Shenzhen Zhongnuo Testing Technology Co., Ltd. is based in South China and offers explosion-proof technology consulting services, including on-site explosion-proof construction, safety inspections, renovations, project acceptance, and installation. We are well-versed in explosion-proof construction standards, with experienced construction teams and a wealth of experience. We have served large corporations such as PetroChina, LG, Hanlan Environment, BOE, 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 controlled temperature and humidity, as well as cleanliness; while workshops that are hot or dust-laden require excellent ventilation and dust removal systems. For industrial enterprises in the chemical, pharmaceutical, and petrochemical sectors, due to the risk of explosions during the production process, 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 Inspection Technology Co., Ltd. shares its views on the design of buildings for explosive areas and electrical wiring systems, for your reference only.
Basic technical measures for explosion-proof in factory building design
(1) For factories (such as plants) with explosive hazards across the entire industrial area, the overall planning and design should consider factors like the production processes, product types, production characteristics, and degree of danger of hazardous materials within the buildings. After determining the hazard level of the buildings, zoning planning should be carried out. The distances 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 hazard level of the buildings and the amount of stored materials, and the maximum value should be taken in accordance with regulations. If the required distances cannot be met due to factory site limitations, protective barriers must be installed, such as protective embankments or reinforced concrete walls. Protective barriers are mandatory for Class A buildings. The layout should be adapted to the local conditions, making full use of the terrain and地貌 to achieve an optimal and reasonable arrangement.
(2) For buildings and workshops within general industrial zones that produce and utilize products, it is advisable to cluster them within the same area. The distance between these buildings and workshops should meet the safety requirements for a safe distance. This facilitates the unified handling of firewalls and other explosion-proof structural elements.
(3) Workshops with explosive hazards should be located in single-story buildings. If the workshop must be multi-story due to process requirements, it should be situated on the upper floor.
(4) When a local explosion-proof room is provided in general factory buildings or workshops, it 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 hazards should be separated by sturdy fire-resistant walls (brick or reinforced concrete walls). It is advisable to open doors on the exterior walls to facilitate communication between workshops using external corridors or balconies; or create a double-door vestibule on the fire-resistant wall, attempting to stagger the doors as much as possible to mitigate the impact of the explosion shock wave and reduce the range of the explosion's effects.
(6) For equipment prone to explosion, it should be placed as close to the outer wall and windows as possible, or outdoors, to minimize its destructive force.
(7) Production and storage of hazardous materials of different nature should be separately arranged, such as those that must be separated from oxygen.
(8) Do not locate the hazardous explosive areas in basements or semi-basements due to poor ventilation, which can cause significant impact during accidents and is不利于 evacuation and rescue efforts.

As the global energy and chemical industry expands, construction in explosive hazardous environments becomes increasingly widespread, making the prevention and acceptance of such environments even more crucial.
Especially in flammable dust environments such as plastic factories, feed/food/cereal processing plants, metal polishing and polishing workshops, and papermaking/forestry wood powder/fiber dust factories, the number of projects involving explosion-proof installations, designs, and renovations is also increasing.
Whether it's large-scale explosion-proof or local explosion-proof, if there are hidden dangers in product quality or installation/renovation quality,
Our personnel and property safety is greatly threatened, so we must control the quality at every production process, ensuring the reliability and safety of explosion-proof installations and renovations.
Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof construction and retrofitting consultation services, boasting rich qualifications and case studies—worth it!

Basic knowledge for explosion-proof electrical installation includes the following points:
Explosive materials classification, grouping, and classification of explosive hazard areas, as well as the delineation of regional scope.
Explosive gases should be classified based on their Maximum Experimental Safe Gap (MESG) or Minimum Ignition Current Ratio (MICR), and grouped by ignition temperature. Combustible dusts, categorized by their conductivity, can be divided into conductive and non-conductive types, and grouped by their low ignition temperature. Hazardous areas involving explosive substances are divided into two categories: gas explosion hazardous areas and dust explosion hazardous areas. These areas are further classified into three zones (0, 1, and 2) based on the frequency and duration of the presence of explosive gas environments. For combustible dust/air mixtures, the zones are classified into three levels (20, 21, and 22) based on the frequency and duration of occurrence and the thickness of the dust layer.
2. Selection of explosion-proof electrical equipment for hazardous explosive areas.
The selection principles for explosion-proof electrical equipment are safety and reliability, as well as economic and reasonable. Selection should be based on the grade of the explosive hazard area and the type, grade, and group of explosive hazardous materials. Refer to the specific selection table in standard AQ3009-2007 for details.
3. Installation of electrical wiring and explosion-proof electrical equipment in hazardous explosive areas.
Installation methods for electrical wiring in explosive gas environments can be divided into cable wiring and conduit wiring. Electrical wiring should be laid in areas with lower explosion hazards or at a greater distance from the source of release, avoiding locations prone to mechanical damage, vibration, corrosion, dust accumulation, and those with dangerous temperatures. When avoidance is not possible, preventive measures should be taken. The low-voltage cables or insulated conductors used must have a rated voltage higher than the working voltage of the circuit and not less than 500V. Insulated conductors must be laid inside conduits, etc. For specifics, please refer to training programs for explosion-proof electrical installation, maintenance, and repair.
Four: Inspection and maintenance of explosion-proof electrical equipment in hazardous areas.
To minimize the ignition hazard of electrical equipment in hazardous areas, initial inspections should be conducted before the equipment is put into operation, during the handover and acceptance of the project. To ensure the electrical equipment remains in good condition for long-term use in hazardous areas, continuous supervision and regular inspections should be carried out. Initial and regular inspections should be entrusted to safety production testing and inspection institutions with explosion-proof qualifications.
Inspections and maintenance of explosion-proof electrical equipment should be conducted by qualified personnel meeting specified criteria. These individuals must undergo training covering general principles such as explosion-proof types, installation practices, relevant regulations and procedures, and classification of hazardous areas. They should also receive appropriate continuing education or regular training and possess relevant experience and trained qualifications. Continuous supervision and periodic inspections should be implemented. Maintenance requirements should propose reasonable corrective actions and equipment replacement measures.

Protection of explosive loop circuits shall comply with the following regulations (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
In the single-phase network within Zone 1, both phase wires and neutral lines should be equipped with short-circuit protection, and appropriate switches should be used to simultaneously disconnect both phase wires and neutral lines.
(2) For 3kV-10kV cable lines, it is advisable to install zero-sequence current protection, and the protective devices in Zones 1 and 21 should be set to trip.
Explosion-proof electrical modifications and on-site explosion-proof construction consulting services for hazardous areas — Shenzhen Zhongnuo Testing Technology Co., Ltd.