Detailed Explanation of Safety Design and Operation Specifications for Storage Tanks

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Currently, it is a critical period for addressing the hazards in our plant’s tank areas. The author often finds it difficult to carry out hazard inspections and review remediation plans due to a lack of thorough understanding of relevant standards and regulations, feeling greatly inadequate in terms of professional knowledge. At the same time, during internal audits, external audits, and **various levels of inspections, different people have differing opinions as to whether a certain standard should be applied or which standard should be used. This leads to issues such as insufficient standards in the management of potential hazards in storage areas, as well as the need for further treatment after initial repairs, resulting in additional investment costs ； To facilitate the identification of potential hazards by comparing them against relevant standards and specifications, to provide a quick reference for formulating hazard mitigation plans, to assist in decision-making, and to improve the overall level of hazard management, the author has compiled and excerpted the key provisions related to storage and handling workshops from various standards and specifications. These include the “Construction Standards for Petroleum Product Storage Tanks” issued by China National Petroleum Corporation in August 2010; the “Safety Technical Specifications for Anti-Static Measures” (Q/SY1431-2011), which came into effect on July 1, 2011; the “Design Code for Petroleum Storage Tanks” (GB 50074-2014) issued by the Ministry of Housing and Urban-Rural Development on May 1, 2015; the “Fire Protection Design Code for Petrochemical Enterprises” (GB50160-2008), effective as of July 1, 2009; the “Technical Specifications for Anti-Seepage Measures in Petrochemical Projects” (GB/T 50934), implemented on June 1, 2014; the “Design Code for Foam Fire Extinguishing Systems” (GB 50151-2010), effective since June 1, 2011; the “Technical Specifications for Water Spray Fire Extinguishing Systems” (GB 50219-2014), implemented on August 1, 2015; the “Design Code for Fire Dikes in Tank Farms” (GB 50351-2014); and the “Design Code for Detection and Alarm Systems for Flammable and Toxic Gases in Petrochemical Industries” (GB 50493-2009). These provisions are intended as a reference for personnel working in tank farms. In cases where certain details are not covered here, the specific provisions outlined in the relevant standards and specifications shall prevail. 1. Scope of application: As stipulated in the general provisions of the \"Construction Standards for Finished Oil Depots\" (2010 edition), these standards were formulated in order to regulate the construction of finished oil depots owned by China National Petroleum Corporation. They aim to standardize design requirements, visual identity, selection of equipment and materials, as well as signage, thereby achieving \"standardized design, centralized procurement, modular construction, and standardized management.\" They also help to determine appropriately the scale of depot construction, the level of construction required, and the investment needed for such projects. According to the General Provisions of the \"Code for Design of Oil Depots\" (GB 50074-2014) (wherever the source is not specified herein, it refers to this code), this code applies to the design of newly built, expanded, and renovated oil depots ； Not applicable to: storage and transportation facilities for flammable and combustible liquids within petrochemical plant complexes, and standalone liquefied hydrocarbon storage tanks. According to the general provisions in the “Code for Fire Protection Design of Petrochemical Enterprises” (GB50160-2008): This code applies to the fire protection design of new construction, expansion, or renovation projects in petrochemical enterprises. According to the general provisions of the “Technical Code for Anti-seepage in Petrochemical Engineering” (GB/T 50934): This code applies to the design, construction, and quality inspection related to anti-seepage measures in petrochemical and coal chemical engineering projects ； It is not applicable to the storage, disposal, and landfilling of general industrial solid wastes and hazardous wastes, nor to the installation of long-distance pipeline systems. According to the general provisions in the “Code for Design of Foam Fire Extinguishing Systems” (GB 50151-2010): This code applies to the design of foam fire extinguishing systems installed in new construction, renovation, and expansion projects. According to the general provisions in the “Technical Code for Water Spray Fire Extinguishing Systems” (GB 50219-2014): This code applies to the design, construction, acceptance, and maintenance management of water spray fire extinguishing systems installed in new construction, renovation, and expansion projects. According to the general provisions in the “Code for Design of Fire Dikes in Storage Tank Areas” (GB 50351-2014): This code applies to the design of fire dikes and fire walls in new construction, renovation, and expansion projects of above-ground liquid storage tank areas. According to the general provisions of the \"Code for Design of Detection and Alarm Systems for Flammable and Toxic Gases in Petrochemical Industries\" (GB 50493-2009), this code is applicable to the design of detection and alarm systems for flammable and toxic gases in new construction, expansion, and renovation projects in petrochemical enterprises. According to the scope specified in the \"Technical Specifications for Anti-static Safety\" (Q/SY 1431-2011), this standard applies to the anti-static protection of equipment and facilities such as production units, storage tank areas, platforms, and docks in the enterprises under China National Petroleum Corporation. 2. Basic Provisions 2.1 Classification of Oil Storage Facilities Oil storage facilities are classified into 6 grades; the “Special Grade” has been added compared to previous standards, as shown in Table 1: Table 1 Classification of Oil Storage Facilities Grade Calculated total capacity of oil storage tanks, TV (m3) Special Grade 1,200,000 ≤ TV ≤ 3,600,000 Grade 1 1,000,000 ≤ TV < 1,200,000 Grade 2 300,000 ≤ TV < 1,000,000 Grade 3 100,000 ≤ TV < 300,000 Grade 4 100,000 ≤ TV < 100,000 Grade 5 TV < 100,000 As can be seen from the table above, the existing storage capacity of 344,000 cubic meters in the storage and handling facility corresponds to a Grade 1 oil storage facility. 2.2 Classification of fire hazards for flammable and combustible liquids
The fire hazards associated with flammable and combustible liquids are classified into three categories and six grades, as shown in Table 2:
Table 2: Classification of fire hazards for liquefied hydrocarbons, flammable, and combustible liquids stored in oil depots
Category | Characteristics or liquid flash point Ft (°C)
A | Hydrocarbon liquids and other similar liquids with a vapor pressure greater than 0.1 MPa at 15°C
B | Liquids other than those in category A, with Ft < 28
A | 28 ≤ Ft < 45
B | 45 ≤ Ft < 60
C | A | 60 ≤ Ft < 120
B | Ft > 120

2.3 Fire resistance ratings of buildings in oil depots
The minimum fire resistance rating for productive buildings (structures) within oil depots is shown in Table 3:
Table 3: Minimum fire resistance ratings for productive buildings (structures) in oil depots
Serial Number | Building (Structure) | Liquid Category | Fire Resistance Rating
1 | Pumps rooms for flammable and combustible liquids, valve rooms, fire pump rooms – Grade 2
2 | Laboratories, metering rooms, control rooms, cabinet rooms, power distribution rooms, tank supports/frames – Grade 2
3 | Railway tank car loading/unloading docks and shelters, road tank car loading/unloading platforms and shelters – Grade 3

3. Site selection
3.1 Safety distances between facilities in oil depots and larger buildings outside the depot
The safety distances between oil depots and large buildings or enterprises outside the depot are shown in Table 4:
Table 4: Safety distances between oil depots and residential areas, public buildings, industrial and mining enterprises, and transportation routes (m)
Serial Number | Name of oil depot facility | Oil depot grade | Name of building (structure) or facility outside the depot | Industrial and mining enterprise | Industrial enterprise | Railway line | Road
1 | Above-ground tank groups for Class A B and Class B liquids | Grade 1 | 60 | 35 | 25
2 | Railway or road tank car loading facilities for Class A B and Class B A liquids without oil and gas recovery systems ； Other Class A B and Class B liquid handling facilities: 1, 45, 26, 20, 3. Railway or road tank car loading facilities for Class B, Class C liquids, as well as those for Class A B and Class B A liquids equipped with oil and gas recovery systems: 1, 30, 18, 18, 3.2. Safe distance between storage tanks, handling facilities, and overhead cables: The safe distance between the storage tanks in oil depots and external overhead communication lines (or communication towers), as well as overhead power lines, should be no less than 1.5 times the height of the poles (towers) ； The safety distance between the railway tank cars and road tank trucks used for loading and unloading at oil depots, other facilities for storing flammable and combustible liquids, and overhead communication lines (or communication towers) as well as overhead power lines should be no less than 1.0 times the height of the pole (tower) ； The safety distance between the aforementioned facilities and overhead power lines with a voltage of not less than 35 KV shall be not less than 30 m. 4. Layout of the storage area
4.1 General layout of major buildings, structures, or facilities within the oil storage area
The layout of major buildings, structures, or facilities within each zone of the oil storage area should be organized by zones: tank farm, loading/unloading area for flammable and combustible liquids, auxiliary operations area, and administrative area. Specific details are shown in Table 5:

Table 5: Layout of major buildings, structures, or facilities within each zone of the oil storage area
| No. | Zone | Major buildings, structures, or facilities within the zone |
|-----|------|-----------------------------------------------------------|
| 1 | Tank farm | Groups of tanks, pumping stations for flammable and combustible liquids, substations, on-site cabinet rooms, etc. |
| 2 | Loading/unloading area | Railway loading/unloading area: railway trestles, pumping stations, surge tanks, substations, oil and gas recovery systems, etc.; Highway loading/unloading area: pumping stations, substations, truck loading/unloading facilities, control rooms, oil and gas recovery systems, etc. |
| 3 | Auxiliary operations area | Fire pump rooms, substations, warehouses, laboratories, computer rooms, diesel generator rooms, etc. |
| 4 | Administrative area | Office buildings, control rooms, dormitories for shift workers, bathrooms, canteens, etc. |

4.2 Fire separation distances between buildings, structures, and facilities within the oil storage area
The fire separation distances between buildings, structures, and facilities within the oil storage area (excluding distances between tanks) must not be less than those specified in Table 6:

Table 6: Fire separation distances between buildings, structures, and facilities within the oil storage area (in meters)
| No. | Name of building/structure/facility | Pump room | Highway loading/unloading facilities | Railway loading/unloading facilities | Fire pump room | Outdoor transformers | Substations | Control room | Perimeter fence of the storage area |
|-----|-----------------------------------|-----------|--------------------------------------|--------------------------------------|---------------|---------------------|-------------|--------------|------------------------------------|
| 1 | Floating roof tanks, V > 5000 | 15 | 20/15 | 20/15 | 26 | 25 | 25 | 38 | 11 |
| 2 | Floating roof tanks, V ≤ 5000 | 11 | 15/11 | 15/11 | 23 | 19 | 19 | 30 | 7.5 |
| 3 | Fixed roof tanks, V > 5000 | 20 | 25/20 | 25/20 | 35 | 32 | 32 | 50 | 15 |
| 4 | Fixed roof tanks, V ≤ 5000 | 15 | 20/15 | 20/15 | 30 | 25 | 25 | 40 | 10 |
| 5 | Pump rooms, Class B and Category A liquids | 12 | 15/15 | 8/8 | 30 | 15 | 15 | 30 | 10 |
| 6 | Highway loading/unloading facilities | 15/15 | — | 15/11 | 15/15 | 20/15 | 15/11 | 30/23 | 15/11 |
| 7 | Railway loading/unloading facilities | 8/8 | 15/11 | — | 15/15 | 20/15 | 15/11 | 30/23 | 15/11 |

Note: The fire separation distances listed in the table apply only to Class B and Category A liquids. For entries with two values, the first value refers to Class B liquids and the second to Category A liquids. 4.3 Fire protection distances between storage tanks 4.3.1 Fire protection distances between tanks in adjacent storage areas The fire protection distances between tanks in adjacent storage areas shall comply with the following requirements: For storage areas containing flammable and combustible liquids, the fire protection distance between adjacent tanks shall be not less than 1.0 times the diameter of the larger of the two tanks, and shall also be not less than 30 m. 4.3.2 Fire separation distance between tanks in adjacent groups within the same above-ground tank area: The fire separation distance between tanks in adjacent groups within the same above-ground tank area shall comply with the following requirements: The fire separation distance between fixed-roof tanks storing Class A and B liquids, as well as floating-roof tanks with inner floating roofs made of fusible materials, and tanks in adjacent groups shall be not less than 1.0 times the diameter of the larger tank among the adjacent tanks ； The fire separation distance between external floating roof storage tanks, internal floating roof storage tanks with steel floating roofs, and storage tanks in other tank groups shall not be less than 0.8 times the diameter of the larger tank among the adjacent tanks. 4.4 Other general layout requirements: The railway loading and unloading area should be located at the edge of the oil depot, and the railway tracks should not intersect with the roads leading to the entrances and exits of the oil depot ； The road loading and unloading area should be located on the side of the road outside the oil depot adjacent to it, and it is advisable to enclose it with a wall to separate it from other areas ； Pipelines and buried power lines unrelated to the tank farm shall not cross the fire dike. The following provisions are set for pump stations: Pump stations for Class A and Class B liquids shall be located outside the fire dike of above-ground vertical storage tanks ； When flammable and combustible liquid pumping stations are built in shed or open-air types, the distance between them and the storage tanks is not subject to any restrictions. 4.5 Circular fire lanes shall be provided in the road areas and storage tank areas of oil depots within the reservoir area ； Within the same circular fire lane, a fire-fighting clearance of at least 7 meters in width shall be maintained between the outer toe lines of the dikes surrounding adjacent tank farms ； The storage tank should be adjacent to at least one fire truck access road, and the distance from the center of the tank to each of the two fire truck access roads should not exceed 120 m ； When conditions are limited, the distance between the center of the tank and the nearest fire lane should not exceed 80 meters ； Fire lanes should be provided in the railway loading and unloading areas; they should run parallel to the railway loading and unloading tracks, and it is advisable that they form a circular route together with the roads within the warehouse. The distance between the fire lanes and the railway tank car loading and unloading tracks should not exceed 80 meters ； The elevation of the road surface for fire trucks surrounding the tank farm should be at least 0.5m, or more, higher than the designed elevation of the ground outside the fire dike ； The distance between the fire lane and the base line of the outer embankment of the fire dike should not be less than 3 m ； The width of the fire truck access roads in the tank storage area and loading/unloading area of a Class I oil depot should not be less than 9 m, of which the road surface width should not be less than 7 m ； The clear height of the fire truck access road should not be less than 5.0 m, and the turning radius should not be less than 12 m ； A turnaround area should be provided at the end of the fire lane ； Oil depots should be equipped with external roads connected to highways, the width of whose pavement should not be less than that of the fire access roads in the tank areas of oil depots of corresponding categories ； The oil depot should have no fewer than 2 vehicle entrances and exits leading to roads outside the depot, and these should preferably be located in different directions ； The tank farm should have no fewer than 2 vehicle entrances and exits, which should be located in different directions. Article 4.6.7 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that when the road surface is more than 2.5 m above the surrounding ground, and there are storage tanks and pipelines containing flammable liquids within 15 m of the road edge, protective structures such as guard posts or low walls should be installed at the edge of that section of road. Section 4.6.8 stipulates that pipe rack supports (edges), lighting poles, street trees, or sign posts should be at a distance of not less than 0.5m from the edge of the road surface. 4.6 In the reservoir area, the administrative management area, fire pump room, and main substation should be located in areas with relatively higher ground levels, or there should be measures in place to prevent flames from spreading to such areas in the event of an accident. 4.7 Enclosure wall for oil depots: A solid enclosure wall with a height of not less than 2.5 m should be installed around the oil depots. Fences should be installed between the administrative area and the tank area as well as the loading and unloading area. 4.8 Trees should not be planted between the greening fire lanes and the fire dikes of oil depots. 5. Tank area 5.1 Tank installation: Above-ground tanks should be made of steel ； Liquid chemical products of Classes A and B, as well as light naphtha, with a storage boiling point of not less than 45°C or a saturated vapor pressure at 37.8°C of not more than 88 kPa, should be stored in external floating roof tanks or internal floating roof tanks ； For storing crude oils of categories A and B, as well as refined oils, external floating roof tanks and internal floating roof tanks should be used ； When the maximum storage temperature of Jet A-3 is 5°C or less below the flash point of the fuel, fixed-roof storage tanks with a capacity of 10,000 m3 or less can be used ； External floating roof storage tanks should use steel single-disc or steel double-disc floating roofs ； The internal floating roof should be a metal internal floating roof; shallow-dish or open-compartment types of internal floating roofs are not permitted. Article 6.2.22 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that storage tanks equipped with steam heaters shall have measures in place to prevent the liquid from overheating. Section 6.2.24 stipulates that the feed pipe of the storage tank shall be connected at the lower part of the tank body ； If connected from the top, it should be extended to a distance of 200 mm from the bottom of the tank. 5.2 Tank layout: Class A and B liquid tanks can be arranged in the same tank group ； Boiling liquid storage tanks should not be arranged in the same group as non-boiling liquid storage tanks. 5.3 The total capacity of storage tanks within the same tank farm: The capacity of tank farms consisting solely of fixed-roof tanks, as well as those comprising a combination of fixed-roof tanks and external/internal floating roof tanks, shall not exceed 120,000 cubic meters ； The capacity of internal floating roof tank assemblies made of steel materials for floating roofs should not exceed 360,000 cubic meters ； The capacity of internal floating roof tank assemblies made of fusible materials for floating roofs should not exceed 240,000 cubic meters ； The capacity of external floating roof tank groups should not exceed 600,000 cubic meters. 5.4 For a group of tanks within the same tank farm, when the maximum capacity of any single tank is 10,000 cubic meters or more, the number of tanks should not exceed 12 ； When the maximum capacity of a single tank is 1,000 cubic meters or more, the number of storage tanks should not exceed 16 ； When the capacity of a single tank is less than 1,000 cubic meters, there is no limit on the number of storage tanks. Within the above-ground tank group, the tanks should not exceed 2 rows in height. 5.5 Tank foundations and fire separation distances between adjacent tanks within a tank farm, as well as leak prevention measures 5.5.1 Tank foundations and fire separation distances between adjacent tanks within a tank farm: The elevation of the foundation surface for above-ground vertical tanks should be at least 0.5 m higher than the designed ground level surrounding the tank. The fire separation distances between adjacent tanks within a tank farm are shown in Table 7: Table 7 Fire Separation Distances between Adjacent Tanks in Above-ground Tank Farms. Liquid category, Fixed-roof single-tank capacity, in m3, External floating-roof and internal floating-roof tanks, Horizontal tanks: ≤1000, ＞1000, ≥5000; Classes A B and B: 0.75D, 0.6D, 0.4D, 0.8m. Note: In the table, D refers to the diameter of the larger of the adjacent tanks. 5.5.2 Requirements for anti-seepage of storage tank foundations and the ground within tank farms
5.5.2.1 Anti-seepage requirements for storage tank foundations
Article 5.3.2 of the “Technical Code for Anti-Seepage in Petrochemical Engineering” (GB/T 50934) stipulates that the thickness of the high-density polyethylene (HDPE) membrane used as the anti-seepage layer for ring-wall type tank foundations should not be less than 1.5 mm ； Protective layers should be installed above and below the membrane; these protective layers can be made of filament non-woven geotextiles. A sand layer free of sharp particles can also be used as the protective layer beneath the membrane, with a thickness of not less than 100 mm ； The laying of high-density polyethylene (HDPE) membranes should proceed from the center slope outwards, with a slope of no less than 1.5%. Paragraph 5.3.3 stipulates that HDPE pipes should be used for the leakage pipes around the ring wall of the tank foundation. 5.5.2.2 Requirements for ground impermeability within tank groups: Clause 5.2 of the \"Technical Specifications for Impermeability Control in Petrochemical Projects\" (GB/T 50934) stipulates that the impermeable layer for the ground within tank groups can be made of clay, impermeable concrete, high-density polyethylene (HDPE) membranes, sodium-based bentonite waterproof blankets, or other materials with equivalent impermeability properties. If a clay impermeable layer is used, its top surface should be covered with a concrete floor or a layer of sand and gravel with a thickness of not less than 200 mm. The concrete anti-seepage layer can be made of anti-seepage steel fiber concrete, anti-seepage synthetic fiber concrete, anti-seepage reinforced concrete, and anti-seepage plain concrete ； The concrete impermeable layer shall be provided with contraction joints and expansion joints. The form, spacing, width, depth of these joints, as well as the sealing materials and backing materials used for filling the joints, shall comply with the relevant provisions in paragraphs 5.2.5 to 5.2.7 of this standard. In addition, paragraph 5.2.8 specifies the width, depth, sealing materials, and backing materials for the joints that should be provided at the intersections of walls, columns, and foundations in the concrete impermeable layer ； Paragraph 5.2.9 specifies that sealants for joints should be weather-resistant materials such as silicone sealants used in road construction; joint filler boards should be made of closed-cell polyethylene foam plastic or fiberboard, while the backing material should be closed-cell expanded polyethylene, polyvinyl chloride, or elastic polypropylene foam rods. The diameter of these foam rods should be no less than 1.25 times the width of the joint. The thickness of the high-density polyethylene (HDPE) membrane barrier layer should not be less than 1.5 mm, and its burial depth should not be less than 300 mm ； Protective layers should be installed above and below the membrane; these protective layers can be made of filament non-woven geotextiles. A sand layer free of sharp particles can also be used as the protective layer beneath the membrane, with a thickness of not less than 100 mm ； A layer of sand and gravel should be placed above the protective layer on the membrane, with a thickness of not less than 200 mm ； The HDPE membrane should be sloped toward blind ditches or drainage ditches. The drainage material used in these ditches should be materials with good permeability, such as gravel or crushed stones covered with long-fiber non-woven geotextiles; alternatively, perforated HDPE drainage pipes also covered with long-fiber non-woven geotextiles can be used. For the waterproof layer made of sodium-based bentonite membranes, it is advisable to use those produced by the needle-punching and coating method. From bottom to top, the structure consists of the foundation, the sodium-based bentonite membrane, a sand and gravel layer, and a concrete layer. The thickness of the sand and gravel layer should not be less than 300 mm; the strength grade of the concrete layer should be at least C20, with a thickness of 100 mm. 5.6 Tank accessories: Vertical storage tanks should be equipped with ladders, platforms, and railings at the top. For vertical storage tanks with a height of more than 5 meters, spiral ladders should be used ； Anti-slip steps and guardrails should be installed in areas on the tank roof that are frequently walked on ； A measurement platform should be provided at the measurement hole ； Fixed-roof storage tanks and above-ground horizontal tanks used for storing Class B and Class II liquids shall be equipped with breather valves. The exhaust pressure of the breather valves must be lower than the design positive pressure of the tanks, while the intake pressure must be higher than the design negative pressure. When the ambient temperature where the breather valves are installed may be equal to or lower than 0°C, all-weather breather valves should be selected ； Flame arresters must be installed on the vent pipes of fixed-roof storage tanks and above-ground horizontal storage tanks used for storing Class A and B liquids ； Spraying method shall not be used for filling the storage tank ； Storage tanks that require dehydration operations should be equipped with automatic dehydrators. Article 7.1.7 of the “Construction Standards for Petroleum Product Storage Tanks” stipulates that bottom samplers should be installed on oil tanks. Article 8.5 stipulates that the drain pipe at the bottom of the oil tank shall be equipped with a double valve ； The oil level gauging port of the tank should be installed separately; on both sides of the gauging port, a set of grounding terminals should be provided for grounding sampling tools ； Internal floating roof oil tanks should be equipped with an in-tank oil inlet diffuser pipe ； Internal floating roof oil tanks shall be provided with circumferential vent holes at the edge of the tank roof. 5.7 Fire dike 5.7.1 Requirements for fire dike installation: A fire dike shall be installed around above-ground tank groups, and the effective capacity of this fire dike shall not be less than the capacity of the largest tank within the tank group ； The distance from the tank wall of an above-ground vertical storage tank to the inner footline of the fire dike should not be less than half of the tank wall height ； The actual height of the fire dike surrounding the above-ground tank farm should be 0.2m higher than the calculated height. The height of the fire dike above the designed floor level inside the dike should be no less than 1.0m, while it should not exceed 3.2m above the designed floor level outside the dike or the surface of the fire truck access road (whichever is lower) ； The fire resistance rating of the fire dike should not be less than 5.5 hours ； The areas where pipes pass through fire dikes should be tightly filled with non-combustible materials; drainage control measures should be implemented at the points where rainwater drains (pipes) pass through fire dikes ； In each compartment of the fire dike, steps or ramps should be provided for pedestrians to access it, and the distance between adjacent steps or ramps should not exceed 60 meters ； The dike should be a solid wall constructed from non-combustible materials, with a height of 0.5 to 0.8 meters being appropriate. Article 3.1.2 of the \"Code for Design of Fire Dams in Tank Farm Areas\" (GB 50351-2014) stipulates that fire dams shall be constructed from non-combustible materials, and must be tight, airtight, and leak-proof. Section 3.1.4 stipulates that all types of pipelines and cables entering or leaving the tank farm should cross above the top of the fire dike or pass beneath the ground. When it is necessary to pass through the fire dike, sleeves should be installed and sealed tightly with non-combustible materials, or fixed short pipes should be used with both ends sealed using flexible hoses. Article 3.1.5 stipulates that drainage ditches should be installed in the area within the fire dike; these ditches must have leak-proof measures, and grid covers should be installed on them. The material of such grid covers should possess fire-resistant and corrosion-resistant properties. Article 3.1.7 stipulates that each storage tank group shall be equipped with no fewer than 2 pedestrian steps or ramps leading over the dike, which shall be located in different directions. Article 3.1.8 stipulates that guardrails shall be provided on steps or ramps with a height of 1.2 m or more. Article 3.2.8 stipulates that the ground within the fire dike shall slope toward the drainage ditches and outlets, with a slope of preferably 0.5% ； When oil tank leaks may contaminate groundwater or the surrounding environment, leak-proof measures should be taken for the ground inside the dike. Article 3.2.9 stipulates that water collection facilities shall be installed within the fire dike; the rainwater drainage pipes connected to these facilities shall extend outside the dike below the designed ground level inside the dike, and safe and reliable measures shall be taken to prevent oil from entering the drainage system. Section 4.2.8 stipulates that the top of brick or block fire dikes shall be provided with a cast-in-place reinforced concrete cap, which shall be disconnected at deformation joints. Article 6.2.17 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that the fire dike around vertical storage tanks should not be higher than 2.2 m (based on the design floor level within 3 m outside the dike). **The Notice of the State Administration of Work Safety on Further Strengthening the Safety Management of Chemical Storage Areas (An Jian Zong Guan San [2014] No. 68) stipulates that fire dikes or fire barriers should be installed for combustible liquid storage tanks in accordance with the requirement of one dike per tank. 5.7.2 Seepage prevention requirements for fire dikes: Clause 5.3.6 of the \"Technical Specifications for Seepage Prevention in Petrochemical Projects\" (GB/T 50934) stipulates that fire dikes should be constructed using reinforced concrete with good seepage resistance, and the seepage resistance grade should not be lower than P6 ； Water-stop strips made of stainless steel should be installed at the deformation joints of fire dikes, with a thickness of not less than 2.0 mm ； A gasket plate, backing material, and sealing gasket material should be installed in the deformation joint of the fire dike. 6. For pump stations handling flammable and combustible liquids, above-ground designs are preferred. The headroom in the pump house or pump shed should meet the requirements for equipment installation, maintenance, and operation, and should not be less than 3.5 m ； The doors of the pump room should open outward, and there should be no fewer than 2 such doors; one of them should be large enough to accommodate the entry and exit of the largest equipment in the pump room. If the floor area is less than 100 m2, only one outward-facing door is required ； The lighting area provided by the doors and windows of the pump room (space) should not be less than 15% of its floor area ； The equipment platform of the pump house or open-air pumping station should be at least 0.15 m higher than the surrounding ground level. When it is necessary to change the diameter of the horizontal inlet pipe of a centrifugal pump, an eccentric reducer should be used; such a reducer should be installed near the pump inlet. When the liquid in the pump’s inlet pipe flows from top to bottom into the pump, it should be installed with its bottom at the same level ； A filter should be installed on the inlet pipeline of the pump; a magnetic composite filter should be used for the inlet pipeline of magnetic pumps. The filter shall be installed in the section of the pipeline between the valve on the pump’s inlet pipeline and the pump’s inlet flange. A check valve should be installed on the pump’s outlet pipe; it should be placed in the section of the pipe between the valve on the outlet pipe and the pump’s outlet flange ； A high-point vent valve should be installed on the pipeline between the pump’s inlet and outlet. The discharge outlet must be located outside the pump room (shed), at a height of 4 meters or more above the surrounding ground level; if it is placed above the roof of the pump room (shed), it should be at a height of 1.5 meters or more above that roof. The horizontal distance between the discharge outlet and any openings such as doors and windows in the pump room should be at least 3.5 meters, while the horizontal distance from it to doors, windows in the electrical distribution room, and any non-explosion-proof electrical equipment should be at least 5 meters ； A flame arrester should be installed at the exhaust pipe outlet. When there is no centralized pumping station in the loading and unloading area for flammable and combustible liquids, the pumps can be installed beneath the railway tank car loading and unloading trestles or the road tank car loading and unloading platforms; however, natural ventilation conditions must be ensured, and the top surface of the pump foundation should be above the surrounding ground level as well as above the highest possible water level. Article 8.8.4 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that in enclosed pump rooms for Class A and B equipment with an indoor volume of less than 500 m3, fixed fire-suppression steam perforated pipes shall be installed along one side wall at a height of 150–200 mm above the ground; semi-fixed fire-suppression steam pipe connections shall be installed appropriately along the other side wall. The valves for the fixed perforated pipes or semi-fixed connections shall be installed in locations that are visible, safe, and easy to access. Section 8.8.2 stipulates that the fire extinguishing steam pipe shall be led out above the main pipe, and the steam pressure should not exceed 1 MPa. 7. Facilities for loading and unloading flammable and combustible liquids: Article 7.4 of the \"Construction Standards for Finished Oil Depots\" stipulates that finished oil depots shall be equipped with a sealed loading and unloading system for oils; the maximum allowable leakage rate of oil and gas from such a sealed system is ≤10 g/m3. 7.1 Railway tank car loading and unloading facilities: The railway loading and unloading lines should be straight and end-ended ； When filling armored Class B and Class C liquids into railway tank cars from above, a dip pipe inserted into the bottom of the tank car should be used. The flow rate of the liquid inside the dip pipe should not exceed 1 m/s before it is submerged in the liquid, and should not exceed 4.51 m/s after it is submerged ； Tank truck loading and unloading trestles should not be installed on both sides of the same loading and unloading line at the same time ； The deck of the tank truck loading/unloading quay should be 3.5 m above the rail level. Safety railings should be installed on the quay, and ladders for ascending and descending the quay should be provided at both ends of it as well as every 60 m to 80 m along its length ； When the distance between the edge of the bridge deck on the tank truck loading/unloading line and the centerline of that line is 3 m or less above the rail surface, it should be no less than 2 m; when it is more than 3 m above the rail surface, it should be no less than 1.85 m ； While ensuring the quality of the liquids being loaded and unloaded, liquids with similar properties can share the same loading arm; however, loading arms for aviation fuels must be used exclusively for such purposes ； Filling railway tank cars with Class B and Class C liquids should be carried out in a sealed manner, and oil and gas recovery facilities should be installed. Article 4.4.4 of the Code for Fire Protection Design of Petrochemical Enterprises (GB50160-2008) stipulates that in railway loading and unloading areas for Class A and B liquids, the distance between internal combustion locomotives and the crane pipes at another stack should not be less than 12 m. Section 4.4.5 stipulates that when the railway loading and unloading line for flammable liquids is a dead-end line, the distance from the stop device to the last car position shall not be less than 20 m. Section 6.4.1 stipulates that for Class A and B liquids loaded through an open top, submersible loading nozzles shall be used; an easily operable emergency shut-off valve shall be installed on the combustible liquid inlet pipeline at a distance of more than 10 m from the edge of the loading platform, and the distance between the zero-level tank and the tank truck loading/unloading line shall be no less than 6 m. 7.2 The loading and unloading of liquid substances of Class A and B into road tankers should be carried out within a loading shed; road tankers carrying liquids of Class A/B and Class C can share the same loading shed ； The filling shed shall be a single-story pass-through structure; the clear height from the canopy to the ground must meet the requirements for tank truck filling operations and shall not be less than 5.0 m. The width of the filling passage must meet the requirements for filling operations, and its floor level shall be higher than that of the surrounding area. When there is a height difference in the terrain that can be utilized, it is advisable to use a method of direct gravity-fed loading into the tanks, to employ a quantitative loading control system, and to use bottom-loading ； When filling tank cars with Class A or B liquids using a loading dipstick, a dipstick that can reach the bottom of the tank car should be used. The flow rate of the liquid inside the dipstick should not exceed 1 m/s before the tip of the dipstick is submerged in the liquid, and should not exceed 4.5 m/s after it is submerged ； A sealed loading method should be adopted, and oil and gas recovery facilities should be installed. Article 6.4.2 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that the entrances and exits of loading and unloading stations should be located separately; when the entrance and exit are shared, a turnaround area shall be provided within the station ； The loading and unloading yard should have a floor made of cast-in-place concrete ； For the loading and unloading of Class A B and Class B liquids, submersible loading nozzles should be used ； The distance between the crane positions for loading and unloading should not be less than 4m. 8. Process and thermal pipelines 8.1 Pipelines within the warehouse 8.1.1 Pipelines shall be installed above ground; process and thermal pipelines in oil warehouses should preferably be installed above ground or in open trench systems ； As required, it can be laid underground in certain areas or installed using sand-filled sealed trenching ； Above-ground pipelines should not be arranged around the tank farm, nor should they obstruct the passage of fire trucks ； Pipes installed between the fire dike and the fire access road should not impede the passage and operations of firefighters. Article 7.1.5 of the \"Construction Standards for Finished Oil Storage Tanks\" stipulates that for the pressure relief interfaces of oil pipelines, in the case of internal floating roof tanks, an intersecting-shaped pipe can be installed along the tank wall before connecting to the tank’s inlet and outlet pipes; for dome-shaped tanks, the connection can be made from the top of the tank down to its lower part, allowing the oil to flow slowly along the tank wall into the tank without causing any dripping or spraying. Article 7.3 stipulates that process pipelines within the tank should preferably be laid on ground-level pipe supports; the main pipeline should slope at a rate of 3% toward the pump set. Measures such as venting, draining, and safety pressure relief should be implemented for the process pipelines. Vent and drain openings that are not used frequently should be sealed with flange covers ； Steel grating is recommended for the valve operation platforms and ladder steps on process pipelines ； The protective railing on the valve operation platform should be installed on one side of the platform ； Automatic pipeline pressure monitoring instruments should be installed on the main process pipelines to transmit pressure signals to the central control room, enabling alarms to be triggered when pressure levels exceed acceptable limits. 8.1.2 When pipes pass under railways and roads, the angle of intersection should be no less than 60°; the sections of pipes that pass underneath such structures should be placed within culverts or sleeves, or other protective measures should be taken ； Pipeline bridges and culverts should be filled and compacted with sand (soil) ； The end of the sleeve should extend at least 0.6 m beyond the foot of the slope or the subgrade; when passing through a drainage ditch, it should extend at least 0.9 m beyond the edge of the ditch ； The top of the casing shall be no less than 0.8 m below the railway track surface, and no less than 0.6 m below the road surface ； The casing shall meet the pressure resistance requirements. 8.1.3 When pipes are laid underground, if surface pipes are arranged parallel to a road, the distance from them to the roadside should be no less than 1 m; when underground pipes are arranged parallel to a road, they must not be laid beneath the road surface. The burial depth should be below the maximum depth of permafrost; when buried in the permafrost layer, frost expansion prevention measures must be in place ； The distance from the top of the pipe to the ground should not be less than 0.5m ； In areas with concrete floors, whether indoors or outdoors, the depth of the pipe crown below the concrete structure layer should be no less than 0.3 m ； Buried pipelines transporting flammable and combustible media should not pass through cable trenches; if this is unavoidable, protective sleeves should be installed ； When the temperature of the liquid in the pipeline exceeds 60°C, insulation material should be filled inside the casing to ensure that the temperature of its outer wall does not exceed 60°C℃ ； Buried pipelines shall not be laid parallel and overlapping ； Buried pipelines should not be installed within the range of pressure influence from the foundations of adjacent buildings (structures), and their construction and maintenance excavations should avoid compromising the stability of the foundations of nearby equipment and buildings (structures). When heat pipelines laid underground run parallel to Class A and Class B process pipelines also laid underground, the clear distance between them should be no less than 1 m. When they intersect with such Class A and Class B process pipelines, the clear distance between them should be no less than 0.25 m; moreover, the process pipelines should preferably be located below other pipelines and trenches. 8.1.4 Pipelines shall be laid in trenches; thermal pipelines must not be laid in the same trench as pipelines for Class A and Class B liquids ； When pipes are laid in trenches, a sealed partition wall should be installed at the junction of the trench with the pump house and the fire dike of the tank bank. When pipes are laid in trenches that are sealed with sand or without sand, thermal pipelines and process pipelines for heated transportation shall not be laid in the same trench as those used for transporting liquids of categories A and B ； The piping layout within the trench should facilitate maintenance and replacement of piping components ； The clear height of unlined trench closures should not be less than 1.8 m, and the clear width of the maintenance passage within the trench should not be less than 0.7 m ； Non-sand-filled enclosed trenches should be equipped with safe entrances and exits, and manholes or ventilation openings suitable for personnel entry and exit should be provided every 100 meters. 8.1.5 Welding connections shall be used between pipeline connections, accessories, and protective pipes, as well as between pipelines and fittings ； Flange connections are preferred between pipes and equipment, as well as between valves and instruments; when threaded connections are used, it is necessary to ensure the strength and tightness of the connection ； Pipelines connected to equipment such as storage tanks should have sufficient flexibility, and must meet the allowable stress requirements for the equipment’s connections ； Valves on process pipelines should be made of steel; electric or pneumatic valves selected should have a manual operation function ； For valves with a nominal diameter of 600 mm or less, the time required to manually close the valve should not exceed 15 minutes ； For valves with a nominal diameter greater than 600 mm, the time required to manually close the valve should not exceed 20 minutes. The outer surfaces of steel pipes and their accessories shall be coated with an anti-corrosion coating; buried steel pipes shall also receive anti-corrosion, insulating, or other protective measures ； For process pipelines in which the liquid pressure inside the pipeline may exceed its design pressure, pressure relief devices should be installed at appropriate locations ； Pipelines transporting easily coagulating liquids or liquids prone to self-polymerization shall adopt measures for removing coagulates or preventing self-polymerization respectively. Article 6.2.25 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that the inlet and outlet pipelines of storage tanks shall use flexible connections. Paragraph 7.2.1 stipulates that when metal pipes and valves for flammable liquids with a nominal diameter of 25 mm or less are connected using tapered threads, seal welding shall be performed at the threads. 8.2 Pipelines outside the warehouse: When pipelines outside the warehouse are laid underground, prominent permanent markers shall be placed on the ground ； When overhead pipelines outside the tank pass through densely populated areas, protective fences should be installed to prevent people from entering ； Process pipelines buried outside the tank should not intersect with or be arranged adjacent to municipal pipelines or hidden ditches (canals) ； Isolation valves should be installed at convenient locations on the pipelines outside the tank area and the off-site loading/unloading area for easy operation. Article 7.2.9 of the Code for Fire Protection Design of Petrochemical Enterprises (GB50160-2008) stipulates that Class A and Class BA pipelines shall be equipped with inert gas displacement facilities. 9. Fire protection facilities
9.1 Fire foam systems
9.1.1 Foam fire extinguishing systems
Above-ground fixed-roof tanks, internal floating-roof tanks, and above-ground horizontal tanks shall be equipped with low-expansion or medium-expansion foam fire extinguishing systems ； External floating roof storage tanks should be equipped with a low-expansion foam fire extinguishing system. 9.1.2 Installation of foam fire extinguishing systems: Fixed foam fire extinguishing systems shall be used for above-ground vertical storage tanks holding water-soluble liquids with a capacity of more than 500 m3, as well as for above-ground vertical storage tanks holding other flammable and combustible liquids of Class A B and Class B with a capacity of more than 1000 m3 ； Semi-fixed foam fire extinguishing systems can be used for above-ground vertical storage tanks holding water-soluble liquids with a capacity of 500 m3 or less, and for above-ground vertical storage tanks holding other flammable or combustible liquids with a capacity of 1000 m3 or less ； Mobile foam fire extinguishing systems can be used for above-ground horizontal storage tanks and above-ground storage tanks with a capacity of not more than 200 m3. When a fixed foam fire extinguishing system is used in the storage tank, mobile foam fire extinguishing equipment such as foam hoses, foam nozzles, and fire hoses should also be provided ； The foam liquid reserve should include a surplus of not less than 100% based on the calculated amount. 9.1.3 The foam mixing unit should adopt processes such as balanced ratio foam mixing or pressure ratio foam mixing. Article 3.1.2 of the \"Code for Design of Foam Fire Extinguishing Systems\" (GB 50151-2010) stipulates that foam mixture pumps, foam liquid pumps, foam liquid storage tanks, foam generators, foam liquid pipelines, foam mixture pipelines, foam pipelines, and pipeline filters should be painted red ； Foam fire pumps and water supply pipes should be painted green. Section 3.2.3 stipulates that for water-soluble Class A and Class B liquids, solvent-resistant foam agents must be used. Section 3.4.5 stipulates that for environmentally friendly proportional mixers, the liquid intake port shall not be more than 1 m above the lowest liquid level in the foam liquid tank, and there shall be at least one spare unit available. Section 3.5.2 stipulates that the foam liquid tank shall be equipped with a discharge port, a level gauge, a feed hole, a slag discharge hole, an access hatch, a sampling port, and a vent valve or air exhaust pipe. The storage tank shall have markings indicating the type and model of the foam liquid, as well as the date of manufacture and filling and the storage capacity. Section 3.6.1 stipulates that for low-pressure foam generators, vertical foam generators should be used in fixed-roof storage tanks; the outlet of horizontal foam generators shall be equipped with a foam pipe with a length of not less than 1 m. Foam generators installed on external floating-roof storage tanks shall not have sealed glass. Section 3.7.1 stipulates that the control valves used in foam fire extinguishing systems shall have distinct open and closed indicators. Section 3.7.2 stipulates that manual valves should not be used when the diameter of the outlet pipe of the foam mixture pump is greater than 300 mm. Section 3.7.6 stipulates that foam liquid pipelines shall be made of stainless steel pipes. Section 3.7.10 stipulates that dry pipes installed above ground or in trenches within explosion-proof areas shall be equipped with anti-static grounding measures. Section 4.1.3 stipulates that the designed amount of foam mixture required by the foam fire extinguishing system in the tank area to extinguish a single fire shall be determined based on the maximum value of the sum of the amount needed inside the tank, the amount required by the auxiliary foam nozzle associated with that tank, and the remaining amount in the pipelines. Article 4.1.4 stipulates that storage tank areas equipped with fixed foam fire extinguishing systems shall be provided with auxiliary foam nozzles for extinguishing liquid spill fires. The number of such nozzles and the continuous supply time of the foam mixture shall meet the requirements specified in Table 8; the flow rate of the foam mixture from each auxiliary foam nozzle shall be no less than 240 L/min. Table 8: Number of foam guns and continuous supply time of foam mixture. Tank diameter (m), Number of foam guns installed, Continuous supply time (min): ≤10: 1, 10; >10 and ≤20: 1, 20; >20 and ≤30: 2, 20; >30 and ≤40: 2, 30; >40: 3, 30. Article 4.1.6 stipulates that a location for installing a foam mixture flow detector should be reserved on the main pipe of the foam mixture in fixed foam fire extinguishing systems ； A test and inspection port should be installed on the main pipeline of the foam mixture ； Pressure gauge connections for monitoring the operating pressure of the foam generator should be provided on the pipes at the most unfavorable and most favorable hydraulic conditions outside the fire dike. Section 4.1.9 stipulates that the fixed foam fire extinguishing system in the tank farm shall have the functions of a semi-fixed system. Section 4.1.10 stipulates that the design of fixed foam fire extinguishing systems shall ensure that, after the foam mixture pump is started, the foam mixture is delivered to the area to be protected within no more than 5 minutes. Section 4.2.6 stipulates that each foam generator shall be connected to a separate mixture pipeline leading outside the fire dike ； The foam mixture riser connecting to the foam generator should be fixed to the tank wall using pipe clamps, with the spacing between these clamps not exceeding 3 meters ； A rust residue cleaning port should be provided at the lower end of the riser for the foam mixture. Section 4.2.7 stipulates that the above-ground foam mixture pipes or foam horizontal pipes within the fire dike should be installed on pipe supports or pipe racks, and they should be connected to the foam mixture vertical pipes on the tank wall using flexible metal hoses ； The foam mixture pipes inside the fire dike should have a drainage slope of 3‰. Section 4.2.8 stipulates that for fixed above-surface spraying systems, an independent control valve shall be provided outside the fire dike for each foam generator ； For semi-fixed above-surface spraying systems, for each foam generator, a pipe thread connection with a plug should be installed at a height of 0.7 m above the ground outside the fire dike ； A vent valve should be installed on the foam mixture pipeline, and the pipeline should have a slope of 2‰ leading toward the vent valve. Section 8.1.5 stipulates that a water level indicator device shall be installed in the foam fire pump station. Article 4.2.8 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB 50160-2008) stipulates that foam stations in tank areas should be located in non-explosion-proof areas outside the fire dikes surrounding the tank groups, and the fire separation distance from flammable liquid tanks should not be less than 20 meters. 9.2 Fire water system 9.2.1 Fixed fire cooling water systems shall be installed for above-ground vertical storage tanks with a capacity of 3000 m3 or more, or whose tank wall height is 15 m or more ； For aboveground vertical storage tanks with a capacity of less than 3,000 m³ and a shell height of less than 15 m, as well as other storage tanks, a mobile fire cooling water system may be installed. 9.2.2 Installation of fire valves – Fire valves that need to be operated in case of a fire should not be located within fire dikes ； The distance between the fire valve and the wall of the tank involved in the fire should not be less than 15 m; this requirement does not apply if there are reliable protective measures to allow easy access to the fire valve. 9.2.3 Fire water supply: Primary oil depots shall be equipped with an independent fire water supply system ； When a oil depot uses a low-pressure fire water supply system, it shall be ensured that at each fire hydrant outlet, the water supply pressure shall not be less than 0.15 MPa when the designed fire water volume is reached ； The fire water supply system should be kept filled with water ； The fire supply pipes in the above-ground tank area of a Class I petroleum depot should be laid in a circular pattern; there should be no fewer than 2 inlet pipes, and each pipe should be capable of handling the total amount of fire-fighting water required. The fire water demand shall be the sum of the foam water required to extinguish a fire in the tank with the highest fire protection requirements, and the maximum water amount needed to cool the tanks. Article 8.5.1 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that storage areas in large petrochemical enterprises shall be equipped with an independent fire protection water supply system with a stable high pressure, preferably ranging from 0.7 to 1.2 MPa. Article 8.5.2 stipulates that circular pipelines shall be divided into several separate sections using valves, and the number of fire hydrants in each section should not exceed 5 ； In the event of an accident in a certain section of the loop, the remaining sections of the independent fire water supply pipeline should be able to meet 100% of the fire water demand. Section 8.5.3 stipulates that fire supply pipes shall be kept filled with water. Underground fire supply pipes that are independent from other systems shall be buried below the freezing line, with the top of the pipe being at least 150 mm above the freezing line. Section 8.5.4 stipulates that the flow velocity in an independent fire water supply pipe should not exceed 3.5 m/s. Article 5.2.5 of the \"Technical Code for Water Sprinkler Fire Extinguishing Systems\" (GB 50219-2014) stipulates that fire pump systems shall be equipped with a test pump return pipe and an overpressure return pipe; where conditions permit, these two pipes may share the same return pipe. 9.2.4 Scope of fire-fighting cooling water supply: Fixed-roof storage tanks located at the site of the fire, as well as adjacent above-ground storage tanks within a distance of 1.5D from the wall of such storage tanks, shall all be cooled ； On fire floating-roof and internal-floating-roof storage tanks should be cooled, while adjacent tanks need not be cooled; however, if the floating disk of the on fire internal-floating-roof storage tank is made of a fusible material, the adjacent tanks should also be cooled. Article 3.2.6 of the \"Technical Code for Water Spray Fire Extinguishing Systems\" (GB 50219-2014) stipulates that when the protected objects are storage tanks containing Class A or Class B liquids, the distance between the water spray nozzles and the outer wall of the storage tanks shall not exceed 0.7 m. 9.2.5 When the fire cooling water pipes are installed beneath a storage tank’s wind-resistant ring or reinforcement ring, which does not have the function of guiding cooling water, a cooling spray ring should be installed below them ； Water curtain nozzles should be installed on the cooling spray ring pipe; the spacing between these nozzles should not exceed 2 meters, and the water output pressure from the nozzles should be no less than 0.1 MPa ； A cleaning port should be provided at the lower end of the inlet pipe for the cooling water of the storage tank, and the lower end of this cleaning port should be at least 0.3 m above the top surface of the tank foundation ； Control valves and drain valves should be installed on the fire cooling water pipes. If the fire cooling water is sourced from surface water, filters should be installed on these pipes as well. Article 8.6.7 of the “Code for Fire Protection Design of Petrochemical Enterprises” (GB50160-2008) stipulates that anti-freezing measures shall be taken for fire-fighting facilities such as fire hose reels, fire monitors, water spray systems, or water mist systems installed in cold regions. Article 3.2.12 of the \"Technical Code for Water Sprinkler Fire Extinguishing Systems\" (GB 50219-2014) stipulates that the cooling water annular coil for fixed-roof storage tanks and internal floating-roof storage tanks treated as such should be arranged in a single loop along the top of the tank wall ； When the cooling water loop on the storage tank is divided into two or more arc-shaped sections, these sections shall not be connected to each other; instead, they shall be connected to water supply pipes located outside the fire dike. Control valves that can indicate whether they are open or closed shall be installed on these inlet pipes outside the fire dike ； The cooling water standpipes should be fixed to the tank wall using pipe clamps, with a spacing of no more than 3 meters between them. A cleaning outlet for rust debris should be provided at the lower end of each standpipe; this outlet should be located at a distance of more than 300 mm above the top surface of the tank foundation, and the length of the pipe section used to collect rust debris should be no less than 300 mm. Section 3.2.13 stipulates that for systems used to protect storage tanks for Class A B and Class B liquids, the connection between the vertical pipes and the horizontal pipes within the tank bank shall be capable of eliminating the stresses caused by the settlement of the tanks. Section 4.0.4 stipulates that when the system’s water supply control valve is an electric control valve, it should be able to indicate whether the valve is open or closed; it must have the capability to receive control signals in order to open or close the valve. The time required for the valve to open should not exceed 45 seconds. The system should be able to issue an alarm in case of a valve failure and display the cause of the failure. It should also have a function for emergency mechanical operation on-site. When the valve is installed in a valve chamber, it is advisable to lengthen the valve stem and to position the electric actuator above the cover of the chamber. Section 4.0.6 stipulates that a drain valve or sewage outlet should be installed at the lowest point of the pipeline. 9.2.6 Minimum supply time for fire cooling water: For above-ground fixed-roof storage tanks with a diameter greater than 20 m, and for above-ground floating-roof storage tanks with a diameter greater than 20 m that have floating roofs made of fusible materials, this time should be no less than 9 hours; for other above-ground vertical storage tanks, it should be no less than 6 hours ； The loading and unloading facilities for railway tank cars and road tank trucks should be no less than 2 hours. 9.2.7 The number of fire hydrants in a mobile fire cooling water system for fire hydrants shall be determined based on the amount of fire-fighting water required for cooling and extinguishing the storage tanks, as well as the protection radius of each fire hydrant ； The protection radius of a fire hydrant should not exceed 120 m, and fire hydrants located within 15 m of the wall of the tank on fire should not be taken into account ； The distance between fire hydrants in the fixed fire cooling water system for storage tanks should not exceed 60 m. Article 8.5.2 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that circular pipelines should be divided into several separate sections using valves, and the number of fire hydrants in each section should not exceed 5. Article 8.5.5 stipulates that above-ground fire hydrants should be preferred, and these hydrants ought to be installed along roads ； The fire hydrant should not be more than 5 m away from the edge of the road, and it should not be less than 5 m away from the exterior wall of buildings ； The large-diameter outlet of above-ground fire hydrants should face the road. When the installation site is susceptible to vehicle collisions, protective measures should be put in place around them. 9.3 Fire pumps: The fire cooling pumps and foam fire pumps in Class I oil depots shall be equipped with at least one spare pump each ； When the fire pump for a Class I oil depot is powered by two independent power sources, the main pump should be an electric pump, while the backup pump can be either an electric pump or a diesel engine pump ； When the fire pump is powered by only one power source, the specifications (flow rate, head) and quantity of the standby diesel pumps should not be lower than those of the main electric pump ； Fire pump systems should be capable of starting under positive pressure or by self-priming. When the suction pipes of multiple fire pump units share one main pipe before the pumps, this pipe shall be connected to the fire water tank via two branch pipes, and each branch pipe shall be capable of handling the total water demand. Article 8.3.5 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that when two or more fire pump units are arranged together, there should be no less than two suction pipes; when one of these pipes is under maintenance, the remaining suction pipes must be capable of supplying all the required fire-fighting water volume ； For pump groups, there must be at least two discharge pipes connected to the looped fire protection water piping. Valves shall be installed between the two connection points. When one discharge pipe is under maintenance, the remaining discharge pipes must be capable of delivering the total required fire-fighting water flow ； The discharge pipe of the pump shall be equipped with safety devices to prevent overpressure ； For outlet pipes with a diameter greater than 300 mm, manual valves should not be used; the opening and closing of the valves must be clearly indicated. Section 8.3.6 stipulates that separate standby pumps shall be provided for fire pump and pressure stabilization pumps. Section 8.3.7 stipulates that fire pumps shall be brought into operation within 2 minutes upon receiving an alarm, and the fire pumps in a constant-high-pressure fire water supply system shall be able to start automatically based on the pressure drop signal in the pipeline network. Section 8.3.8 stipulates that fire pump systems shall be equipped with dual power sources; when diesel engines are used as the power source, the fuel reserve of these engines must be sufficient to enable the unit to operate continuously for 6 hours. 9.4 Fire water tank: The time required to refill the fire water tank should not exceed 96 hours, and the tank must be equipped with a water intake for fire trucks to draw water from. Article 8.3.2 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that the water replenishment time for pools should not exceed 48 hours. In cold regions, anti-freezing measures shall be adopted for pools, and fire protection pools should be equipped with liquid level monitoring systems, alarms for high and low liquid levels, as well as automatic water replenishment facilities. 9.5 For fire extinguishing equipment in storage tank groups, one 8 kg portable dry powder fire extinguisher should be provided for every 400 m2 of area within the fire dike; if the calculated number exceeds 6, then 6 extinguishers shall be installed ； Every 12 meters along the railway loading platform, 2 8 kg dry powder fire extinguishers should be installed ； Each road loading station should be equipped with 2 8kg dry powder fire extinguishers ； The quantity of fire blankets and fire sand available in the key areas of oil depots should not be less than those specified in Table 9: Table 9 – Quantity of Fire Blankets and Fire Sand Required in Key Areas of Oil Depots. Area | Fire Blankets (pieces) | Fire Sand (m3) | Tank Farm | 4–6 | 2 | Pump House | — | 2 | Railway Wharf | 4–6 | — | Road Dock | 4–6 | 1 | Fire Pump House | 2 | Power Distribution Room | 2 | Pipeline Bridges and Culverts | 2 | Points where Rainwater Ditches Meet the Main Ditch | 2. Article 8.9.1 of the Code for Fire Protection Design of Petrochemical Enterprises (GB50160-2008) stipulates that dry powder or foam fire extinguishers should be installed in production areas, while gas-type fire extinguishers are suitable for control rooms, cabinet rooms, computer rooms, telecommunications stations, laboratories, etc. Article 8.9.4 stipulates that at railway loading and unloading platforms for flammable liquids, 2 portable dry powder fire extinguishers shall be installed at each level, every 12 meters along the platform. 9.6 Fire Control Room: A fire control room shall be installed within the oil depot, and a dedicated telephone for recording alarm calls shall be provided in this room ； The fire control room of a Class I oil depot should be located together with the control room of the fire pumps ； Direct telephone lines should be established between the fire control room, the oil depot dispatch room, and the urban fire stations ； The alarm signals from oil depots with a total tank capacity of 50,000 cubic meters or more should be displayed in the fire control room ； Fire alarm phones should be installed in the control rooms of the tank storage area, loading/unloading area, and auxiliary operation area ； In the tank storage areas and loading/unloading areas, outdoor manual alarm installations should be installed along the roads surrounding them, with a spacing of no more than 100 meters between such installations ； When fiber-optic temperature sensors are used, the sensors should be installed above the secondary sealing ring of the storage tank’s floating deck, and the spacing between the grating sensors should not exceed 3 meters. Article 8.12.1 of the Code for Fire Protection Design of Petrochemical Enterprises (GB50160-2008) stipulates that automatic fire alarm systems and fire telephone alarm systems shall be installed in areas prone to fire in the production areas of petrochemical enterprises, as well as in their utility and auxiliary production facilities, plant-wide critical facilities, and regionally important facilities. Section 8.12.2 stipulates that fire stations shall be equipped with answering telephones capable of receiving alarms from no less than 2 fire incidents simultaneously, as well as wireless communication equipment. Article 8.12.3 stipulates that the automatic fire alarm system shall be equipped with an alarm device; if there is a public address system in the production area, it can also serve as an alarm device ； When there is no amplified intercom system in the production area, an audio-visual alarm should be installed ； The fire alarm controller should be installed in a location where there is 24/7 staffing, and all of its information should be transmitted to the central control room via the network ； The automatic fire alarm system can receive alarm signals from the video surveillance system; video surveillance systems should also be installed at important fire alarm locations ； Fire emergency broadcasting systems should be installed in important fire-hazardous areas. Paragraph 8.12.4 stipulates that manual fire alarm buttons shall be installed along the roads surrounding Tank Farms Category A and B, with a spacing of no more than 100 meters between them. Article 8.12.5 stipulates that an automatic fire alarm system should be installed at the sealing ring of floating roof tanks with a single-tank volume of 10,000 cubic meters or more and less than 30,000 cubic meters. Paragraph 8.12.6 stipulates that: For the automatic fire alarm system, power supply via an uninterruptible power supply (UPS) shall be given priority; the DC backup power source shall utilize a dedicated battery for the fire alarm controller. It is necessary to ensure that the continuous power supply duration is no less than 8 hours in the event of a main power failure. 10. Water supply, drainage, and wastewater treatment 10.1 Oil-containing and oil-free wastewater from oil depots should be discharged using a separate drainage system ； Uncontaminated surface rainwater and production wastewater may be discharged through open ditches; it is advisable to locate the discharge outlets collectively at the perimeter fence of the oil depot ； When oil-containing wastewater pipes within the fire dike of the storage tank area emerge outside the dike, measures should be taken outside the dike to prevent leaks of flammable and combustible liquids from escaping into the tank area ； Water seal wells shall be installed at the fire dikes surrounding the tank farm, at the drainage pipe outlets of other buildings/structures, at the junctions of branch pipes and main pipes, and every 300 meters along the main pipes for oil-containing wastewater pipelines ； For the drainage pipes and open ditches leading from the oil depot to the outside, water seal wells and shut-off devices should be installed on the inside side of the depot’s enclosure; the drainage channels between these water seal wells and the enclosure should be constructed as hidden ditches or pipes ； The water seal height in the water seal well should not be less than 0.25 m ； Water-sealed wells shall be provided with a sediment trap section. Measured from the lowest pipe bottom, the depth of this sediment trap section shall not be less than 0.25 m. Article 7.3.6 of the “Code for Fire Protection Design of Petrochemical Enterprises” (GB50160-2008) stipulates that the production wastewater pipelines within a tank farm shall have independent discharge outlets; a water seal shall be installed outside the fire dike, and easily operable isolation valves shall be fitted on the pipelines located between the fire dike and the water seal. 10.2 Oil spill and accidental wastewater collection: An oil spill and accidental wastewater collection system shall be installed within the collection area ； The collection system can consist of a tank farm fire dike, the low-lying area between the embankment-type fire lanes surrounding the tank farm and the fire dike, a rainwater collection system, and tanks for collecting oil leaks and wastewater from accidents ； The capacity of the oil spill and accident wastewater collection ponds at Class I oil storage facilities shall not be less than 1,000 m³ ； Oil leakage and accident wastewater collection ponds should be located in the lower areas of the reservoir site ； Oil separation measures should be implemented in oil leakage and accident wastewater collection tanks ； Where there are pipelines for flammable and combustible liquids outside the fire dike, the ground should slope towards the rainwater collection system as close as possible ； When underground pipes are used for the main conduits of rainwater collection systems, metal pipes should be preferred ； A water seal well should be installed at the point where the rainwater underground pipe or a branch of the rainwater gutter connects to the main rainwater pipe or gutter. 11. Electrical Systems 11.1 Emergency power supplies for use by the information system should be installed in first-class oil depots ； Primary oil depots equipped with electric valves (except for the control valves used for the quantitative loading of flammable and combustible liquids) should be fitted with portable emergency power supply units. The dedicated switching device for these emergency power supply units should be located in the power distribution room or outside the fire dike surrounding the tank farm ； The power supply for oil depots should preferably come from an external power source ； Emergency lighting should be provided in the fire pump stations and foam stations of Class I oil depots. Batteries can be used as a backup power source for this emergency lighting, with a continuous power supply duration of no less than 6 hours ； The distribution cables in the main production areas of oil depots should be copper-core cables, and they should be laid by direct burial or in cable trenches filled with sand; where it is necessary to lay the cables on the surface in certain areas, flame-retardant cables should be used ； Cables shall not be laid in the same trench as pipes for flammable and combustible liquids or thermal pipelines. Article 9.1.2 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that fire pump rooms and their power distribution rooms shall be equipped with emergency lighting for fire fighting; batteries can be used as a backup power source, with a continuous power supply duration of not less than 30 minutes. 11.2 Lightning Protection 11.2.1 Requirements for Lightning Protection Grounding Steel storage tanks must be equipped with lightning protection grounding, and there should be no fewer than 2 grounding points ； The spacing between the grounding points of steel storage tanks along the perimeter of the tank should not exceed 30 m, and the grounding resistance should not be greater than 10 Ω ； When the top plate thickness of fixed-roof steel storage tanks on the ground is 4 mm or greater, lightning rods (nets) shall not be installed ； Steel storage tanks with a roof thickness of less than 4 mm shall be equipped with lightning rods (nets), which shall protect the entire tank ； External floating roof tanks or internal floating roof tanks should not be equipped with lightning rods (nets), but two wires should be used to electrically connect the floating roof to the tank body. Article 9.2.3 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that floating roof tanks and internal floating roof tanks do not require lightning rods or wires; however, the floating roof must be electrically connected to the tank body using two soft copper wires with a cross-sectional area of not less than 25 mm2. 11.2.2 For floating roof storage tanks with lightning protection connection wires, flat tinned soft copper stranded wire or soft copper stranded wire with an insulated flame-retardant sheath should be used, with a cross-sectional area of not less than 50 mm2 ； The connecting wires for internal floating roof storage tanks should be stainless steel wire ropes with a diameter of not less than 5 mm ； For external floating roof storage tanks, an electrical connection between the tank body and the floating roof should be established using floating roof drain pipes; the bonding wire for each drain pipe should be a flat tinned soft copper stranded wire with a cross-sectional area of not less than 50 mm2 ； On both sides of the rotating ladder of an external floating roof tank, two electrical connections should be made to each of the tank body and the floating roof. 11.2.3 Lightning protection for instrument cables: The wiring cables for instruments and control systems installed on above-ground steel storage tanks should be shielded cables, and they should be protected by galvanized steel pipes; the ends of these protective pipes should be electrically connected to the tank body ； Signal cables in oil depots should be laid underground, and shielded cables are preferred ； When armored cables are used, the armored metal at both the beginning and end of the cable should be grounded ； When the cable is laid in a steel pipe, the steel pipe should be grounded at the point where it enters the building ； The metal enclosure of the signal transmission instrument installed on the storage tank shall be electrically connected to the tank body. Article 9.2.4 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that measuring devices for parameters such as temperature and liquid level of flammable liquid storage tanks shall use armored cables or steel pipes for wiring, and the cable insulation or wiring conduit shall be electrically connected to the tank body. 11.2.4 Lightning protection for loading/unloading trestles (platforms): For loading and unloading operations carried out in the open air, it is not necessary to install lightning rods (nets) ； When loading and unloading operations are carried out inside a shed, lightning protection nets should be used ； The pipelines for transporting flammable liquids that enter the liquid loading/unloading area should be grounded at the point of entry, with the grounding resistance not exceeding 20Ω. 11.2.5 Lightning protection for process pipelines: The metal flange joints of process pipelines should be bonded together; when there are no less than 5 bolts used for connection, bonding is not required in non-corrosive environments ； For metal pipes laid parallel on the ground or in non-sand-filled trenches, when the clear distance between them is less than 100 mm, metal wires should be used for bridging; the distance between the bridging points should not exceed 30 m. When the clear distance at the intersection of pipes is less than 100 mm, metal wires should also be used to bridge those intersections. 11.3 Antistatic measures 11.3.1 Antistatic measures for external floating roof storage tanks The automatic vent valves, breathing valves, flame arresters, and level gauges on external floating roof storage tanks should be electrically connected to the floating roof ； When a type I rubber scraper is used for the secondary seal, each conductive plate shall be electrically connected to the floating roof ； For electrical connections, stranded soft copper wire with a cross-sectional area of at least 10 mm2 and tin plating should be used ； A set of device for eliminating static electricity from the human body is installed 1.5m away on each side of the sampling port on the floating roof, and it must be electrically connected to the tank. This device can also serve as an electrical connection point for tools such as sampling ropes and measuring rods used during manual inspections. 11.3.2 Antistatic measures for railway loading and unloading facilities: The rails, process pipelines, dip pipes, and steel trestles used in railway tank car loading and unloading platforms should be connected together at equal potential points and grounded; the distance between two such connection points should not exceed 20 m, and the grounding resistance of each set should not be greater than 10 Ω. Article 3.2.11 of the \"Technical Specifications for Anti-static Safety\" (Q/SY 1431-2011) stipulates that after oil filling is complete, it is necessary to allow the mixture to stand for at least 2 minutes before carrying out tasks such as removing the dip pipe, taking samples, measuring temperature, checking volume, and removing grounding wires ； The stack should be equipped with a dedicated static grounding wire for the tank truck; the connection between this wire and the tank truck must be completed before the lid is opened. The connection must be tight and reliable, and winding connections are not allowed. The distance between the connection point of the static grounding wire and the opening of the tank truck should be greater than 1.5 meters. The connection wire can only be removed after the required settling time has passed and the lid has been closed. 11.3.3 Antistatic measures for vehicle loading and unloading facilities: For road tankers carrying Class A and Class B liquids, an antistatic grounding device that is connected to the tanker itself shall be installed. Article 3.2.12 of the \"Technical Specifications for Anti-static Safety\" (Q/SY 1431-2011) stipulates that after oil filling is complete, it is necessary to allow the mixture to stand for at least 2 minutes before carrying out tasks such as removing the dip pipe, taking samples, measuring temperature, checking volume, and removing grounding wires ； The loading platform should be equipped with an electrostatic grounding wire specifically designed for tank trucks. The connection between this wire and the tank truck must be completed before the lid is opened; the connection must be tight and reliable, and winding connections are not allowed. The electrostatic grounding wire should be connected to the dedicated grounding terminal on the tank truck, with a distance of more than 1.5 meters between that terminal and the loading/unloading port. The connection can only be removed after the required settling time has passed and the lid has been closed. 11.3.4 Anti-static measures for process pipeline facilities: At the starting and ending points, branching points of process pipelines laid above ground or in non-sand-filled trenches, as well as every 200 m to 300 m along the straight sections, grounding devices for preventing static electricity and lightning-induced electromagnetic pulses should be installed. The grounding resistance should not exceed 30 Ω, and the grounding points should preferably be located at fixed pipe piers (supports). Article 9.3.3 of the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008) stipulates that pipeline pumps, as well as the permanent filters and buffers at the pump inlets, shall be equipped with static electricity grounding facilities. Article 3.2.2 of the \"Technical Specifications for Anti-static Safety\" (Q/SY 1431-2011) stipulates that it is strictly prohibited to use compressed air for blending petroleum products of Class A and Class B. Article 3.2.4 stipulates that when the water content in liquid petroleum products is between 0.5% and 5%, the inflow velocity into the tank must not exceed 1 m/s. 11.3.5 Static electricity elimination devices: Static electricity elimination devices shall be installed in workplaces such as outside the pump rooms for Class A and B liquids, at the entrances to the ladder accessways leading to the tops of storage tanks, and at the entrances to the ladder accessways on the operation platforms within the loading and unloading areas. Article 3.5 of the \"Technical Specifications for Anti-static Safety\" (Q/SY 1431-2011) stipulates that operators shall wear anti-static work clothes and anti-static work shoes, and static electricity on their bodies must be discharged before starting work; the device used for discharging static electricity from the body should be a intrinsically safe type of static electricity eliminator ； Anti-static sampling temperature measurement ropes and anti-static measuring rods should be used; during operation, the ends of these ropes and rods must be properly grounded ； Sampling, measuring dimensions, and taking temperature readings during dynamic processes should be prohibited, and sufficient settling time must be ensured ； During sampling, measuring length, and temperature measurement operations, the upward speed should not exceed 0.5 m/s, and the downward speed should not exceed 1 m/s ； The anti-static sampling rope has a usage period of three months; its use beyond this period is prohibited ； If abnormalities such as decoloration, wear, or breakage of dark fibers are observed during the use of the anti-static sampling rope, its use should be discontinued. Section 4.4 stipulates that intrinsically safe human body static electricity eliminators shall be installed in hazardous work areas such as outside the pump room doors, at the entrances to the ladders leading to the top of oil tanks, at the oil tank sampling points (at a distance of not less than 1.5 m from these sampling points), and at the entrances to the ladders on the operation platforms within the loading and unloading areas. 11.3.6 For the anti-static grounding devices used for bridging at loading and unloading areas, anti-static grounding instruments capable of detecting the grounding condition are preferred ； For mobile grounding connections, flexible wires with insulating sheaths are recommended; these wires, connected via explosion-proof switches, link the grounding device to the liquid loading and unloading facilities. The grounding resistance of the anti-static grounding device should not exceed 100Ω ； For lightning protection grounding, anti-static grounding in oil storage facilities, working grounding of electrical equipment, protective grounding, and grounding of information systems, it is advisable to use a common grounding system, with the grounding resistance being determined based on the lowest required value among these ； When a oil depot is equipped with cathodic protection, the grounding material of the common grounding system should not be a material whose corrosion potential is more positive than that of steel ； Breakaway joints for testing grounding resistance in lightning and static electricity protection systems, devices for eliminating static electricity on the human body, as well as fixed grounding devices at automobile tank truck loading and unloading sites, shall not be installed in Zone 1 with explosion hazards. 12. Automatic Control and Telecommunications 12.1 Automatic Control Systems and Instruments 12.1.1 Level Measurement and Remote Transmission Instruments Storage tanks with a capacity of more than 100 m3 should be equipped with level measurement and remote transmission instruments. The continuous level measurement signals should be transmitted to the automatic control system either in analog form or via communication methods. High and low level alarms should be installed within the automatic control system ； The set level for the low liquid level alarm in storage tanks should be such that cavitation does not occur in the pumps. For external floating roof and internal floating roof storage tanks, the set level for the low liquid level alarm (measured from the bottom of the tank) should be at least 0.2 m above the height at which the floating roof touches the bottom of the tank. Article 6.2.23 of the “Code for Fire Protection Design of Petrochemical Enterprises” (GB50160-2008) stipulates that storage tanks for flammable liquids shall be equipped with level gauges and high-level alarms; where necessary, automatic interlock devices for cutting off the feed can also be installed. Article 9.6 of the \"Construction Standards for Finished Oil Depots\" stipulates that magnetic strain gauge level meters or servo level meters in bus mode can be used for measuring the liquid level in oil tanks; the measurement accuracy shall not be lower than ±1 mm. It is advisable to use at least 5 temperature sensors for averaging the temperature, and no local indicator shall be installed next to the tank ； The temperature measurement accuracy should not be lower than ±0.1℃ ； When the volume of a single tank is 10,000 m3 or more, a servo level gauge is recommended for level measurement ； For the high liquid level alarm in oil tanks, a separate liquid level alarm switch should be installed; it is advisable to use an external ultrasonic liquid level switch or a fork-type liquid level switch for this purpose. 12.1.2 High-level and low-level alarm systems and interlocks: Storage tanks for Class A and B liquids with an annual operation frequency of more than 6 times and a capacity of 10,000 cubic meters or more shall be equipped with high-level alarm systems and interlocks; the high-level alarm system shall be capable of simultaneously triggering the shutdown of the control valve on the inlet pipeline of the tank. The set height for the low-low liquid level alarm (measured from the bottom of the tank) should not be lower than the height at which the floating roof touches the bottom; the low-low liquid level alarm should also be capable of triggering the pump to stop simultaneously. The level measurement instruments used for detecting high and low liquid levels in storage tanks should be separate continuous level meters or level switches, and alarms and interlocks should be installed in the automatic control system. 12.1.3 Temperature measuring instruments: Tanks requiring control and monitoring of storage temperature shall be equipped with temperature measuring instruments, and the temperature measurement signals shall be transmitted remotely to the control room. 12.1.4 Automatic control of pumps and valves: For the important process pumps, fire pumps, and control valves in primary oil depots, in addition to being operable on-site, they should also be able to be controlled and their status monitored from the control room ； Pressure measuring instruments should be installed on the outlet pipelines of pumps used for transporting flammable and combustible liquids; these instruments should be capable of providing local readings. In case of primary oil depots, the pressure measurement signals should also be transmitted to the control room. 12.1.5 Toxic gas and flammable gas detectors shall be installed in areas where toxic gas leaks and accumulations may occur, such as pump rooms containing toxic liquids, loading/unloading stations, metering stations, locations where valves for storage tanks are situated, and drainage wells ； Rooms containing Class A and Class B flammable liquid equipment shall be equipped with automatic combustible gas concentration detection and alarm devices ； Flammable gas detectors should be installed in outdoor areas of Class I oil depots where leaks or accumulations of flammable gases may occur, such as pump stations for Class A and B A liquids, loading/unloading stations, metering stations, valve clusters at above-ground storage tanks, and drainage wells. Article 3.0.4 of the \"Design Code for Detection and Alarm of Flammable and Toxic Gases in Petrochemical Industries\" (GB 50493-2009) stipulates that alarm signals shall be sent to on-site alarms as well as to the indication and alarm devices in manned control rooms or on-site operation rooms, with audible and visual alarms provided. Article 3.0.10 stipulates that the combustible gas and toxic gas detection and alarm systems installed on-site at storage and transportation facilities should preferably be powered by an uninterruptible power supply (UPS). Article 4.3.2 stipulates that at small flexible-pipe railway loading and unloading platforms, a detector should be installed at every other parking space on the ground, and the horizontal distance between such detectors and the loading/unloading ports should not exceed 15 m ； A detector should be installed at the railway loading and unloading quay for large-diameter pipelines ； The horizontal distance between the vehicle loading/unloading cranes at the vehicle loading/unloading station and the detectors should not exceed 15 m. Section 5.1.2 stipulates that the alarm system shall have a function for recording historical events. 12.1.6 Fire system monitoring and sequential control: Primary oil depots shall be equipped with dedicated fire monitoring systems, which shall communicate with the depot’s automatic control system via communication interfaces ； A separate I/O card and a separate display operation station should be provided in the fire control system. The start and stop of the fire pumps in Class I oil depots, as well as the opening and closing of the control valves on the fire water pipelines and foam liquid pipelines, should all be able to be controlled remotely from the fire control room. The main control panel should display the operating status of the pumps and the valve position signals of the control valves. 12.1.7 The instruments and computer monitoring management system for UPS settings shall be powered by a UPS uninterruptible power supply, which must provide at least 30 minutes of AC power supply after an interruption in the external power source. 12.1.8 Requirements for the laying of outdoor instrument cables in automatic control systems: Instrument cables laid in the production area should preferably be installed underground using methods such as cable trenches, cable protection tubes, or direct burial; when cable trenches are used, they should be filled with sand to ensure proper sealing ； For cables that must be laid on the surface in certain areas of the production zone, they should be installed using galvanized steel protective pipes or fully enclosed metal cable trays with covers ； In non-production areas, instrument cables can be laid above the ground using fully enclosed metal cable trays. 12.2 Telecommunications 12.2.1 Fixed communication systems: Oil storage facilities should be equipped with fire alarm telephone systems, administrative telephone systems, radio communication systems, and television monitoring systems ； Class I oil depots should also be equipped with a computer local area network, an intrusion alarm system, and an access control system. 12.2.2 In positions involving mobile operations at petroleum storage facilities within mobile communication systems, radio communication equipment should be provided; wireless intercom systems or cluster communication systems are preferred, and the wireless communication handsets must be of explosion-proof type. 12.2.3 Television monitoring system: The coverage of the television monitoring system should include the tank storage area, pump stations for flammable and combustible liquids, facilities for loading and unloading such liquids, as well as the entrances and exits to key facilities ； The TV monitoring operation stations should be located separately in the production control room, fire control room, fire station duty room, and security duty room, among other locations ； When installing an automatic fire alarm system, it is advisable to integrate it with a video surveillance system for coordinated control. 12.2.4 Intrusion alarm system: The intrusion alarm system should be installed along the perimeter fence of the oil depot, with the alarm control unit preferably located in the guard room or security office ； An intrusion alarm system should be integrated with a video surveillance system to form a security alarm platform. 12.2.5 Computer Local Area Network: The computer local area network shall meet the requirements for data communication and information management system development in oil depots. 13. Heating and Ventilation 13.1 Heating The heating temperatures for various rooms in the oil depot are shown in Table 10: Table 10 Heating Temperatures for Various Rooms in the Oil Depot Sequence Number Room Name Heating Temperature (°C) 1 Pump room 5 2 Metering room, instrument room, laboratory, office, duty room, lounge 18 3 Washroom 14 4 Toilet 12 5 Bathroom, changing room 25 6 Changing room 23 13.2 Ventilation 13.2.1 Ventilation in the Pump Room The pump room should be equipped with a mechanical ventilation system as well as an emergency exhaust system. The air exchange rate of the mechanical ventilation system should be 5–6 times per hour, while the air exchange rate of the emergency exhaust system should not be less than 12 times per hour. 13.2.2 Ventilation fans should be driven by direct drive or coupling, and anti-static measures should be taken for air ducts, fans, and their installation methods. 13.2.3 Integration of ventilation and combustible gas detection alarm systems: In rooms equipped with equipment containing Class A and Class B liquids, the mechanical ventilation systems installed there should be integrated with the automatic combustible gas concentration detection alarm system, and local as well as remote manual activation devices should be provided. 14. Starting and ending points for calculating spacing: The starting and ending points for calculating spacing are shown in Table 11: Table 11 Starting and Ending Points for Calculating Spacing. Sequence Number; Buildings, structures, facilities, and equipment; Starting and ending points for calculating spacing: 1. Roads – Road edge; 2. Railways – Centerline of the railway track; 3. Pipelines – Center of the pipe; 4. Above-ground vertical storage tanks and above-ground horizontal tanks – Outer wall of the tank; 5. Various equipment installed outdoors (including under shelters) – Most prominent outer edge; 6. Overhead power and communication lines – Center of the line; 7. Buried power and communication cables – Center of the cable; 8. Buildings or structures – Axis of the outer wall; 9. Railway tank car loading and unloading facilities – Centerline of the railway tank car loading and unloading track, as well as the center of the loading/unloading fittings on the end tanks; 10. Road tank car loading and unloading facilities – Center of the hose or pipe nozzle during road tank car loading and unloading operations; 11. Overhead power (communication line) poles/towers – Height from the ground level to the top of the pole/tower. Conclusion: Based on the data provided in these standards and specifications, it is evident that the existing facilities in the storage and transportation workshop fall far short of the required standards in terms of fire safety, automation, and environmental protection. In particular, the projects aimed at addressing the hazards in the storage area, which are currently in the design phase, still lack proper measures in terms of fire safety and monitoring/control of storage tanks. It is hoped that this compilation of standards and specifications can serve as a starting point, providing some reference for the overall planning of the South Station storage area. It is sincerely hoped that the efforts invested in addressing the hazards in this area will result in solutions that meet all relevant standards.