Let’s talk about some of the mistakes in petrochemical standards over the years, in my opinion

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The last edit to this post was made by The power of a team on 2022-9-26 at 10:22. There are numerous design standards in the petrochemical industry, and inconsistencies are inevitable due to their overlap. Regulatory authorities also state that, generally, the strictest standards should be followed. It takes several years to develop, update, and finally publish a standard specification. Over these years, I have identified what I consider to be errors in such specifications; here are a few examples: Note 5 in Table 6.2.8 of GB50160 states that \"for floating-roof or internal floating-roof tanks used for storing Class B flammable liquids, if the fire separation distance is greater than 15 meters, it can be set at 15 meters.\" ”Is there a mistake with this C B? Should it be C A instead? I have a basis for this question; in the 1992 version of the petrochemical codes, for type C-A floating roofs, when the height exceeds 15m, 15m can be taken as the value). Reference: GB50160-1992, clause 5.2.7, and note 6 in GB50183, section 6.5.7, also refers to type C-A. From a safety perspective, areas more than 15 meters away from Class C-A media are not considered Zone 2. Considering the need to save land, there is no need to increase the safety distance for large Class C-A storage tanks. Upon further case analysis, it becomes even clearer that this Type C B design is absurd; for a dome tank of Type C B with a capacity of 10,000 m3 and a diameter of 30 m, an oil separation distance of at least 5 m is sufficient. However, in the case of internal floating roof or floating roof tanks, the required distance is at least 30*0.4 = 12 m. All store Class B products; the spacing required when there are internal floating disks (not less than 12 m) is actually greater than that when there are no such disks (not less than 5 m). Theoretically, the use of internal floating disks to isolate air should make storage tanks more secure against fires involving flammable liquids, so why is a larger spacing required in this case? It would be appropriate to adjust this value accordingly by referring to the relevant standards. Those who are interested can compare GB50183 and GB50074. 2. According to GB50160, clause 6.2.7, sub-clause 3: \"When there are storage tanks with a single tank volume of 1000 m3 or more and 10000 m3 or less, the number of such tanks shall not exceed 16.\" ； ”How was the restriction on the unlimited number of Class C-B storage tanks in the previous version removed? Will there also be a limit on the number of Class C-B tank groups in the future if the volume of each individual tank exceeds 1000? (However, the provision explanation still includes the statement that there is no limit on the number of C Bs; the standards should be as rigorous as possible.) 3. Is there a mistake in the formula in HGT 20510-2014, Standards for the Design of Instrumentation Gas Supply? It should be divided by 60 instead of multiplied by 60 – please have an expert review this again! 4. Regarding the classification of fire hazard based on a flash point of 45°C, GB50074 and GB50183 classify it as Class B, while GB50160 classifies it as Class A. The previous version of GB50074 was the same as GB50160, but the new version has been modified. Why are these principle-based standards for classifying fire hazard inconsistent? The flash points of diesel grades -35 and -40 are exactly 45°C. Is the reduction in fire risk specified in the new version of GB50074 intended to cut down on investment at the design stage? 5,