Definition of a fusible internal floating disk

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This post was last edited by battery1 on 2022-3-18 at 14:07. GB50160 sets out requirements for fire protection measures in tanks with fusible internal floating roofs, but it does not clarify the concept of \"fusible\" nor the methods for classifying such materials, which makes implementation somewhat ambiguous. Currently, there are mainly four types of materials used for inner floating discs: 1. Carbon steel (mostly phased out); 2. Aluminum alloy (widely used); 3. Stainless steel (mainly SS304); 4. Composite materials (with resin and fiberglass being the main components). In my opinion, the term “easy to melt” should be applied only within the operating conditions of inner floating discs, and such materials must meet two conditions: 1) For example, if the medium inside the tank is gasoline and the flame temperature is 800–1000°C, the melting point of aluminum alloy is around 660°C, while that of resins is generally below 200°C; therefore, these two materials should be considered “easy to melt”“ ； 2). Again, for stainless steel, if the wall thickness is too thin, severe softening and deformation occur within 2.5 hours during combustion tests in a gasoline medium; it should also be considered \"easy to melt\"“ ； The purpose of determining these two points is to find out whether, in the event that the medium beneath the floating disc catches fire, it can continue to provide protection within 2.5 hours. The above are my personal opinions; I welcome fellow netizens to discuss them together. Thank you~