In some industrial sectors such as petroleum, chemical, and coal, it is often necessary to produce, process, store, transport, or use flammable gases or liquids. These flammable liquids or gases can leak into the surrounding environment through container or pipeline cracks, sealed joints, operating holes, valves, etc. They mix with the air in the environment, forming an explosive hazardous environment. If there is also an ignition source in the environment, combustion or explosion will occur

In order to prevent explosion and fire hazards, explosion-proof measures should be taken in the above-mentioned places. Explosion proof measures can be divided into two categories in engineering:
1. Primary explosion-proof measures - to avoid explosive hazardous environments in the workplace.
2. Secondary explosion-proof measures - Avoid ignition sources in explosive hazardous environments. National standards and regulations

There are regulations in international standards that require the use of explosion-proof electrical products in explosive hazardous areas to avoid damage to personnel and materials caused by explosions and fires, which is considered a secondary explosion-proof measure.

Explosion proof enclosure type "d" is an explosion-proof type of electrical equipment, whose enclosure can withstand explosive mixtures entering the interior of the enclosure through any joint surface or structural gap without damage, and will not cause ignition of explosive gas environments formed by one or more gases or vapors outside, thereby ensuring environmental safety.

Wolong Group, a globally renowned manufacturer of motors and drive solutions, was founded in 1984. After more than 30 years of innovative development, it has 39 manufacturing plants and 4 research and development centers in China, Vietnam, the United Kingdom, Germany, Austria, Italy, Poland, Serbia, Mexico, and India, with over 15000 employees. The company mainly produces various types of electric motors, generators, control drives, and industrial automation products, providing customers with the best solutions and services in the fields of oil and gas, petrochemicals, electricity, mining, rail transit, construction and building, environmental protection and water treatment, equipment automation, new energy vehicles, etc.