Hot work on internal floating roof storage tanks – seeking advice
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Work was carried out at the bottom of the internal floating roof tank; the process procedures were followed properly, blind flanges were installed at the inlets and outlets, and the sections that needed to be cut off were indeed cut. I would appreciate some advice: does an internal floating roof need to be removed? Could the presence of an internal floating roof lead to the formation of explosive gas mixtures in certain areas within the tank?
After the replacement is approved, open the manhole to enter and conduct inspections; if welding is to be carried out on the outside of the tank, nitrogen shall be filled inside the tank for protection.
There is no need to remove the internal floating roof; after thorough isolation, forced ventilation is required, and flammable gases must be analyzed before performing any welding work
Is it possible to perform hot work inside a tank without removing the internal floating roof?
Is it possible to perform hot work inside a tank without removing the internal floating roof?
The spaces above and below the floating roof must both pass inspection; all connected pipes shall be subjected to isolation and purging tests, and forced ventilation shall be provided after the manholes are opened.
The internal floating roof must be purged with nitrogen on both the upper and lower sides, and inspections on both sides must show satisfactory results before work can begin. However, it is necessary to consider whether working with fire could damage the internal floating roof.
When performing welding work inside a tank, it is also necessary to consider what material is contained within the tank and whether it adheres to the tank walls; as well as whether it volatilizes under high temperatures. Nowadays, many tanks experience flash explosions after such welding work. As for the internal floating roof, there is no need to remove it, and forced ventilation can be used at the entrance
The media stored in internal floating roof tanks are usually volatile; once the media inside the tank is depleted, natural ventilation is achieved by opening the manhole, followed by forced ventilation； Before carrying out hot work, strict procedures must be followed, and blind plates must be installed to isolate it from other equipment and pipelines ； The gas content in the sampling and analysis container meets the operational requirements; inspections are also required inside the tank and above the floating roof ； Issue a work permit for entry into confined spaces within containers ； Work is to be carried out inside the tank, with a dedicated person required to monitor from outside ； When performing hot work inside a tank, pay attention to the sealing device at the junction between the floating roof and the tank wall to prevent damage caused by high temperatures ； Wait, safety first