There are many explosion-proof products on the market, but many users are not specialized in explosion-proof products, in the face of a variety of explosion-proof products, often fall into the use of misunderstanding, one of the most important misunderstanding is the definition of explosion-proof and protection is what?

I believe we all know that a lot of fire products will indicate the product in the manual “ Protection class IP65” “ Explosion-proof standard ExdⅡCT6” Many specific places have corresponding requirements for the protection level and explosion-proof of products when installing fire protection products. Then fire products “ Protection ” And “ Explosion-proof ” What is the standard definition? Today, Deli Innovation will explain this knowledge to you.

Class of protection

IP is the abbreviation of Ingress Protection, IP level is for the electrical equipment shell to foreign body intrusion protection level, such as: explosion-proof appliances, waterproof and dustproof appliances, from the International Electrotechnical Commission standard IEC60529.

The protection level is mostly expressed by IP followed by two numbers, and the number is used to clarify the level of protection.

The first number indicates the range of the device's resistance to fine dust, or the degree to which people are protected from harm in a sealed environment. Represents the level to prevent the entry of solid foreign bodies, the highest level is 6;

The second number indicates how waterproof the device is. Represents the level of water protection, the highest level is 8.

Dustproof class IPXX(the first X indicates)

0: No protection

1: Prevent the invasion of large solids

2: Prevent the invasion of medium sized solids

3: Prevent small solids from entering

4: Prevent solids larger than 1mm from entering

5: Prevent harmful dust accumulation

6: Completely prevent dust from entering

Waterproof rating IPXX(second X indicates)

0: No protection

1: Water drops into the shell has no effect

2: When the shell is tilted to 15 degrees, the water drop into the shell has no effect

3: Water or rain from 60 degrees corner to the shell has no effect

4: Liquid poured into the shell from any direction has no harmful effect

5: Rinse with water without any harm

6: Can be used in the cabin environment

7: Can be soaked in a short time (1m)

8: Immersed in water for a long time under a certain pressure

1. Explosion-proof type

According to the explosion-proof measures taken, the explosion-proof electrical equipment can be divided into flameproof type, increased safety type, intrinsically safe type, positive pressure type, oil immersed type, sand filled type, pouring type, n type, special type, dust explosion-proof type, etc. Their identification is shown in the following table

Noun interpretation

Flameproof electrical equipment (d) means an electrical equipment that encloses a component that can ignite an explosive mixture in a housing that can withstand the explosive pressure of the internal explosive mixture and prevent the detonation of the surrounding explosive mixture.

Increased safety electrical equipment (e) : Electrical equipment which, under normal operating conditions, does not produce sparks or hazardous temperatures that ignite explosive mixtures and which is structurally enhanced by measures to improve its safety in order to avoid ignition under normal and prescribed overload conditions.

Intrinsically safe electrical equipment (i) : Electrical equipment that cannot ignite explosive mixtures by sparks or thermal effects during normal operation or under standard test conditions.

Non-spark electrical equipment (n) : Electrical equipment that does not produce an arc or spark under normal operating conditions, does not produce a high temperature surface or hot point that can ignite the surrounding explosive mixture, and generally does not have an ignition failure.

Special type of explosion-proof (s) : When electrical equipment or components adopt explosion-proof types not included in GB3836, provisional provisions shall be formulated by the competent authorities. It shall be sent to the Ministry of Labor and Human Resources for the record, and shall be disposed of according to special electrical equipment type s after inspection by the designated appraisal unit.

2. Equipment category

Electrical equipment for explosive gas environment is divided into:

Class I: Electrical equipment used in coal mines;

Class II: Electrical equipment for explosive gas environments other than coal mines;

Class II flameproof type “ d” And intrinsically safe “ i” Electrical equipment is divided into IIA, IIB, and IIC categories;

Electrical equipment for combustible dust environment is divided into:

Type A dust tight equipment; B type dust tight equipment; Type A dustproof equipment; Type B dust proof equipment.

3. Gas group

The detonation ability of explosive gas mixture marks the level of its explosion danger, and the greater the detonation ability of explosive mixture, the higher the risk. The detonation capacity of an explosive mixture can be expressed by the maximum test safety gap. At the same time, the difficulty of explosive gas, liquid vapor and mist being ignited also marks the level of its explosion risk, which is expressed by the minimum ignition current ratio. Class II flameproof electrical equipment or intrinsically safe electrical equipment is further classified into classes IIA, IIB and IIC according to its maximum test safety clearance or minimum ignition current ratio for explosive gas mixtures. As shown in the following table:

4. Temperature group

The ignition temperature of an explosive gas mixture is the limit temperature at which it can be ignited.

Electrical equipment is divided into T1-T6 groups according to its maximum surface temperature, so that the maximum surface temperature of the corresponding T1-T6 group of electrical equipment cannot exceed the allowable value of the corresponding temperature group. The relationship between temperature groups, equipment surface temperatures and ignition temperatures of combustible gases or vapors is shown in the table below.

For example, the explosion-proof mark of a product is ExdIIBT4, which means that the product type is flameproof type, which is Class IIB (Class) used in Class II places, and the ignition temperature of explosive gases is T4 group.