Shenzhen ZhongNuo Inspection Technology Co., Ltd. is based in South China and offers explosion-proof technology consulting services including on-site construction, safety inspections, renovations, project acceptance, and installation. We are well-versed in explosion-proof construction standards, boasting experienced teams and extensive practical experience. We have served major corporations such as PetroChina, LG, Huanlan Environment, BOE, and Sinovac, receiving consistent praise and trust from our clients!
As the world's energy and chemical industries develop, construction in explosive hazardous environments is becoming more widespread, and the prevention and acceptance of such environments are increasingly crucial.
Especially in flammable dust environments, such as plastic factories, feed/food/cereal processing plants, metal polishing workshops, and papermaking/forestry wood flour/fiber dust factories, the number of projects involving explosion-proof installation, design, and retrofitting is also increasing.
Whether it's large-area or localized explosion-proofing, if there are potential hazards in product quality or installation/renovation quality,
Our personnel and property safety are at significant risk, so we must strictly control the quality at every production stage to ensure the reliability and safety of explosion-proof installations and renovations.
Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof construction and modification consulting services. With extensive qualifications and case studies, it's a worthwhile choice!

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 critical. Explosion-proof wiring, installation and use of explosion-proof electrical equipment, dust removal systems, architectural structure layouts, and anti-explosion venting must all comply with the relevant dust explosion-proof standards. Based on a wealth of explosion-proof electrical construction and retrofit cases, Shenzhen ZhongNuo Inspection Technology Co., Ltd. summarizes the following points:
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. Multilayer buildings are best suited for frame structures.
B. Buildings that cannot use frame structures should install explosion relief openings on the walls in accordance with the requirements.
C. If windows or other openings are used as blast relief vents, they must be calculated and ensured to effectively release blast pressure during an explosion.
(4) Evacuation route requirements are as follows:
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 should be installed.
C. Detailed road signs and emergency lighting should be set up for evacuation routes.
2. Process Equipment
(1) If there is a risk of dust explosion in the process equipment within the factory building, it should be located on a higher floor and close to the exterior wall.
(2) Equipment with explosive hazards should be located in outdoor areas outside of buildings.
(3) Equipment or devices that come into direct contact with dust (such as light sources, heating sources, etc.) should have surface temperatures lower than the respective low ignition temperature of the dust.
(4) In areas where combustible dust is present, the transmission mechanisms of the equipment and installations shall comply with the following provisions:
A. The bearings of the process equipment should be dust-proof sealed, and 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-skid protection device should be installed. In the event of sliding friction, the protection device should ensure automatic shutdown.
(5) At the feed point of the process flow, a magnet, an air separator, or a sieve capable of removing impurities mixed in the material should be installed to prevent collisions between the impurities and the equipment.
(6) Effective measures should be taken to prevent sparks from being generated when stainless steel rubs against metal powders such as aluminum, zirconium, or powders containing these metals.
(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, based on the size of the workshop. In emergency situations, the power supply to all motors should be promptly disconnected.
(8) All joints, inspection doors, baffles, and explosion vent covers 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) If the strength of the process equipment is insufficient to withstand the overpressure generated by internal dust explosion under actual operating 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 explosion relief port should be located near potential ignition sources, and it should be as close to the top or upper part of the containment as possible. It must not vent towards flammable and explosive hazard areas to prevent igniting others, and it must not vent towards public areas to avoid injury from explosion relief.
3. Lightning and static electricity protection
Hazardous dust explosion 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 observed:
(1) All metal equipment, enclosures, metal pipelines, brackets, structures, components, etc., generally utilize static-dissipative direct grounding. Where direct grounding is not feasible or prohibited by the process, indirect grounding can be achieved through conductive materials or products.
(2) Containers and piping (belts) used directly for storing electrostatic powder should be made of metal or anti-static materials.
All metal pipe connections should be bonded together.
(4) Operators should take anti-static precautions.
(5) Avoid using a method that involves direct grounding metal conductors or meshes in contact with high-speed flowing powder to dissipate static electricity.

Based on the basic requirements of GB 15577 "Safety Code for Dust Explosion Prevention," in the防爆 construction and modification of explosive dust areas, the following five main explosion-proof measures can be adopted (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.).
Explosion-proof
1. Definition: An explosion suppression technology that, in the event of an explosion within an enclosed space where combustible dust and gaseous oxidizers or air are present, the enclosed space can withstand the high explosion pressure without being destroyed.
2. Objective: By enhancing container wall thickness and improving material, external damage is minimized even in the event of a dust explosion.
3. Basic Requirements:
When producing and handling powders 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 connection parts between various processing 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 impact resistance shall comply with the requirements of GB/T 24626.
2. Bursting Disc
1. Definition: An explosion suppression technology that, when an explosion occurs within the enclosed package, allows the high temperature, high-pressure combustion products, and unburned materials to be vented through pre-set weak points in the package to a safe direction before the explosion pressure reaches the package's limiting strength, thereby preventing the package from being destroyed.
2. Purpose: To reduce explosion losses by installing explosion relief devices.
3. Methods: Two explosion relief methods are available, flameless and flammable.
4. Basic Requirements:
When the strength of the process equipment is insufficient to withstand the overpressure caused by internal dust explosion under actual operating conditions, explosion relief openings should be installed. The relief openings should be directed towards a safe direction, and their dimensions should comply with the requirements of GB/T 15605.
(2) Dust explosion hazard equipment installed indoors should be vented to a safe outdoor direction via pressure relief ducts. The pressure relief ducts 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 be equal to or greater than the strength of the protected equipment container.
(3) Equipment inside the room that cannot vent to the outside through a pressure relief conduit should be fitted with flameless explosion relief caps.
(4) Process equipment with inline piping shall be designed to withstand at least 0.1 MPa of internal overpressure.
Section 3: Explosion Suppression
1. Definition: In the initial stage of an explosion, extinguish the flames and suppress (prevent) the development of dust explosion through physical and chemical actions.
2. Purpose: To preemptively detect and extinguish fires, as well as suppress explosions 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 propagation of an explosion after its occurrence through physical and chemical actions.
2. Purpose: To prevent the spread of flame through pipelines or other passages
3. Basic Requirements:
(3) Equipment and facilities with dust explosion hazards that are interconnected via pipelines should be equipped with explosion-proof devices on the pipelines.
(2) Equipment and facilities with a dust explosion hazard that are interconnected by pipelines should be equipped with explosion-proof devices on the pipelines. The shutoff direction should align with the direction of the explosion propagation.
Five: Inertizing
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 alkanes, 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.

Basic Requirements for Explosion-Proof Electrical Installations in Hazardous Areas (Shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
1. Oil-immersed equipment should be used under conditions of no vibration, no tilt, and fixed installation.
2. When using non-explosion-proof equipment for mechanical transmission as partition walls, the following regulations should be observed:
The room housing electrical equipment should be separated from the explosive hazard area by a solid wall made of non-combustible materials.
(2) Transmission shafts should be sealed at the wall partition using gland packing or equivalent sealing measures.
(3) The exit of the electrical equipment room should lead to an environment free of explosive hazard areas.
(4) When the room where the equipment is installed must be connected to an explosive atmosphere, the explosive atmosphere should be maintained at a positive pressure relative to it.
3. Electrical circuits and equipment in explosive environments, excluding inherently safe circuits, should be equipped with overcurrent, short-circuit, and grounding protection. Overcurrent protection may be omitted for electrical equipment that cannot experience overloads. Motors in explosive environments should be fitted with phase failure protection in addition to the necessary protection as required by current standards. If the automatic shutdown of electrical equipment could pose a greater risk than the ignition hazard, an alarm device should be used in place of the automatic shutdown device.
4. In emergency situations, at suitable locations outside of hazardous areas, one or more measures should be taken to shut off power to the equipment in the hazardous area. Continuous-running equipment should not be included in the emergency shutdown circuit and should be installed on a single circuit to prevent the occurrence of additional hazards.
5. The design of substation, distribution station, and control room shall comply with the following regulations:
Transformer stations, distribution stations (including switchrooms, hereinafter referred to as such), and control rooms should be located outside of explosive atmosphere environments. When they are in positive pressure rooms, they may be situated within zones 1 and 2.
(2) In explosive gas atmospheres where the gas is heavier than air, the equipment floor of electrical and instrumentation in transformer substations, distribution stations, and control rooms located in the additional 2 zone of the explosive danger area should be elevated 0.6 meters above the external ground level.
Explosion-proof electrical renovations and on-site explosion-proof construction consulting services for hazardous areas — Shenzhen Zhongnuo Inspection Technology Co., Ltd.