The new version of GB/T3836 series standards has been officially implemented on May 1, 2022. The difference between the old and new standards is a concern for many corporate clients, and the explosion-proof mark serves as the product's "ID card",It can enable users and installers to quickly understand the explosion-proof productExplosion proof typeCorresponding gas/dust and temperature groups. In order to avoid the installation of gas explosion-proof products in dusty areas, and the installation of "n" type products in the explosion-proof area of Zone 1. Ensure that explosion-proof products are compatible with hazardous areas in terms of selection.

Based on the introduction in the new version of GB/T 3836-2021 standard, Zhongnuo Testing summarizes the content and meaning of the explosion-proof mark for Ex equipment used in combustible dust environments.

The explosion-proof mark for Ex equipment used in combustible dust environments should include:
1、 The symbol Ex indicates that the Ex equipment complies with one or more explosion-proof types listed in Chapter 1 of GB/T 3836.1-2021's specialized standards.
2、 Explosion proof protection type,The explosion-proof protection measures, explosion-proof protection types, and corresponding code relationships adopted by the equipment are shown in the table below.

Note: In addition to the four explosion-proof protection types listed above, there are also radiation explosion-proof types and special explosion-proof types when using Ex equipment for combustible dust. Due to the scarcity of such products, we will not elaborate further here.

3、 Types of combustible dust
III A、IIIB andIIIClass C: Other combustible dust except for coal mine gas environment, as shown in the table below.

Note: Under the same conditions, IIIC＞IIIB＞IIIA

4、 Temperature group refers to the temperature limit at which the ignition temperature of a combustible dust mixture can be ignited.

5、 Applicable Equipment Protection Level (EPL)
The relationship between different equipment protection levels and explosion-proof areas is shown in the table below.

remarks:
1 Da/Db/DC is the Ex equipment protection level for combustible dust environments other than coal mine gas environments
2. Under the same conditions,Da>Db>Dc
3. The Ex logo should be marked in the order given in the above columns, with small intervals between them.

Example of Explosion proof Signs:
Ex tb IIIC T130°C Db
Ex： Electrical equipment labeling for combustible dust environments
tb： The protection type is anti dust ignition shell type
IIICConductive dust environment

T130 ° C: The maximum surface temperature of the equipment shall not exceed 130 ° C
Db： Equipment protection level, can be used in zones 21 and 22

Ex ia IIIB T₂₀₀80°C Da
Ex：Electrical equipment labeling for combustible dust environments
iaThe protection type is intrinsic safety type
IIIB：Non conductive combustible dust environment
T ₂₀₀80°C：The maximum surface temperature of the equipment under the condition of 200mm dust cloud shall not exceed 80 ° C
Da： Equipment protection level, can be used in zones 20, 21, and 22


The content and images of this article are prohibited from being plagiarized or reproduced by any platform or individual! Violators will be held accountable!