Corrosion in equipment, particularly in the oil and gas sector, poses significant challenges, especially when mercury and its compounds are involved. This paper introduces a nano-composite coating to prevent atmospheric and under-insulation corrosion at a mercury removal unit (MRU). The coating, composed of 30% water-based acrylic resin and 70% nano-composite material, features nanometer-scale tunnels that eliminate microscopic air gaps and enhance hydrophobic properties, preventing moisture ingress. The effectiveness of the coating was evaluated using the GM9540P environmental corrosion test. Results showed that while the uncoated surface exhibited complete corrosion, the coated section remained corrosion-free after multiple test cycles. This study highlights the dual benefits of nano-coating: providing both insulation and corrosion resistance, reducing maintenance costs, and improving long-term equipment reliability.