Shenzhen Zhongnuo Testing Technology Co., Ltd. is based in South China and specializes in explosion-proof certification and coal mine safety certification application consulting services, offering one-stop explosion-proof technology consulting services.
Which explosion-proof grade, Ex db eb or Ex db, is higher?
The composite explosion-proof marking indicates that a single explosion-proof type is insufficient for this product, and at least two or more explosion-proof types must be used.
For example, explosion-proof equipment with antennas, the antenna section is usually intrinsically safe treated; this equipment is both explosion-proof and intrinsically safe.
Keep it up! Generally, the nozzle part falls under Zone 0, which can only be made as intrinsically safe ia. Other sections can be made as Zone 1, suitable for intrinsically safe ib or explosion-proof types.
Composite explosion-proof products do not mean that the product must meet all the requirements of different explosion-proof types simultaneously.
It's not necessarily true that the explosion-proof rating of a composite explosion-proof type is always higher than that of a single explosion-proof type.
The main factor to consider when assessing a product's explosion-proof rating is the gas/dust combination, temperature class, and equipment protection level.
Gas Mixture: ⅡC > ⅡB > ⅡA
Dust Combination: ⅢC > ⅢB > ⅢA
Temperature Grades: T6 > T5 > T4 > T3 > T2 > T1
Equipment Protection Combination: Ga > Gb > Gc, Da > Db > Dc
For more details, please contact Shenzhen Zhongnuo Testing Technology Co., Ltd. directly!

Flammable Dust Environment Explosion Proof Certification Standard:
GB/T 3836.1-2021 Explosive Atmospheres Part 1: Equipment General Requirements
GB/T 3836.4-2021 Explosive Atmospheres Part 4: Equipment protected by intrinsic safety "i"
GB/T 3836.5-2021 Explosive Atmospheres, Part 5: Equipment protected by positive pressure enclosures "p"
GB/T 3836.9-2021 Explosive Atmospheres Part 9: Equipment protected by "m" type enclosures
GB/T 3836.31-2021 Explosive Atmospheres, Part 31: Equipment protected by dust-protection enclosures "t"

Explosion-proof Certification Categories -- Shenzhen ZhongNuo Testing Technology Co., Ltd.
Blastproof certification is the process of verifying that equipment meets the requirements of blastproof standards, type testing, and routine tests, and issuing the relevant qualification certificates. Certificates can be issued for Ex equipment or Ex components.
Different regions have varying certification standards and systems for explosion-proof electrical products. Currently, international explosion-proof certifications include domestic explosion-proof certification, ATEX certification, IECEx certification, and North American explosion-proof certification, among others.

What are the requirements for enterprises to apply for explosion-proof certification? -- Shenzhen Zhongnuo Testing Technology Co., Ltd.
For enterprises, there are no special requirements for applying for domestic explosion-proof certificates (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 must have a production factory (OEM/ODM is also acceptable).
Because the explosion-proof 3C certification is a certification model that combines type testing with factory audit.
In addition to product testing, an annual audit of the manufacturing facility is required.
Explosion Proof Certification Application Consulting Services - Shenzhen Zhongnuo Testing Technology Co., Ltd.