Safety distance issue for liquid collection tanks in LNG liquefaction plants
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Is the safety distance between the liquid collection tank and the enclosure in the LNG liquefaction plant’s loading facility also set at 25 meters, just like in the loading facility itself? Should we still refer to a distance of 15m from the sewage tank?
This post was last edited by mfxqy on 2020-6-22 at 18:35. The loading area of an LNG liquefaction plant is so large – why must the liquid collection tank be located near the wall? It indeed needs to be close to the wall, at least 25 meters away; such safety-related distances shouldn’t be constrained by regulations. If possible, keep the distance larger. When an accident does occur, you’ll realize that regulations don’t ensure intrinsic safety, although the ultimate goal of intrinsic safety is to eliminate the need for anything else
15 meters is not sufficient; it must be designed as a loading and unloading facility for liquefied hydrocarbons. The design principle is that it applies to any process equipment and facilities of Class A or B. The distance from the wall must be at least 25m.
In that case, should the safety distance between the liquid collection tanks in the tank area and other facilities be based on the distances specified for storage tanks?
It is reasonable to refer to the cards for Class A process units when considering the accident ponds and liquid storage tanks in the tank farm. Now, accident ponds are generally not designed in this way; it was merely a last resort adopted because the original fire dikes in old plants did not have sufficient capacity.
The liquid collection tank is not the same as the accident tank or the accident storage tank. The accident storage tank serves the same purpose as the fire dike, while the accident tank is designed for storing fire-fighting water and is classified as Category C; the liquid collection tank here is used to hold a small amount of leaked LNG within the fire dike.
Why are liquid collection tanks still needed inside the fire dike? The standards don’t require it. Since there are already fire dikes in place, adding a liquid collection tank for use in the event of an accident serves a purpose; however, sunken pits can easily lead to the accumulation of oil and gas, so it’s better not to install such pits if possible. You are referring to the catch basins used to collect rainwater within the fire dike, right? They are all installed along the fire dike, with no requirements regarding safety distances.
The design standards for natural gas liquefaction plants stipulate that liquid guide channels and collection tanks should be installed within the fire dike, with specific requirements regarding the distance between these collection tanks and the metal tank walls