5 common errors in selecting explosion-proof reducers, and analysis of common mistakes in checking explosion-proof levels

Many enterprises only focus on basic parameters such as price, torque, and transmission ratio in the procurement and selection process of explosion-proof reducers, ignoring the special characteristics of explosion-proof working conditions. Often, problems such as "false matching of explosion-proof grades, mixing of ordinary reducers, and ignoring temperature groups" occur. Mild cases may result in failed security checks, equipment damage in the short term, and severe cases may lead to major safety accidents such as combustion and explosion. Based on years of experience in industry security checks and equipment debugging, we have identified the top 5 most common selection errors in the industry. At the same time, we have dismantled high-frequency error prone points for explosion-proof level verification to help companies avoid safety and cost risks.

1、 Inventory of 5 fatal selection errors

1. Confuse explosion-proof level and IP protection level

This is the most common mistake that beginners make. Many people believe that gearboxes with high protection levels of IP65 and IP67 are explosion-proof devices, but in fact, the two are completely unrelated. The IP protection level is only used for dust and water prevention, targeting external moisture and solid impurities; The explosion-proof level is specifically designed for flammable and explosive media, controlling sparks and high-temperature ignition sources. High IP grade ordinary reducers still cannot withstand explosions caused by flammable gases and cannot replace explosion-proof reducers.

2. Blindly downgrade selection and pursue low cost

Some companies choose low-grade explosion-proof equipment in high-risk areas to reduce costs, such as the increased safety Ex e reducer that is only suitable for Zone 2 in the periodic combustible gas environment of Zone 1; Hydrogen IIC high-risk environment, purchase IIB level ordinary explosion-proof equipment. This type of equipment can operate normally in the short term, but once the medium concentration exceeds the standard or the equipment is overloaded and heats up, it is highly likely to trigger an explosion, which is also a violation that the safety supervision department focuses on investigating.

3. Ignore explosion-proof protection for non electrical parts

Most technicians only focus on the explosion-proof properties of the supporting motor and ignore the risks of the gearbox itself. In fact, high-speed friction of gearbox gears, overheating of bearings, and failure of shaft end seals can also generate high temperatures and sparks. In environments with dust and high concentrations of flammable gases, only the motor is explosion-proof and the gearbox is not explosion-proof, and the entire transmission system still has safety vulnerabilities.

4. Unreasonable setting of safety factor

Explosion proof working conditions strictly prohibit equipment from operating at full load or overload. Part of the procurement follows the safety factor of ordinary reducers, with only 1.2 times the safety factor set for high-risk impact conditions. The equipment operates under long-term overload, causing the surface temperature to continue to rise, breaking through the ignition threshold of flammable and explosive media, and burying potential explosion hazards.

5. Ignoring the matching temperature group of the environment temperature

The temperature group is the core of explosion-proof rating, but it is the most easily overlooked. T1-T6 correspond to different maximum surface temperatures. If the temperature group of the equipment is lower than the medium requirements, such as using T3 level equipment to handle low ignition temperature solvents under high temperature conditions, it will directly cause spontaneous combustion of the medium, which is also the main reason for the high incidence of accidents in the pharmaceutical and fine chemical industries.