Does a fully submerged, liquid-contacting internal floating disk belong to the category of lightweight floating disks?
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Notice from the Standards and Quotas Department of the Ministry of Housing and Urban-Rural Development on Issuing the Minutes of the **Standards Coordination Meeting for the Petroleum and Petrochemical Industry: Section 6, Tank Selection; (7) Clarification of the requirements for selecting storage tanks. (1) For storage tanks used to hold liquids with a flash point below 45°C, when the capacity of a single tank exceeds 5000 m3, single-disc or double-disc internal or external floating roof tanks should be used; lightweight floating roof tanks (including stainless steel composite floating roofs) should not be employed. When the capacity of a single tank is less than 5000 m3, aluminum floating roof tanks may be used, but they should be treated as fixed-roof tanks, and nitrogen sealing protection systems as well as oil and gas concentration monitoring systems must be installed. When the storage capacity of a single tank is 50,000 m3 or more, a steel double-disc tank should be used. The material of the floating tray should be selected as carbon steel, low-alloy steel, or austenitic stainless steel, taking into account both the strength requirements and the corrosivity of the stored materials. Discussion result: Approved after modification. Slight adjustments were made to the specific technical measures. Does a fully submerged, liquid-contacting internal floating disk belong to the category of lightweight floating disks? Can a 20,000-liter internal floating roof tank use this type of floating disk?
This post was last edited by cjgj008 on 2018-1-23 at 19:30. When were these meeting minutes issued? Could you send the full text? I searched online everywhere but couldn’t find it. Currently, the internal floating roof we use features stainless steel buoy-type floats; therefore, this approach does not meet the requirements either for tanks with a capacity of more than 5,000 cubic meters. Also, do you mean that the fully liquid-contacting floating pad is a box-type or honeycomb-box-type assembled floating pad? If so, it should also belong to lightweight floating pads or stainless steel modular floating pads. Also, this minutes are quite strange; haven’t they been pushing hard for fully liquid-filled internal floating discs lately? Why not use one with over 5,000 cubic meters for this purpose?
It hasn’t been published yet; it’s a draft for discussion, said to be organized by the fire department
It is said that it has not been officially issued, which means it is not valid.
As far as I know, that minutes have not been officially issued for implementation; therefore, the current standards and regulations should still be followed. When the diameter of a 20,000 cubic meter storage tank is greater than 40 meters, an internal floating roof made of fusible material should not be used. Full liquid contact has its advantages and disadvantages: it can reduce evaporation and minimize the volume of gas space, but in the event of a leak, it becomes difficult to handle during subsequent disassembly. Fully liquid-contacting; available in aluminum and stainless steel versions, but it lacks foam weir plates, which prevents reduction of the amount of foam required in the design. Moreover, its price is high, resulting in poor cost-performance.
I chose the stainless steel float; those made entirely of stainless steel are too expensive
It’s available in the post at https://bbs.hcbbs.com/thread-2734562-1-1.html, but not the full text