Explosion-proof national standards (GB3836)

Date：2012-12-22

Explosion-proof national standards (GB3836) analysis

1.Division for the dangerous sites

According to place exists in the physical state of matter, for the dangerous sites will be divided into explosive gas and combustible dust environment.  

Dangerous substances exist in the place of the length of time, will be under the two different types of state of dangerous sites is divided into three zones, Namely: to the explosive gas environment, 0 zone, 1 zone and 2 zone; For combustible dust environment, for 20 zone, 21 zone and 22 zone.

In view of the explosive gas environment, GB 3836.14 — 2000 Specified in the standard:

0 zone: the explosive gas environment is a continuously or for long time.

1 zone: when in normal operation, possible explosive gas environment.

2 zone: during normal operation, no possible explosive gas environment, if there is occasionally happen and the existence of places is only a short time.

Here, "normal operation" refers to the normal driving, running, parking, flammable material products of loading and unloading, airtight container, lid opening and closing of the valve, discharge valve, and all the factory equipment in its design parameters to work within the scope of the state.

2.Explosion-proof marks parsing

Explosion-proof electrical equipment according to standard GB 3836 requirements, explosion-proof electrical equipment of explosion-proof signs include:

Ex Type + Equipment category+ Gas group+ Temperature classes

For example, NTAR - 3000 products, NTAR - 3000 explosion-proof marks: Exd Ⅱ BT5, do the following details:

(1)Explosion-proof type

Electrical equipments used in explosive gas environment is divided into:

Class I: the coal mine electrical equipment;

Class II: using electrical equipment factory

Class II flameproof "d" and "I" intrinsically safe electrical equipment is divided into type IIA, IIB, IIC.  

（NTAR-3000 Belong to class II electric equipment, can use in other explosive gas environment besides coal mine.）

(3)Gas group

Explosive gas mixture detonating capability, marks its explosion hazard degree of high and low, the greater the explosive power of explosive mixture, the higher risk. Explosive mixture detonating capacity available maximum test security said on the sidelines. At the same time, the explosive gas and liquid to the difficulty of the steam, the mist was lit also marks its explosion hazard degree of discretion, it USES the minimum ignition current than said. Class II flameproof electrical equipment or intrinsically safe electrical equipment, according to the applicable to the biggest test of explosive gas mixture security clearance or minimum ignition current ratio, further divided into type IIA, IIB, IIC class. Shown in the following table.

（NTAR-3000 Can be used in explosive gas environment with IIB class）

(4)Temperature classes

The ignition temperature of explosive gas mixture is the temperature limit value can be lit.

Electrical equipment according to its maximum surface temperature can be divided into T1 ~ T6 group, makes the corresponding T1 ~ T6 group of electrical equipment of the highest surface temperature cannot exceed the corresponding temperature classes permitted. Temperature classes, the equipment surface temperature and the relationship between the ignition temperature of flammable gas or vapor shown in the table below:

This is related to gas ignited temperature electrical equipment (assuming the environment temperature of 40 ℃) of the highest surface temperature and light energy has nothing to do with the fire temperature.