1. Explosion proof type GB/T 3836.2-2021- Explosive atmospheres - Part 2: Equipment protected by explosion-proof enclosure "d"

Explosion proof mark: Ex d

Explosion proof principle: The explosion-proof type is to enclose all components of the equipment that may ignite explosive gas mixtures in a shell. The shell can withstand the explosive mixture that penetrates into the interior of the shell through any joint surface or structural gap without damage, and will not cause ignition of the explosive environment formed by one or more gases or vapors outside (see GB/T3836.2 standard). Put all components that may generate sparks, arcs, and dangerous temperatures into a flameproof enclosure, which separates the internal space of the equipment from the surrounding environment. There are gaps in the explosion-proof shell, and due to the breathing and gas permeation of electrical equipment, there may be explosive gas mixtures inside. When an explosion occurs, the shell can withstand the generated explosion pressure without damage. At the same time, the gaps in the shell structure can cool the flame, reduce the flame propagation speed, or terminate the acceleration chain, so that the flame or dangerous flame products cannot penetrate the explosion-proof gap and ignite the external explosive environment, thereby achieving the purpose of explosion-proof.

2. Increased safety explosion-proof GB/T 3836.3-2021- Explosive atmospheres - Part 3: Equipment protected by increased safety type "e"

Explosion proof mark: Ex e

Explosion proof principle: The increased safety explosion-proof type is an explosion-proof type that takes additional measures to improve the safety of electrical equipment that does not generate arcs or sparks under normal operating conditions, and prevents the possibility of dangerous temperatures, arcs, and sparks in its internal and external components. It does not include equipment that generates sparks or arcs under normal operating conditions (see GB/T 3836.3 standard). On the structure of electrical equipment that does not generate sparks, arcs, and dangerous temperatures during normal operation, measures are taken to reduce or control the operating temperature, ensure the reliability of electrical connections, increase insulation effect, and improve the protection level of the casing to reduce the possibility of contamination caused by dirt and moisture entering, thereby reducing the possibility of ignition faults and improving the safety and reliability of equipment under normal operation and specified fault conditions (such as motor rotor blockage).

3. Intrinsic safety explosion-proof GB/T 3836.4-2021- Explosive atmospheres - Part 4: Equipment protected by intrinsic safety type "i"

Explosion proof mark: Ex i

Explosion proof principle: The intrinsic safety explosion-proof type is an intrinsic safety circuit in which all circuits inside the equipment are generated under standard specified conditions (including normal operation and specified fault conditions), and any electric sparks or thermal effects cannot ignite the specified explosive gas environment. Intrinsically safe type starts with limiting the energy in the circuit, reducing the potential spark energy to below the specified ignition energy of the gas mixture through reliable control of circuit parameters, and limiting the surface heating temperature of wires and components to below the specified ignition temperature of the gas mixture.

4. Positive pressure explosion-proof GB/T 3836.5-2021 Explosive atmospheres Part 5 Equipment protected by positive pressure enclosures

Explosion proof mark: Ex p

Explosion proof principle: Fresh air or inert gas at a certain pressure is introduced into the casing of the equipment to prevent surrounding flammable gases from entering the interior of the casing, thereby preventing point source ignition from coming into contact with explosive gases and achieving the purpose of preventing explosions.

5. Oil immersed explosion-proof GB/T 3836.6-2017Explosive environmentPart 6: Oil immersed type "o"

Explosion proof mark: Ex o

Explosion proof principle: Oil immersed explosion-proof type involves immersing the entire equipment or its components in oil (protective liquid) to prevent ignition of explosive gas environments above the oil level or outside the casing (see GB/T 3836.6 standard). This is an old explosion-proof technology method mainly used for switchgear. The formed arc and spark are immersed in oil.

6. Explosion proof sand filling GB/T 3836.7-2017Explosive environmentPart 7: Sand mold filling "q"

Explosion proof mark: Ex q

Explosion proof principle: The sand filled explosion-proof type is an electrical equipment protection type that fills the shell with sand particles or other specified powder materials, so that under specified usage conditions, the arc or high temperature generated inside the shell cannot ignite the surrounding explosive gas environment.

7 Type N Explosion proof GB/T 3836.8-2021- Explosive Atmosphere Part 8: Equipment Protected by Type N

Explosion proof mark: Ex n

Explosion proof principle: n-type is a form of explosion-proof electrical equipment. This type of electrical equipment cannot ignite the surrounding explosive environment under normal operation and certain conditions specified in this standard (only referring to the light source failure condition of the lamp).

8. Sealed Explosion proof GB/T 3836.9-2021- Explosive Atmosphere Part 9: Equipment Protected by Sealed Type "m"

Explosion proof mark: Ex m

Explosion proof principle: Seal the parts of the equipment that may generate sparks or high temperatures in a sealing agent (resin) to prevent them from igniting the surrounding explosive mixture