What are the precautions when converting a liquid hydrocarbon sphere tank to hold gasoline components?
Thread Content
What are the precautions when converting a liquid hydrocarbon sphere tank to hold gasoline components? It falls under the category of higher-level guiding lower-level ones; originally, the question was whether it was necessary to go through the approval procedures for pressure vessels Are any other changes required, such as lowering the rating of the corresponding safety valves?
I think if the liquid level indicator is fine, then there are no other problems.
Safety valve issue; the safety valve has been replaced with a breather valve
If the equipment’s voltage tolerance is sufficient, a breathing valve should not be necessary. There should be no issue with insufficient incoming pressure from the upstream device. During the first switch, the liquefied gas components should be vented from the vapor space at the top of the tank.
It seems that positive pressure should be fine; for negative pressure, attention needs to be paid to replenishing nitrogen.
The safety valve was replaced with a breather valve, and the level gauge was appropriately modified or calibrated.
Connect the existing vapor equilibrium pipeline to nitrogen for nitrogen sealing; the safety valve pipeline can be disconnected. Install an exhalation valve so that what is exhaled is primarily nitrogen, and the same applies to the air inhaled, thereby eliminating safety hazards and reducing losses due to vaporization of the medium
In my opinion, when converting a spherical tank for use with gasoline, it is sufficient to pay attention to the following issues: 1. Isolate the vapor phase from the flare system； 2. The safety valve does not need to be modified, as it is used to protect the tank ； 3. When negative pressure occurs, nitrogen should be replenished promptly; therefore, the nitrogen seal valve needs to be increased ； 4. The power requirement of the transfer pump needs to be calculated, as the density of the medium is quite high ； 5. The sampling facilities need to be upgraded.
It’s fine to use it at a high generation with low usage. However, the auxiliary facilities need to be recalculated and configured to meet gasoline operating conditions. The safety valves and drainage system need to have their pressure settings reset or modified