Sealing types for floating roof and semi-floating roof storage tanks

The commonly used standards can be found in Articles 8.9 and 9.5 of GB 50341-2014; further design adjustments are then made based on the specific industry requirements and local regulations.

First of all, I don’t understand what you mean by a semi-suspended roof storage tank; I’m not familiar with this concept. I guess what you mean is a internal floating roof tank. The sealing of floating roof tanks generally adopts a primary seal + secondary seal configuration. Foam soft seals are commonly used for sealing in China. During layout, the safety distance required between floating roof tanks and internal floating roof tanks with steel floating disks is smaller than that between dome tanks or internal floating roof tanks with floating disks made of fusible materials, due to the lower fire risk. In the event of a fire in a dome tank or a floating roof tank with a floating roof made of fusible material, it constitutes a fire that covers the entire surface area of the tank; therefore, when designing the fire-fighting system for such tanks, the amount of foam required is calculated based on the total surface area of the tank. In the case of floating roof tanks and internal floating roof tanks with steel floating decks, fires occur only between the floating deck and the tank wall. It has nothing to do with what type of sealing is used.