On the installation and operation of nitrogen sealing for storage tanks

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I. Installation of nitrogen sealing Systems. Nitrogen sealing systems should be considered in the following situations: 1. When storing materials that are prone to oxidation, polymerization, or instability. 2. Spaces within the storage tank where explosive flammable gases can form. 3. Storing oils with high sulfur content can easily lead to spontaneous combustion of FeS. Storage tanks for sulfur-containing gasoline, naphtha, and diesel, which are prone to the formation of ferrous sulfide, should be equipped with a nitrogen blanket. The nitrogen seal valve (or control valve), pressure gauge, and pressure transmitter of the nitrogen seal system should be installed at the platform on top of the tank. Gas connection lines should be provided between nitrogen-sealed storage tanks. A shut-off valve should be installed on the connection line, and a pressure monitoring instrument should also be installed on it. II. Operation of nitrogen sealing: Under normal circumstances, sampling and measuring the height of storage tanks under nitrogen sealing should not be carried out on the tank roof. When it is necessary to work inside the tank, a portable detector equipped with functions for detecting oxygen, flammable gases, and hydrogen sulfide must be worn; if working in an enclosed area, a self-contained breathing apparatus should be used. The operation of the nitrogen-sealed tank should be checked regularly. The roof vent valve is calibrated once per quarter, while the nitrogen seal valve or control valve is tested every six months, with corresponding valid calibration reports available. Before filling the nitrogen-sealed tank with oil for the first time, the oxygen content inside the tank must be tested and found to be within acceptable limits. When nitrogen supply is interrupted, stop the oil transfer operation from the tank.