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.
Which explosion-proof rating, Ex db eb or Ex db, is higher?
Composite explosion-proof marking indicates that a single explosion-proof type is not sufficient for this product, and at least two or more explosion-proof types must be adopted.
For example, explosion-proof equipment with antennas, the antenna section is typically intrinsically safe, making this device both explosion-proof and intrinsically safe.
Keep up the good work. Generally, the nozzle part belongs to Zone 0 and can only be made as intrinsically safe ia. Other parts 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 that a composite explosion-proof type necessarily has a higher explosion-proof grade than a single explosion-proof type.
The main factor in determining the explosion-proof level of a product is the gas/dust combination, temperature class, and equipment protection level.
Gas Mixtures: II-C > II-B > II-A
Dust Composition: 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!

Explosive-proof certification standard for combustible dust environments:
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 ignition-proof enclosures "t"

Classification of Explosion-proof Certification -- Shenzhen Zhongnuo Inspection Technology Co., Ltd.
Explosion-proof certification is the process of verifying that equipment meets the requirements of explosion-proof standards, type testing, and routine tests, and issuing relevant certificates of compliance. 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.

What are the requirements for a company to apply for explosion-proof certification -- Shenzhen ZhongNuo Testing Technology Co., Ltd.
For businesses, applying for a domestic explosion-proof certificate imposes no special requirements on the company (except for the explosion-proof 3C certification).
Primarily, it's to check 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 inspection.
In addition to product testing, an annual audit of the manufacturing facility is required.
Explosion Proof Certification Application Consulting Service - Shenzhen Zhongnuo Testing Technology Co., Ltd.