Can the low liquid level in a floating roof tank with a nitrogen seal be drawn below the floating disk? Standard SH/T3007 states that drawing is not allowed; the reason is fear of air entering...
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Can the low liquid level in a floating roof tank with a nitrogen seal be drawn below the floating disk? Standard SH/T3007 states that pumping should be avoided to prevent entry into the gas phase; but since I have applied a nitrogen seal, is it still necessary to consider this?
No, according to the fifth rule of the ten prohibitions for irrigation areas: during operation, the floating disk of an internal floating roof storage tank must not touch the bottom; air can enter the interlayer and form a mixed explosive gas
But I’ve applied a nitrogen seal, which completely prevents air from getting in – do I still need to consider that?
A ban is just a ban; no exceptions are mentioned! If one thinks that doing so is fine, that nothing happens and no one discovers it, then of course there’s no problem. But once something does happen, or even if nothing happens but the violation is detected, it becomes a liability incident, without any exceptions.
Actually, I’ve done some research as well; the ban doesn’t mention nitrogen sealing, and the reason for that is to prevent explosions caused by air entering. Since nitrogen sealing eliminates the possibility of air getting in, I have my doubts. Indeed, designers should be cautious, but it’s not good to rule everything out outright without questioning it. Many regulations indeed involve such blanket approaches
Thank you very much for saying that: handshake
Nitrogen sealing is a technical method, but it can fail at times and still poses safety risks; to prevent such risks, other technical methods are also necessary； So isn’t it easier just to ban it outright? Why must it be drawn below the floating platform? It’s just to save some working capital; for safety reasons, it’s better not to cut corners.
Well, I can only turn the tank into a non-standard one for now. Yes, there won’t be any funds left by then, so it’s better to be safe. Thank you very much :)
Well, I can only turn the tank into a non-standard one for now. Yes, there won’t be any funds left by then, so it’s better to be safe. Thank you very much :)
The nitrogen seal is placed above the floating disk, mainly to prevent safety accidents caused by backflow and deflation of the tank