Code for Building Design 4.2.2 and Code for Building Design 4.2.3
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Dear experts, I’m not very clear regarding the applicability of these two provisions in the Building Code to Class C storage tanks as specified in GB50016. Specifically: According to Article 4.2.2, the fire separation distance for above-ground fixed-roof Class C storage tanks should be 0.4D; however, per Note 6, when the capacity of a single tank is less than 1,000 cubic meters, the fire separation distance should be 2 meters. If the diameter of a Class C liquid storage tank is 3m, then 0.4D would be 1.2m; in this case it does not meet the requirement specified in Note 6, but it still meets the 0.4D requirement given in the table. What should be done in such a situation? Paragraph 4.2.3: For tank groups that meet the requirements, there is no limit on the fire separation distance between tanks storing Class C liquids. Both this and item 4.2.2 are in bold font and are mandatory. Are these two rules applicable in that situation? For example: In a tank cluster, there are 2 rows with 4 asphalt (Type B) storage tanks each; the volume of each tank is 300 cubic meters, and the diameter of the tanks is 3 meters. There are two values regarding the distance between the tanks: 1.3 meters and 0.7 meters. According to clause 4.2.2, 0.7 m does not meet the requirement of 0.4D; per note 6 to clause 4.2.2, all spacing values fail to meet the 2 m requirement. It meets the requirements as there is no need for a fire separation distance per clause 4.2.3. How is this situation calculated? GB50160 the petroleum standards are very clear; Article 6.2.8 outlines it clearly.
The last edit to this post was made by Young Zhang Fugui on 2018-12-27 at 11:07, with an additional question added: According to Article 4.2.3, Clause 2 of the building codes, the storage tanks within a group should not be arranged in more than two rows. This sentence is in bold and means “should”. So is this different from clause 4.2.5 again? Cylinders with more than two rows are not applicable to clause 4.2.3, right? The multi-row arrangement complies with Article 4.2.5. As another example, if three rows of storage tanks of the same type, classified as Category C, are arranged in this way, does that mean they are not considered to be arranged in groups? In that case, can’t we use requirement 4.2.3 to determine the spacing requirements; should we instead use 4.2.2? Does that mean that clauses 4.2.2 and 4.2.3 are in an OR relationship, so it’s sufficient to meet one of the conditions, without the need to meet both? 4.2.2 is a general requirement, and 4.2.3 is a specific requirement; however, both are in bold font
I asked experts before, and that was their reply; take a look: in a tank farm, the storage tanks are organized into groups, and actually there must be at least four rows – two rows make up one group – only then can it be called a tank group. I’m not sure if this expert’s explanation is correct
Is that what it means? Since grouping is necessary and the arrangement is based on tank groups, then this tank area must contain at least 2 different substances/tanks; a tank area with tanks containing the same type of substance does not count as a separate tank group? You explained this from the perspective of quantity on the surface; for similar substances, if there is a large amount stored in tanks, can they also be grouped? I’m completely confused now...
It has nothing to do with the materials; it depends on the number of storage tanks. Two rows don’t count, no matter how many tanks are in each row; at least four rows are required for it to be considered valid
Is it possible that your understanding of the regulations is incorrect? First, according to clause 4.2.2, the fire separation distance for fixed-roof storage tanks of category C above ground should be no less than 0.4D; per note 6, when the capacity of a single tank is less than 1000 cubic meters, the fire separation distance should be no less than 2 meters. How come coming to you has turned into something that’s supposed to be done? Here, both the requirements of the table and the notes need to be met, that is, actions should be taken based on the greater distance
Thank you. I understand this 4.2.2; the tables and Note 6 need to accommodate large amounts of data. The main concern is clauses 4.2.2 and 4.2.3; the requirements for the grouped arrangement of these small tanks should be more relaxed. I don’t know what constitutes a grouped layout
This post was last edited by Young Zhang Fugui on 2018-12-29 at 10:43. According to “Code for Building Design 4.2.3, clause 2, the storage tanks within a group should not be arranged in more than two rows”. Does having only 2 rows of small tanks constitute one tank group or two tank groups (with one row counting as one group)? For 4 rows, should it be divided into 2 to 4 groups?
Yeah, what you say doesn’t count. Think about it slowly by yourself
The arrangement of small storage tank groups must also ensure that there are no more than 2 rows; if there are more than two rows, they should be divided into several separate tank groups