Shenzhen Zhongnuo Inspection & Technology Co., Ltd. is based in South China, offering on-site explosion-proof construction, safety inspections, renovations, project acceptance, and explosion-proof installation consulting services. We are well-versed in explosion-proof construction standards, boasting experienced construction teams and a wealth of practical experience. We have served major enterprises such as PetroChina, LG, Huanlan Environment, BOE, and Sinovac Biotech, receiving consistent praise and trust from our clients!
Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof construction services for hazardous areas involving explosive dangers.
1. Explosion-proof site inspection and consultation
2. Explosion-proof engineering site construction and renovation
3. Explosion-proof Construction Acceptance
4. Explosion-proof electrical installation, maintenance, and modification
5. Explosion relief walls, doors, and windows installation
6. Dust Removal Equipment Installation and Retrofitting Construction

Basic Specifications for Explosion-Proof Design in Hazardous Areas (Shared by Shenzhen ZhongNuo Inspection & Testing Technology Co., Ltd.)
1. Initial explosion protection overall design
2. Directly release explosive energy. Around the explosion source, comprehensively utilize anti-explosion and venting techniques. Set anti-explosion walls and windows in the direction of densely populated areas, office zones, and critical equipment. In directions with few people and no critical equipment, set venting walls and windows.
3. Determine the safe distance. Minimize the establishment of office areas, residential areas, and critical equipment zones within the range less than the safe distance unless necessary; if set up, necessary anti-explosion measures should be taken.
4. Conversion of non-blast-resistant buildings to blast-resistant structures. Buildings within the range of less than the safe distance should undergo blast resistance assessment, and those not meeting blast resistance requirements should be reinforced with blast-resistant measures: to prevent building collapse; to prevent the shattering of brittle materials such as bricks, concrete, glass, etc., and the generation of debris.
5. Place explosion-proof shelters in hazardous blast areas.

Installation of electrical wiring in explosive environments shall comply with the following regulations (shared by Shenzhen ZhongNuo Inspection Technology Co., Ltd.)
(1) Electrical wiring should be installed in environments with lower explosion hazards or far from the source of release, and should comply with the following regulations:
1) When the material is heavier than air, electrical wiring should be installed at a higher elevation or directly buried; for overhead installation, cable trays should be used; when using cable trenches, the trench should be filled with sand, and drainage measures should be in place.
2) Electrical wiring should be installed outside the walls of buildings or structures where there is a risk of explosion.
3) In environments with explosive dust, cables should be laid in areas where dust is less likely to accumulate and is easy to remove.
(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 wiring, it is advisable to avoid areas prone to mechanical damage, vibration, corrosion, UV radiation, and heat. If unavoidable, preventive measures should be taken.
(4) The wiring of steel pipes can use insulated single-core or multi-core wires without sheath. When the steel pipe contains three or more wires, the total cross-sectional area of the wires, including the insulation, should not exceed 40% of the steel pipe's cross-sectional area. The steel pipes should be of the galvanized lock-welded type for low-pressure fluid conveyance. The threaded section of the steel pipe connection should be coated with lead oil or phosphatizing paste. In areas where condensation water may form, a sealed joint for draining condensation water should be installed on the pipeline.
(5) Electrical wiring for piping in explosive gas environments should be properly insulated and sealed, and should comply with the following regulations:
1) During normal operation, the 450mm range around all ignition source enclosures should be sealed off.
2) Steel pipes with a diameter of 50mm or more should be isolated and sealed within 450mm from the incoming junction box.
3) Isolation and sealing should be conducted 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 be filled with a fibrous layer as the bottom or separator layer, with the effective thickness of the filling not less than the inner diameter of the steel pipe, and not less than 16mm.
4) Connection components for isolation sealing should not be used for wiring connections or branching.
(6) Intermediate joints are strictly prohibited in cable lines within Zone 1, and intermediate joints should not be present in Zones 2, 20, and 21.
(7) When connecting the ends of cables or wires, if the internal wires are stranded, the ends should be connected with a crimped terminal or a splicing sleeve. 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 pole tower. In special circumstances, after taking effective measures, the distance may be appropriately reduced.

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 inclination, and fixed installation.
2. When using non-explosion-proof equipment for mechanical transmission as partition walls, the following regulations should be followed:
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 with gland packing or equivalent sealing measures at the wall partition.
(3) The exit of the electrical equipment room should lead to an environment free of explosive hazard areas.
(4) When the room housing the equipment must be connected to an explosive atmosphere, the explosive atmosphere should be maintained at a positive pressure relative to the room.
3. Electrical circuits and equipment in explosive environments, excluding inherently safe circuits, should be equipped with overload, short-circuit, and grounding protection. Electrical equipment that cannot experience overload does not require overload protection. Motors in explosive environments, in addition to being installed with necessary protections as required by current standards, should also be equipped with phase failure protection. 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, appropriate measures should be taken at a suitable location outside the hazardous area to disconnect the power to the equipment in the hazardous area. Continuous operating equipment should not be included in the emergency shutdown circuit and should be installed on a separate circuit to prevent the occurrence of additional hazards.
5. The design of transformer stations, distribution stations, and control rooms shall comply with the following regulations:
Transformer stations, distribution stations (including distribution rooms, etc.), and control rooms should be located outside of explosive atmosphere environments. When they are in positive pressure rooms, they can be arranged in zones 1 and 2.
(2) For explosive gas atmospheres where the gas is heavier than air, the equipment floor of the substation, distribution station, and control room located in the additional zone 2 of the explosion hazard area should be elevated 0.6 meters above the exterior ground level.
Explosion-proof electrical改造 and on-site explosion-proof construction consulting services for hazardous areas — Shenzhen Zhongnuo Testing Technology Co., Ltd.