Which has a greater annual material loss volume, the large breathing or the small breathing of internal floating roof storage tanks?

Determined based on operational conditions. If it runs frequently, large breaths result in greater material loss than small breaths; otherwise, the opposite is true.

**Appendix A of the \"Guidelines for Energy-Efficient Design of Oil Storage Tanks\" issued by the Bureau of Petroleum and Chemical Industry (SH/T3002-2000) provides empirical formulas for the \"large breathing\" and \"small breathing\" emissions of internal floating roof tanks, which can be used as a reference.

What was said on the 2nd floor makes sense; each issue needs to be analyzed on its own. For ordinary temporary storage tanks, breathing losses are usually the greater concern.

When there is remaining space in the oil storage tank, the liquid oil will evaporate through the liquid surface into the air above, until a certain saturation level is reached. When new oil is added, this portion of oil and gas is discharged. This is what is known as a “deep breath”. And “minor breathing” refers to breathing caused by temperature changes. The volume of oil changes periodically on a daily basis as the temperature rises and falls. As the volume increases, the oil and gas at the upper part are discharged ； When the volume decreases, inhale fresh air. Therefore, if oil is circulated frequently, the loss due to large breathing movements will definitely be much greater. If a floating roof is installed on the oil storage tank, the floating roof moves up and down with the liquid level, thereby eliminating the remaining space and causing the phenomena of large-scale breathing to disappear.

The internal floating roof was created precisely to reduce losses, so this topic seems to have little significance.