Can an emergency pump be installed inside the cofferdam?
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Inside the dike of Class A tank areas, there is a collection pit where minor leaks and rainwater accumulate. Above this pit, there is an emergency diaphragm pump designed to pump the water from the pit into barrels outside the dike. Is it appropriate to use such a diaphragm pump? Thank you all!
This is a safety inspection finding that requires us to move the pump outside the tank area. I checked GB50160, and it only contains requirements for tank transfer pumps and pump rooms.
Shouldn’t the pump be outside the cofferdam? It seems that your pit wasn’t designed in accordance with the specifications.
This isn’t a transfer pump, but it will work. It is installed on the outside to prevent fires caused by leaks from the transfer pump (of course, the pump area also has enclosures or drainage ditches) ； This pump is installed inside and is used for pumping rainwater; it’s not very relevant! But there’s a question: isn’t it supposed to be possible to install water seal wells outside the dike? This kind of accumulated water could be handled through the water seal well’s water intake system, so pumps wouldn’t be necessary, right?
Hello, the pit inside the cofferdam is connected to the water seal well outside the cofferdam, with a valve in place to control this connection. In the event of a minor leak, we close the valve to prevent the leaked material from entering the water seal well and then flowing into the water treatment system. After controlling the leak, use a diaphragm pump to transfer it back into the tank truck or IBC.
If your diaphragm pump is powered by compressed air and is used only for transferring sewage, I think there should be no problem with installing it inside the cofferdam. But if it’s an electric pump, then it won’t work.
The reason why pumps cannot be placed inside the cofferdam is, first, that in the event of an accident and a leak, it would be difficult for personnel to approach and operate them. Another reason is the concern that leaking conductive liquids could cause electric leakage in electric pumps; since this is a pneumatic pump, I don’t think there’s a risk of electrical leakage. But what if the storage tank ruptures and there is a large-scale leak? Wouldn’t it still be problematic to try to operate the pump when the area inside the cofferdam is filled with liquid? In my opinion, it’s safer to place submersible pumps in the sump, or self-priming pumps outside the cofferdam – that’s just my personal view
Thank you for your suggestion. The air supply control for the pump is located outside the cofferdam; therefore, even in the event of a large leak, it is not necessary to go inside the cofferdam to carry out any operations.