Shenzhen Zhongnuo Testing Technology Co., Ltd. is based in South China, offering explosion-proof construction, safety inspections, renovations, project acceptance, and installation services. We are well-versed in explosion-proof construction standards, boasting experienced construction teams and a wealth of practical experience. We have served major corporations such as PetroChina, LG, Hanlan Environment, BOE Technology Group, and Sinovac Biotech, receiving consistent praise and trust from our clients!
In the design of industrial factory buildings, different production processes have varying requirements for the structures. Production facilities for precision instruments and equipment necessitate constant temperature, humidity, and cleanliness; while certain hot workshops and dust-laden areas demand adequate ventilation and dust removal systems. For industrial enterprises in the chemical, pharmaceutical, and petrochemical sectors, due to the risk of explosions during production, the design of the factory buildings must not only meet production process requirements but also carefully consider explosion prevention measures. In the event of an explosion, efforts should be made to minimize the loss of life and property. Shenzhen Zhongnuo Testing Technology Co., Ltd. shares its views on the design of buildings for explosive areas and electrical wiring, for your reference only.
Basic explosion-proof technical measures in factory building design
(1) For factories (such as plants) where the entire facility is at risk of explosion, the overall planning and design should take into account factors like the production processes, types of products, production characteristics, and degree of danger of hazardous materials within the buildings. After determining the danger level of the buildings, zoning planning should be conducted. The distance between buildings within the hazardous material production area and surrounding villages, highways, railways, towns, and the factory's living facilities should be calculated based on the building's danger level and the quantity of stored substances, and the maximum value should be chosen in accordance with regulations. If the required distances cannot be met due to site limitations, protective barriers must be installed, such as protective embankments or reinforced concrete walls. Protective barriers must be set for Grade A buildings. Adapted to the local conditions, make the best use of the terrain and地貌, to achieve an optimal and reasonable layout.
(2) For buildings and workshops within general industrial areas that produce and use products, they should be arranged as concentrated as possible within the same region. The distance from general buildings and workshops should meet the safety requirements, which facilitates the unified handling of fire-resistant walls and other explosion-proof structural elements.
(3) Workshops with explosive hazards should be located in single-story buildings. If multi-story buildings are required due to process needs, they should be placed on the upper floor.
(4) When local explosion-proof rooms are installed in general factory buildings or workshops, these rooms should be as close to the exterior wall as possible. Use specially designed windows that are easy to open outward, which facilitates pressure relief and fire extinguishing.
(5) Within the factory, workshops with high and low levels of danger should be separated by sturdy fire-resistant walls (made of brick or reinforced concrete). It is advisable to open doors on the exterior walls for inter-workshop communication using corridors or balconies; or create double-door vestibules on the fire-resistant walls, trying to stagger the doors as much as possible. Use the vestibules to mitigate the impact of explosion shockwaves and reduce the scope of the explosion's effects.
(6) For equipment prone to explosion, it should be placed as close to the exterior wall and windows as possible, or outdoors, to minimize its destructive force.
(7) Production and storage of hazardous materials of different natures should be separated, such as those that must be kept apart from oxygen.
(8) Do not locate areas with explosive hazards in basements or semi-basements due to poor ventilation, which can greatly impact accidents and is不利 for evacuation and rescue efforts.

Shenzhen Zhongnuo Inspection & Technology Co., Ltd. offers a range of explosion-proof engineering services for hazardous explosive areas.
1. Explosion-proof site inspection and consultation
2. Explosion-proof engineering construction and renovation on-site
3. Explosion-proof Construction Acceptance
4. Explosion-proof electrical installation, maintenance, and renovation
5. Explosion relief, explosion-proof walls, doors, and windows installation
6. Dust Removal Equipment Installation and Retrofitting Construction

Basic Dust Explosion Proof Construction Standards
In facilities where explosive dust is present, such as flour mills, feed factories, grinding workshops, and plastic production plants, the requirement for explosion-proof measures on-site is particularly important. The installation and use of explosion-proof wiring, electrical equipment, dust removal systems, structural layout, and explosion-proof venting must all comply with the relevant dust explosion-proof standards. Based on a wealth of explosion-proof electrical construction and retrofitting cases, Shenzhen Zhongnuo Testing Technology Co., Ltd. has summarized the following points:
Building structure and layout
Process equipment with dust explosion hazards or buildings (structures) containing combustible dust should be separated from other buildings (structures), and their fire protection distances should comply with the relevant provisions of GB50016.
(2) The building should be a single-story structure, with a lightweight roof design preferred.
(3) The structural requirements for multi-story buildings are as follows:
A. Multistorey buildings are best suited for frame structures
B. Buildings without frame structures must have explosion relief openings set on the walls in compliance with requirements.
C. If windows or other openings are used as explosion relief ports, they must be calculated and ensured to effectively vent during an explosion.
(4) The requirements for evacuation routes are as follows:
A. The work area should have evacuation routes, and the number and location of the evacuation routes should comply with the provisions of GB50016.
B. The door should open outward and no threshold should be installed.
C. Detailed signage and emergency lighting should be installed for evacuation routes.
2. Process Equipment
(1) If the process equipment poses a dust explosion risk within the factory, it should be located on a higher floor of the building and close to the exterior wall.
(2) Equipment with explosive hazards should be located in an outdoor area outside of the building.
(3) Equipment or devices in direct contact with dust (such as light sources, heating sources, etc.) should have surface temperatures below the corresponding dust's low ignition temperature.
(4) In areas where combustible dust is present, the transmission mechanisms of the equipment and devices shall comply with the following regulations:
The bearings of the processing equipment should be dust-proof and sealed. If overheating is possible, a detector capable of continuously monitoring the bearing temperature should be installed.
B. Belt drive is not recommended. If belt drive is used, a speed difference sensor and an automatic anti-slip protection device should be installed. In case of sliding friction, the protection device should ensure automatic shutdown.
(5) At the feed point of the process flow, magnets, pneumatic separators, or sieves capable of removing impurities mixed in the material should be installed to prevent collisions between impurities and equipment.
(6) Effective measures should be taken to prevent sparks from being generated when metal powders such as aluminum, zirconium, or powders containing these metals come into contact with stainless steel.
(7) In the event of an explosion, protective stopping should be achieved by installing several power supply control boxes that can interlock with each other, depending on the size of the workshop. In emergency situations, the power supply to all motors should be able to be cut off promptly.
(8) Joints, inspection doors, baffles, and explosion vent covers of the process equipment should all be sealed tightly
(9) The equipment housing should be made of non-flammable material
(10) The moving parts of the equipment should operate smoothly without any scraping, bumping, jamming, or rubbing.
(11) If the strength of the process equipment is insufficient to withstand the overpressure generated by internal dust explosion under actual working conditions, explosion relief ports should be installed, and the size of the relief ports should comply with the relevant provisions of GB/T15605.
(12) The venting port should be located close to potential ignition sources, and it should be as high as possible, ideally at the top or near the top of the containment structure. It must not vent towards flammable or explosive hazardous areas to prevent igniting others, and it must not vent towards public spaces to avoid causing injury from venting explosions.
3. Lightning and Static Electricity Protection
Dust explosion hazardous areas should adopt lightning protection measures in accordance with the relevant provisions of GB50057. When static electricity hazards are present, the following regulations should be followed:
All metal equipment, enclosures, metal pipelines, brackets, components, parts, etc., generally adopt antistatic direct grounding. For those that are not convenient or prohibited by the process from direct grounding, indirect grounding can be achieved through conductive materials or products.
(2) Equipment directly used for containing electrostatic powder, such as conveyance pipes (belts) for the powder, should be made of metal or anti-static materials.
(3) All metal pipe connections should be bonded together.
(4) Operators should take anti-static precautions.
(5) Do not use a method of grounding metal conductors or screens directly to high-speed flowing powders to dissipate static electricity.

Installation of electrical wiring in explosive environments shall comply with the following regulations (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
Electrical wiring should be installed in environments with low explosion hazards or far from the source of release, and it should comply with the following regulations:
1) When the material is heavier than air, electrical wiring should be installed at a higher level or directly buried. For overhead installation, cable trays should be used; for trench installation, the trench should be filled with sand, and drainage measures should be provided.
2) Electrical wiring should be installed outside the walls of buildings or structures that are prone to explosion hazards.
3) In explosive dust environments, cables should be laid in areas where dust does not accumulate easily and is easy to dust off.
(2) Holes in walls or floors between different areas traversed by electrical line trenches, cable trays, or conduits should be tightly sealed with non-combustible materials.
(3) When laying electrical lines, it is advisable to avoid areas prone to mechanical damage, vibration, corrosion, UV radiation, and those that may overheat. If avoidance is not possible, preventive measures should be taken.
(4)钢管 wiring can utilize bare insulated single-core or multi-core conductors. When the steel pipe contains three or more conductors, the total cross-sectional area of the conductors, including the insulation, should not exceed 40% of the steel pipe's cross-sectional area. The steel pipes should be of the type used for low-pressure fluid conveyance with locked zinc焊接. The threaded portion of the steel pipe connections should be coated with lead oil or phosphating paste. In areas where condensation or condensate water may form, sealed joints for draining condensate should be installed on the pipeline.
(5) Electrical wiring for piping in explosive gas environments should be properly insulated and sealed, and shall comply with the following regulations:
1) During normal operation, the 450mm radius around all ignition source enclosures should be sealed off.
2) Steel pipes with a diameter of 50mm or more should be sealed and insulated at a distance of 450mm or less from the incoming junction box.
3) Isolation and sealing should be carried out between adjacent explosive environments, as well as between explosive environments and adjacent other hazardous or non-hazardous environments. When sealing, the inner part of the seal should use fiber as the base or separator layer for the filling. The effective thickness of the filling should not be less than the inner diameter of the steel pipe, and should not be less than 16mm.
4) Connection components for isolation sealing should not be used for wire connections or branching.
(6) Intermediate joints are strictly prohibited on cable lines within Area 1, and intermediate joints should not be present in Areas 2, 20, and 21.
(7) When connecting the ends of cables or wires, if the internal wires are stranded, the ends should be connected using a molded terminal or a crimped connector. The connection and termination of aluminum-core insulated wires or cables should be done by crimping, soldering, or brazing. When connecting to equipment (excluding lighting fixtures), a copper-aluminum transition connector should be used.
(8) Overhead power lines must not cross explosive gas environments. The horizontal distance between overhead lines and explosive gas environments should not be less than 1.1 times the height of the tower. In special cases, after taking effective measures, the distance may be appropriately reduced.
Explosion-proof electrical retrofitting in hazardous areas and on-site explosion-proof construction consulting services - Shenzhen Zhongnuo Testing Technology Co., Ltd.