Air separation oxygen production area: [Weekly Topic] Week 16 of 2011——Is it better to maintain positive or negative pressure in gas station tanks?
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This post was last edited by gader on 2011-4-18 at 22:50. Recently, while researching, I learned that some aircraft engines have fuel tanks under negative pressure, while others are under positive pressure (with nitrogen filled). I’m not sure what the advantages and disadvantages of each are
In my opinion, for the lubricating oil station of an expander, it is better to maintain a moderate negative pressure; this brings many advantages, such as facilitating gas separation and reducing cavitation in the oil pump, and so on
In my opinion, maintaining negative pressure ensures smooth oil return and reduces the likelihood of oil leakage. Generally, nitrogen is used to protect the fuel tank only when the engine unit is not in operation for an extended period/is on standby.
Maintaining negative pressure has some benefits for the oil return of the equipment
Under normal circumstances, a negative pressure is maintained at the fuel station to facilitate oil return and prevent contamination of the medium; if it is stored in a warehouse, positive pressure protection is used
Negative pressure in the fuel tank is created to draw out the oil vapor generated at various lubrication points. As for filling it with nitrogen, it’s not necessary; it should be equipped with a reservoir and inflated as needed. Additionally, negative pressure has nothing to do with oil return; it simply exists between the oil return pipe and the oil vapor being drawn out. (For reference)
The fuel tank in a gas station is usually evacuated using exhaust fans to create a negative pressure inside the tank, thereby ensuring smooth oil return
A slight negative pressure is good, as it prevents oil leakage and thus avoids mess and dirt in the equipment.
The exhaust fan creates a negative pressure in the fuel station system to prevent oil from leaking out. If the fan stops, it can cause poor return of oil in the pipeline, leading to oil leakage from the high-level tank; in such cases, an ejector should be added or a bypass should be installed in front of the exhaust fan to allow the oil to flow directly into the atmosphere. The purpose of filling with nitrogen may be to prevent oil oxidation and ensure safety.
It is related to the system requirements and the type of compressor seal! Negative pressure is generally used; for example, compressors employ floating ring seals, and nitrogen sealing is required when compressing explosive materials. The gases released from the degassing tank enter the flare line together with these gases. Nowadays, this type of seal is gradually being replaced by dry gas seals.
A slight negative pressure is preferable; our gas stations must be equipped with exhaust fans to draw the oil vapor out of the tanks and discharge it outside