Shenhai Explosion-Proof
A key aspect to consider for metal materials in explosion-proof electrical equipment is their propensity to ignite explosive gas-air mixtures through mechanical sparks. Research has indicated that the composition of these metals plays a substantial role in their ignition potential. To prevent the occurrence of mechanical spark ignition in metal enclosures, specific elemental limitations are mandated. The standards for explosive environments – General Equipment Requirements – specify the following:
Class I
In producing RPL level MA or Mb explosion-proof electrical equipment, the composition of aluminum, magnesium, titanium, and zirconium in the enclosure materials must not exceed 15% by mass, and the combined mass percentage of titanium, magnesium, and zirconium must not surpass 7.5%.
Class II
For Class II explosion-proof electrical equipment production, the total mass percentage of critical elements in enclosure materials varies based on the protection level: For EPLGa equipment, the total content of aluminum, magnesium, titanium, and zirconium must not exceed 10%, with magnesium, titanium, and zirconium not exceeding 7.5% in total; For EPLGb equipment, the aggregate content of magnesium and titanium must not exceed 7.5%; In the case of EPLGc equipment, apart from fans, fan covers, and ventilation hole baffles meeting EPLGb standards, there are no additional specific requirements.
Class III
In manufacturing Class III explosion-proof electrical devices, the required total mass percentage of pertinent elements in the enclosure materials also varies with the protection level: For EPLDa devices, magnesium and titanium content should not exceed 7.5%; For EPLDb devices, the same limitation applies; For EPLDc devices, apart from fans, fan covers, and ventilation hole baffles adhering to EPLDb criteria, there are no further special requirements.