisions in the \"Safety Maintenance Procedures\" and obtain an \"Entry Permit for Container Operations\" before proceeding with the maintenance work.