Exhaust Fan Explosion-Proof Certificate Acquisition Process, Shenzhen ZhongNuo Inspection, Application Cycle

Shenzhen ZhongNuo Testing Technology Co., Ltd. is based in South China and specializes in explosion-proof certification and coal safety certification application consulting services, offering a one-stop explosion-proof technology consulting service.
Division of Explosion-Proof Zones in Combustible Dust Environments -- Shenzhen ZhongNuo Inspection Technology Co., Ltd.
In explosion-proof certification, hazardous areas are divided into explosive gas environments and combustible dust environments based on the different states of substances present in the location. Based on the duration of presence of hazardous substances in the location, these two types of hazardous areas with different states are further divided into three zones.
For combustible dust environments, it applies to Zones 20, 21, and 22.
Areas in Zone 20 where flammable dust environments occur continuously or persist for extended periods, typically exceeding 1000 hours per year.
Zone 21 - Areas where potentially explosive dust atmospheres may occur during normal operation, typically 10-1000h/year
Zone 22 - In normal operation, it is impossible to have an environment with combustible dust or a place that occasionally exists for a short period of time, generally below 10h/y.

Classification of Explosion-Proof Certification -- Shenzhen ZhongNuo Testing Technology Co., Ltd.
Electrical equipment for explosive gas environments:
Explosion-proof type d
(2) Increased safety type e
(3) Intrinsically Safe i
Positive Pressure Type P
(5) Immersion Type
(6) Sand-filled type q
Sealant Type m
(N) Type
2. Electrical Equipment for Combustible Dust Environments
Dust-Proof Ignition-Resistant Enclosure
(2) Positive Pressure Type
(3) Intrinsically Safe
(4) Cast-in-place
3. Explosion-proof type S
4. Composite: A combination of two or more of the above explosion-proof types

What are the requirements for a company to apply for explosion-proof certification -- Shenzhen ZN Testing Technology Co., Ltd.
For enterprises, applying for a domestic explosion-proof certificate imposes no special requirements on the company (except for the explosion-proof 3C certification).
Primarily, it's about checking if the product meets the explosion-proof standards and whether the required certification documents can be provided.
If the product falls under the explosion-proof 3C certification category, the applicant company must have a production factory (OEM/ODM is also acceptable).
Because the explosion-proof 3C certification is a certification model that incorporates both type testing and factory inspection.
In addition to product testing, an annual audit of the manufacturing facility is required.

What standards are used for explosion-proof certification? What are the technical requirements?
An explosion-proof type is a type of explosion-proof design for electrical equipment.
The housing can withstand explosive mixtures entering the housing through the housing joint surfaces or structural gaps, and explode internally without being damaged.
And cause ignition of an explosive gas atmosphere formed by one, multiple gases or vapors.
Explosion-proof casings must possess both anti-explosion and explosion-proof capabilities. Generally, the casings of explosion-proof products are rather bulky, suitable for products and equipment that are intended for fixed installations and use.
Combustible gas-tight junction width, gap, and roughness are the three key elements of explosion-proof housing design.
Design requirements for the explosion-proof triad differ according to the different explosive gas environments in mining Class I, non-mining Classes IIA, IIB, and IIC.
Please refer to the design standards of GB/T3836.1 and GB/T3836.2 for specifics.
ZheNuo Inspection has long been dedicated to explosion-proof product design, testing, and certification services.
We have a team in the explosion-proof field, well-versed in explosion-proof standard requirements.
We offer explosion-proof housing design, drafting, modification guidance, and certification agency services.
If you have a similar need, feel free to send a private message to Shenzhen Zhongnuo Testing Technology Co., Ltd. at any time!
Explosion-proof Certification Application Consultancy Services - Shenzhen Zhongnuo Testing Technology Co., Ltd.