Height of fire dike for above-ground storage tanks of liquefied hydrocarbons, flammable gases, and oxidizing gases
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This post was last edited by superbbook on 2021-8-11 at 11:20. According to the Fire Protection Design Standard for Petrochemical Enterprises GB50160-2008 (2018 edition), section 6.3.5 stipulates that the installation of fire dikes and partitions shall comply with the following requirements: 1. For liquefied hydrocarbon storage tank groups using full-pressure or semi-frozen systems, a fire dike with a height of 0.6m should be installed. The distance from the base of the dike to the storage tanks should be no less than 3m. The floor inside the dike should be made of cast concrete, and it should slope outward. The partitions inside the fire dike should not be higher than 0.3m； Excuse me, sir: the specification here states that a fire dike of 0.6m is sufficient, but in practice 0.8m was used; however, when the experts inspected it, they said this height was too high. Is this a mandatory requirement? Where does 0.6 meters come from?
It’s not a mandatory requirement, but the experts’ suggestions should be taken into account. Explanation of the provisions: The purpose of installing fire dikes around the liquefied gas tank cluster is to: ① serve as a barrier to prevent unauthorized personnel from entering the tank cluster ； ②The fire dike is low, facilitating the dispersion of small amounts of leaked liquefied gas ； ③Once the leakage volume is large, some liquefied gas will inevitably accumulate inside the dike; this can be detected by combustible gas concentration alarms installed within the dike, which helps to identify the issue promptly and take timely action. It is specified that the height of the fire barrier should be 0.6 m, which is appropriate to the typical installation height of 0.4 m for combustible gas concentration alarms.
It is best to adopt the latest standards; liquefied hydrocarbon storage tanks should be equipped with fire dikes, as these dikes can serve as a barrier to prevent unauthorized persons from entering the tank area； Once the leakage volume is large, some liquefied hydrocarbons will inevitably accumulate within the fire dike, and combustible gas concentration alarms installed inside the dike can detect this, facilitating timely detection and prompt handling. Furthermore, the low height of the fire dike facilitates the dispersion of small amounts of leaked liquefied hydrocarbon gas. Full-pressure and semi-refrigerated liquid ammonia storage tanks, as well as fully-refrigerated single-containment storage tanks for liquefied hydrocarbons, shall be equipped with fire dikes. For fully refrigerated two-sided or fully insulated liquefied hydrocarbon storage tanks, fire dikes may not be required. The construction requirements for the fire dike are as follows: (1) The distance X from the single-containment storage tank for liquefied hydrocarbons to the inner diagonal of the fire dike should not be less than the sum of the difference Y between the highest liquid level in the tank and the height of the fire dike’s top, plus the head pressure equivalent to the vapor above the liquid surface (Figure 4-1). When the height of the fire dike is greater than or equal to the highest liquid level, there is no limit on the distance from the single storage tank to the inner diagonal of the fire dike. (2) The construction height of the fire dike around liquefied hydrocarbon storage tanks should not exceed 0.6 m; the partitions within the fire dike should not be higher than 0.3 m. The floor inside the dike should be made of cast-in-place concrete, and it should slope outward in all directions. The fire dike should be at least 3m away from the storage tank. (3) The distance from a fully frozen liquefied hydrocarbon storage tank to the inner foot line of the fire dike shall be the difference between the highest liquid level of the tank and the height of the fire dike. (4) The fire dike shall be equipped with pedestrian steps or ladders. (5) Fire dikes and separation dikes shall be non-combustible solid protective structures capable of withstanding the static pressure of the liquid they contain as well as changes in temperature, and shall be leak-proof.
Which version of the standard is this? Should it be changed to not exceed 0.6?
The excerpt from the Internet at this time is likely from the 2008 version; the 2018 version specifies that the recommended height should be 0.6 meters.
Total pressure and normal pressure should be treated separately; one cannot treat them as the same thing!
It is not ruled out that the person who offered the opinion is an experienced expert who didn’t have time to review the new regulations; the original 2008 version stated that a fire dike of no more than 0.6m in height should be installed, so 0.8m is considered too high.