If an internal floating methanol tank is equipped with a nitrogen seal, is an internal floating disk still necessary?

I think one is enough; are there any other safety considerations if both are installed? Listen to what other experts have to say

A nitrogen seal is required, as well as an internal floating roof; this not only enhances safety but, more importantly, helps to effectively reduce methanol vapor loss

It is recommended to eliminate the nitrogen seal and lead the vent valve outside the tank, adding a water seal on the tank roof, which will save energy.

Internal floating roofs are not only safe but also reduce liquid evaporation; nitrogen sealing is primarily aimed at ensuring safety, and it is less effective in reducing liquid evaporation compared to floating roofs

Methanol: Its chemical formula is CH3OH. It was first obtained through the dry distillation of wood, which is why it is also called wood alcohol or wood spirit. Methanol is a colorless, volatile liquid with an alcoholic odor. Melting point: -93.9°C, boiling point: 64.7°C, density: 0.7914 g/cm3 (20°C); soluble in water and many organic solvents. Methanol is toxic; ingesting 5–10 milliliters can cause blindness, while consuming large amounts can lead to death. Under the prohibition, methanol was mixed into alcohol to create denatured alcohol, making it unfit for consumption. Methanol is flammable, and its vapors can form explosive mixtures with air. When methanol burns completely, it produces carbon dioxide and water vapor, releasing heat in the process. Volatile liquids must be equipped with internal floating disks to prevent evaporation and reduce losses.

How can it still be called an internal floating roof tank without an internal floating disk? How is it possible to remove the internal floating disk?

Nitrogen blanketing is used to reduce volatilization, while the choice between an internal floating roof and a floating roof (without an internal floating disk) should be made in accordance with the relevant standards. Methanol belongs to Category A. According to the \"Design Code for Storage Areas in Petrochemical Storage and Transportation Systems\", for liquids of Categories A and B whose saturated vapor pressure at storage temperature is below atmospheric pressure, floating roof tanks or internal floating roof tanks should be used, and the following requirements must be met: a Floating roof tanks should employ steel floating deck types and must be equipped with a double-sealing mechanism ； For b internal floating roof tanks, metal floating tank-type floating roofs should be used.

For nitrogen sealing, safety and the prevention of contamination of the storage medium are key considerations, which means an internal floating disk should be used.

Use an internal floating disk. Nitrogen sealing is just a supplementary measure.

With increasing demands for energy conservation and environmental protection, the internal floating disk + nitrogen seal approach is becoming a trend. Some projects have already been implemented.

This is the first time I’ve heard of it. Could you please explain it in more detail or provide a photo.............