Boiler manhole is the opening through which maintenance personnel enter the interior of the boiler during inspections or maintenance. It is designed for installing, dismantling, cleaning, and inspecting the internal equipment.HandholeSimilar to manhole structure, consisting of a short pipe section and a blind plate on top. The handhole diameter is generally 150~250mm, ensuring ease of passage for workers' gloved hands and tools. Standardized handholes have nominal diameters of DN150 and DN250. A manhole should be provided when the equipment diameter exceeds 900mm.
