Shenzhen Zhongnuo Testing Technology Co., Ltd. is based in South China, offering consulting services for explosion-proof construction, safety inspections, renovations, project acceptance, and explosion-proof installations. We are well-versed in explosion-proof construction standards, boast experienced construction teams, and have served major corporations such as PetroChina, LG, Huanlan Environment, BOE, and Sinovac Biotech, receiving consistent praise and trust from our clients!
Basic Dust Explosion-proof Construction Regulations
In facilities where explosive dust is present, such as flour mills, feed factories, grinding workshops, and plastic production plants, the requirement for explosion-proofing on-site is particularly crucial. 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 modification cases, Shenzhen ZhongNuo Testing Technology Co., Ltd. has summarized the following points:
1. Structure and layout of buildings
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. Multi-story buildings are best suited for frame structures.
B. Buildings not using frame structures must be equipped with explosion relief openings in accordance with the 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 these routes should comply with the relevant provisions of GB50016.
B. The door should open outward and no threshold shall be installed.
C. Detailed signage and emergency lighting should be provided for evacuation routes.
2. Process Equipment
If the process equipment in the factory has a dust explosion hazard, it should be located at a higher level of the building and near the outer wall.
(2) Equipment with explosive hazards should be located in an outdoor area outside the building.
(3) Equipment or devices that come into direct contact with dust (such as light sources, heating sources, etc.) should have surface temperatures below the respective dust's low ignition temperature.
(4) In areas where combustible dust is present, the transmission mechanisms of the equipment and installations shall comply with the following requirements:
The bearings of the process equipment should be dust-proof and sealed. If there is a possibility of overheating, 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, magnets, pneumatic separators, or sifters 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 through friction between metal powders such as aluminum, zirconium, or powders containing these metals with stainless steel.
(7) In the event of an explosion, protective stoppage should be achieved. Several power supply control boxes capable of interlocking should be installed based on the size of the workshop. In emergencies, the power supply to all motors should be promptly disconnected.
(8) All connections, inspection doors, baffles, and explosion relief cover plates of the process equipment should 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) When 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 set, and the size of the relief ports should comply with the relevant provisions of GB/T15605.
(12) The explosion relief port should be located near potential ignition sources and should ideally be placed at the top or upper part of the containment structure. It must not vent towards flammable and explosive hazard areas to prevent igniting others, and it must not vent towards public areas to avoid causing injury from the explosion.
3. Lightning and static electricity protection
Hazardous dust explosion areas should adopt corresponding lightning protection measures in accordance with the relevant provisions of GB50057. When static electricity hazards are present, the following regulations should be followed:
(1) All metal equipment, device casings, metal pipes, brackets, components, and parts, etc., are generally equipped with anti-static direct grounding. For those that are not convenient or not allowed to be grounded directly due to the process, 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 antistatic materials.
All metal pipe joints should be bonded across.
(4) Operators should take anti-static precautions.
(5) Do not use metal conductors or mesh screens in direct contact with high-speed flowing powder to dissipate static electricity.

Basic Knowledge and Requirements for防爆 Cable Usage at Construction Sites (Shared by Shenzhen Zhongnuo Testing Technology Co., Ltd.)
Installation methods for electrical wiring in explosive gas environments can be divided into cable wiring and conduit wiring methods.
Note: The installation of inherently safe circuits may not be in accordance with this provision.
7.1 General Provisions
7.2 Electrical wiring should be installed in areas with lower explosion hazard 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.
7.3 The selected low-voltage cables or insulated conductors must have a rated voltage higher than the working voltage of the line, and not less than 500V. Insulated conductors must be laid inside conduits.
7.4 Prohibition on crossing explosive gas environments for overhead lines with voltage of 10kV and below; the horizontal distance between the overhead line and the explosive gas environment should not be less than 1.1 times the height of the pole tower.
7.5 Cables and their accessories should be installed in a position that prevents them from being damaged by external mechanical forces, corrosion, or chemical influences (such as the effects of solvents), as well as the effects of high temperatures (also see 6.1.2.4.4 for this safety circuit). If such conditions cannot be avoided, protective measures should be taken during installation, such as using conduits or selecting the cable type (armored cables, shielded wires, seamless aluminum sheathed cables, mineral insulated metal sheathed cables, or semi-rigid sheathed cables, etc., to minimize damage).
7.6裸单芯电线，unless installed within a distribution board, enclosure, or conduit system, shall not be used for conductive wiring.

Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof construction service in the field of:
Explosive gas environments and hazardous areas with explosive or flammable dust exist in various industries and fields, including petrochemicals, metal smelting, fine chemicals, petrochemical ground facilities (such as gas stations, filling stations, and petrochemical storage and transportation), new energy, special equipment, nuclear power, tunnels, grain processing, wood processing, metal parts manufacturing, environmental protection engineering, and more. Ensuring explosion-proof safety in these dangerous areas safeguards the防爆 safety of high-risk explosive environments for both our and the national economy's development.

Based on the fundamental requirements of GB 15577 "Safety Code for Dust Explosion Prevention," the implementation of explosion-proof construction and modification in explosive dust environments primarily involves the following five major explosion-proof measures (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.).
Explosion-proof
1. Definition: A explosion suppression technology that enables the containment to withstand the pressure of a large explosion when an explosion occurs within an enclosed space with combustible dust and gaseous oxidizers or air, thus preventing the containment from being destroyed.
2. Objective: By enhancing the container wall thickness and improving the material, external damage is minimized even in the event of a dust explosion.
3. Basic Requirements:
When producing and handling powdered materials that can cause explosions, if there is no explosion suppression device and no pressure relief measures, all process equipment should be designed to be explosion-proof and capable of withstanding the overpressure generated by internal explosions without bursting.
(2) The connecting parts between various process equipment (such as pipes, flanges, etc.) should have the same strength as the equipment itself. For connections between high-strength and low-strength equipment, explosion-proof devices should be installed.
(3) Equipment for explosion-proof pressure and explosion-proof pressure impact should meet the requirements of GB/T 24626.
Explosion Relief
1. Definition: A controlled explosion technology that, during an explosion within the containment vessel, allows the high temperature, high-pressure combustion products, and unburned materials generated by the explosion to be vented through pre-set weak points in the containment vessel to a safe direction before the explosion pressure reaches the vessel's limit strength, thereby preventing the vessel from being destroyed.
2. Purpose: To reduce explosion losses by setting up explosion relief devices.
3. Methods: Two explosion relief methods are available: Flaming and Non-flaming.
4. Basic Requirements:
When the strength of the process equipment is insufficient to withstand the overpressure generated by internal dust explosion under actual operating conditions, a venting port should be installed. The venting port should be directed towards a safe direction, and the size of the venting port should comply with the requirements of GB/T 15605.
(2) Indoor dust explosion hazard process equipment should be vented to a safe outdoor direction through pressure relief conduits. These conduits should be as short and straight as possible, with a cross-sectional area not less than that of the relief port, and their strength should not be less than the strength of the protected equipment container.
(3) Equipment within the room that cannot vent its explosion to the outdoors through a pressure relief conduit should be fitted with flameless explosion venting caps.
(4) Process equipment with inline piping should be designed to withstand at least 0.1 MPa of internal overpressure.
Three, explosion suppression
1. Definition: In the initial stage of an explosion, extinguishing the flame and inhibiting (preventing) the development of dust explosion through physical and chemical actions.
2. Objective: To pre-detect fire extinguishing and explosion suppression through the installation of explosion suppression devices.
3. Basic Requirements:
Process equipment with a risk of dust explosion should be protected with explosion suppression devices.
(2) If a monitored explosion suppression device is used, it should comply with the requirements of GB/T 18154.
(3) Explosion suppression system design and application shall comply with the requirements of GB/T 25445.
Four, explosion-proof
1. Definition: Technology to prevent the spread of an explosion after its occurrence, through physical and chemical actions.
2. Purpose: Prevent the spread of flame through pipelines or other conduits
3. Basic Requirements:
(3) Equipment and facilities with a dust explosion hazard, interconnected through pipelines, should ideally be equipped with explosion-proof devices on the pipelines.
(2) Equipment and facilities with a dust explosion hazard that are interconnected through pipelines should be equipped with explosion suppression devices. The shutoff direction should be consistent with the direction of the explosion propagation.
Five. Inertization
For processes such as crushing, grinding, drying of powders, and pneumatic conveying through pipelines within sealed containers, inert gases such as nitrogen, carbon dioxide, halogenated hydrocarbons, argon, helium, and steam, as well as inert dusts like fire retardant powder, chemical dry powder, and mineral rock powder are introduced. This is to dilute combustible components and reduce the oxygen content in the environment.
Explosion-proof electrical retrofitting for hazardous areas and on-site explosion-proof construction consulting services - Shenzhen Zhongnuo Testing Technology Co., Ltd.