The new version of the GB/T3836 series standard has been officially implemented on May 1, 2022. The difference between new and old standards is a concern for many corporate customers, and explosion-proof signs serve as the "ID card" of products,It can enable users and installation personnel to quickly understand the safety of this explosion-proof productExplosion proof typeCorresponding gas/dust and temperature groups. So as to avoid installing gas explosion-proof products in dust areas, and installing "n" type products in explosion-proof areas in Zone 1. Ensure that explosion-proof products match hazardous areas in terms of selection.
Based on the introduction of the new GB/T 3836-2021 standard, Zhongnuo Testing summarizes the content and significance of the explosion-proof signs for Ex equipment used in explosive gas environments. In the future, we will continue to share the use of Ex equipment in places with combustible dustExplosion proof signsKnowledge.
The explosion-proof signs for Ex equipment used in explosive gas environments should include:
1、 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.
2、 Explosion proof protection type,The explosion-proof protection measures taken by the equipment, the type of explosion-proof protection, and the corresponding code relationshipSee the table below.
Note: In addition to the 8 explosion-proof protection types listed above, Ex equipment can also be used in explosive gas environments with light radiation explosion-proof types and explosion-proof special types. Due to the scarcity of such products, we will not elaborate on them here.
3、 Explosive gas category
1Class I: Coal mine gas
2Class IIA, IIB, and IIC: explosive gases other than coal mine gas environments, as shown in the table below.
4、 Temperature group,The temperature limit at which the ignition temperature of an explosive gas mixture can be ignited.
Electrical equipment according to itsMaximum surface temperatureDivide into T1~T6 groups, so that the maximum surface temperature of the electrical equipment in the corresponding T1~T6 groups cannot exceed the allowable value of the corresponding temperature group. The relationship between temperature groups, equipment surface temperature, and ignition temperature of explosive gases or vapors is shown in the table below.
Remarks:
1The explosion-proof label of Class I Ex equipment does not need to indicate the temperature group.
2Under the same conditions, T6 equipment can be used in T1~T5 locations, while T5 equipment can be used in T1~T4 locations,And so on.
3For maximum surface temperature exceeding 450 ° CofClass II Ex equipment should be marked with the highest surface temperature in Celsius, for example, 600 ° C.
4Class II Ex equipment used for special gases does not need to indicate the corresponding temperature group or maximum surface temperature.
5Ex components do not need to be labeled with temperature group or maximum surface temperature (Celsius temperature).
5、 Applicable Equipment Protection Level (EPL)
The relationship between different equipment protection levels and explosion-proof areas is shown in the table below.
Remarks:
1Ma/Mb is the protection level of Ex equipment for coal mine gas environment; Ga/GB/Gc is the Ex equipment protection level for explosive gas environments other than coal mine gas environments
2Under the same conditions, Ga>Gb>Gc, Ma>Mb
3The EPL marked on Ex equipment may have stricter restrictions than the EPL commonly used for specific explosion-proof types to illustrate other aspects of the equipment, such as material limitations. For example, when the aluminum content of the equipment exceeds the allowable value in GB/T 3836.1.8.3, iaofThe EPL level of Ex devices is Gb, such as Ex ia II C T4 Gb.
ExThe signs should be marked in the order given in the above columns, with small intervals between them.
Example of explosion-proof signs:
Ex ib I Mb
ExElectrical equipment marking for explosion-proof gas environments
Ib: The protection type is intrinsically safe
ICoal mine gas environment
MbEquipment protection level, can be used in Zone 1
Ex db eb II C T6 Gb
ExElectrical equipment marking for explosion-proof gas environments
DB: The protection type is explosion-proof type
EbThe protection type is increased safety type
IICIIC gas andsteamenvironment
T6The temperature level is T6, and the maximum surface temperature of the equipment does not exceed 85 ° C
GbEquipment protection level, can be used in Zone 1/Zone 2
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