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1 General provisions
1.0.1 This part of this specification is formulated with a view to improving the engineering design quality of chemical plant and standardizing the equipment layout design.
1.0.2 This part is applicable to the equipment layout design of constructed, extended or renovated process plants in the chemical industry. Petroleum, petrochemical, textile, pharmaceutical and other industries may refer to this part.
1.0.3 In addition to this part and the other four parts (HG/T 20546.1, and HG/T 20546.3~HG/T 20546.5) of this specification, the equipment layout design shall also comply with those stipulated in the current relevant standards of the nation.
2 Emphasis of layout
2.1 Process and flow requirements
2.1.1 The equipment layout design shall meet the requirements of the process flow. For example, the equipment of vacuum, gravity-flow and solid discharges, etc. shall be all arranged according to the elevation requirements of piping and instrumentation diagram (P&ID). The equipment for treating corrosive, toxic and viscous materials should be arranged compactly according to the properties of materials. If necessary, measures such as arranging a separation barrier should be taken. The equipment layout shall also be based on the terrain, the annual minimum frequency wind direction and other conditions so as not to affect the process requirements. For example, air intake and circulating water cooling tower, etc.
2.2 Environmental protection, fire protection, explosion prevention, labor safety and health and occupational safety and health requirements
2.2.1 The fire separation distance of equipment, buildings and structures shall strictly comply with the current regulations, specifications on fire protection. The supporting utility works and auxiliary facilities, if any, in the process plant shall be arranged as an area, which is located outside the explosion hazardous area and has a fire separation distance with the process plant. Attention shall be paid to environmental protection. The equipment using, storing and producing toxic materials or causing serious pollution should be arranged in zones. The equipment producing noise should be arranged in isolation from other equipment to prevent pollution and noise. The plants and equipment with high fire and explosion hazard and harmful gas emission shall be arranged in the open air or in a semi-open way as far as possible, so as to relatively reduce their hazard, toxicity and accident destructiveness. Equipment shall be arranged in zones according to the division of hazard level.
The layout of electrical equipment using electric energy or motors shall meet the requirements of the current standard GB 50058 Electrical installations design code for explosive atmospheres and fire hazard of the nation. The auxiliary buildings such as centralized control room, substation and power distribution room, laboratory and office of the plant shall be arranged outside the explosion hazardous area and close to the edge of the plant area.
To locate the equipment with open flame and the control room and power distribution room, the annual minimum frequency wind direction shall be taken into account. The plant with fired equipment should be arranged on the leeward side of the annual minimum frequency wind direction of the plants that may emit combustible gas as well as the liquefied hydrocarbon and flammable liquid storage tank areas. The flue gas discharged from chimney shall not be blown to compressor room or control room. The power distribution room should be arranged on the windward side of the place where inflammable and explosive gases can leak out.
In terms of labor safety and health and occupational safety and health, the principle of "safety for production, production must be safe" and the health policy of "prevention first" must be implemented.
2.3 Ease of operation
2.3.1 The plant layout shall be considered to create a good operating environment for the operator, mainly including: necessary operating accesses and platforms; stairs and safety entrances and exits meeting the specification requirements; reasonable arrangement of equipment distance and clearance height, etc.
The location of the control room shall be reasonable, and shall avoid hazardous areas and be away from vibrating equipment, so as not to affect the operation of instruments.
2.4 Ease of installation and maintenance
2.4.1 For the purposes of the installation and maintenance of equipment, movable lifting equipment shall be adopted as far as possible. The following requirements shall be met in the layout design stage:
1 The entrance/exit and clearance height of roads shall be convenient for mobile cranes to enter and exit;
2 The floor area and space required for handling and hoisting;
3 Cleaning site for fillers in equipment;
4 The ability to overhaul all equipment at the same time during scheduled overhauls;
5 There shall be enough space for tube bundle extracting of heat exchangers and heating furnaces, and it shall be avoided to extend to adjacent accesses when pulling out the tube bundles. Adequate maintenance areas shall also be provided for the maintenance and replacement of rotating equipment components such as compressor drivers.
2.4.2 Fixed maintenance equipment is required for the following occasions:
1 The manhole cover shall be provided with a davit;
2 The tower plate and the internal components of the tower shall be provided with davits;
3 The indoor compressors, turbines, etc. shall be equipped with cranes; for small compressors, simple lifting facilities may be provided as appropriate;
4 The mixer in the building shall be equipped with a lifting beam or crane.
2.5 Economic rationality requirements
2.5.1 The equipment layout shall be economical and reasonable on the premise of meeting the process requirements, and shall also be neat and aesthetical. Except for pipelines with requirements for thermal expansion, the pipelines shall be considered as short and straight as possible in equipment layout, and some equipment may be arranged for economic purposes without following the process.
2.5.2 In order to be neat and aesthetical, equipment may be arranged in the following ways:
1 For towers arranged in rows, a joint platform may be arranged if possible;
2 When the heat exchangers are arranged side by side, they should be aligned with the centerline of the tube side connecting pipe on the pipe rack side;
3 The centrifugal pumps shall be aligned with the centerline of pump outlet pipe;
4 Horizontal vessels should be aligned with the tangent line of the seal head on the pipe rack side; heating furnace, reactor, etc. should be aligned with the centerline.
3 Clear distance, clearance and relevant elevations
3.1 Minimum clear distance between equipment
3.1.1 The clear distance between equipment shall first meet the requirements of fire separation distance, as detailed in GB 50160 Fire prevention code of petrochemical enterprise design and GB 50016 Code for fire protection design of buildings, which shall be the current valid versions.
3.1.2 See Table 3.1.2 for the equipment distance that is not determined by fire protection factors or is not specified in the fire protection code.
Table 3.1.2 Minimum clear distance between equipment or
between equipment and buildings (or obstacles)
Zone Content Minimum clear distance (mm)
Between control room/power distribution room and heating furnace 15,000
Under or on both sides of pipe rack Between two towers (considering arranging platform, not considering the foundation size)
Between the outer wall of tower equipment and the column of pipe rack (or structure)
Between the vessel wall or the end of heat exchanger and the column of pipe rack (or structure)
Maintenance access between two rows of pumps
Between two adjacent pumps (considering foundation and pipeline) 2,500
3,000
2,000
3,000
800
Inside the building Maintenance access between two rows of pumps or between single row of pumps and wall
Between the end face or foundation of pump and the wall or column 2,000
1,000
Any zone Operating, maintenance and escape accesses
Maintenance clear distance between two horizontal heat exchangers
Clear distance between two horizontal heat exchangers during operation (considering valves and pipes)
Between the shell of horizontal heat exchanger (lateral) and the wall or column (during passing)
Between the shell of horizontal heat exchanger (lateral) and the wall or column (during maintenance)
Clear distance in front of seal head of horizontal heat exchanger (axial)
Clear distance around flanged edge of horizontal heat exchanger
Clear extraction distance of heat exchanger tube bundle (L: tube bundle length)
Two horizontal vessels (parallel, no operation)
Between two vessels
Between the foundation of vertical vessel and the wall
Distance between the manhole of vertical vessel and the platform edge (side)
Between the flange of vertical heat exchanger and the platform edge (maintenance clear distance)
Around the compressor (maintenance and operation)
Compressor
Reactor and heating furnace for providing reaction heat 800
600
750
1,000
600
1,000
450
L+1,000
750
1,500
1,000
750
600
2,000
2,400
4,500
3.2 Appropriate clearance height or vertical distance
3.2.1 The appropriate clearance height or vertical distance shall be in accordance with those specified in Table 3.2.1.
1 General provisions
2 Emphasis of layout
2.1 Process and flow requirements
2.2 Environmental protection, fire protection, explosion prevention, labor safety and health and occupational safety and health requirements
2.3 Ease of operation
2.4 Ease of installation and maintenance
2.5 Economic rationality requirements
3 Clear distance, clearance and relevant elevations
3.1 Minimum clear distance between equipment
3.2 Appropriate clearance height or vertical distance
3.3 Elevation
3.4 Appropriate width of road and operating access
4 Operating platform and ladder
4.1 Operating platform
4.2 Ladders
5 Other requirements of layout design
5.1 Height of vent nozzle
5.2 Piping
5.3 Pipe trench and sewage well
5.4 Drain pipes and sewers
5.5 Paved ground and slope
