Are nitrogen seals mandatory for Class A and B liquid storage tanks?
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Are there regulations requiring the installation of a nitrogen blanket for Class A and B liquid storage tanks?
SH3007 4.2.5 4.2.10 GB50160 6.2.2 6.2.4A
The vapor pressure at storage temperature is below atmospheric pressure, making it unsuitable for open storage (high volatility, sensitivity to oxygen and water, environmental pollution, toxicity). . . ), it is unreasonable to use an internal floating roof due to capacity constraints.
Nitrogen sealing is primarily used to reduce the generation of breathing off-gases from the liquid. But this depends on the properties of the material. For example, substances that tend to self-polymerize such as acrylic acid and styrene require the addition of polymerization inhibitors. Some polymerization inhibitors require low-concentration oxygen for activation. If you use nitrogen sealing, the entire contents of the tank will polymerize spontaneously, resulting in complete waste.
Petroleum standard 7.2.9: Class A and Class B A equipment and pipelines shall be equipped with inert gas purging facilities.