How to select pumps for rainwater discharge from LNG liquid collection tanks
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Dear LNG experts: I would like to ask whether, for draining rainwater from the LNG collection tank, it is better to use temporary pneumatic pumps, or to install two dedicated pumps next to the tank What specifications should be referenced? Thank you.
The rainwater within the station is collected through various branch pipes and then discharged via a single pipe with a diameter of DN2400 (the elevation at the center of this pipe is 1.95m, and the slope of the drainage pipe is 0.001) to the already constructed rainwater discharge outlet. To prevent seawater from flowing back, steel gates are installed at the discharge outlet; however, only main drainage pipelines have been laid in the area where 3 new storage tanks are located, and additional branch rainwater drainage facilities are needed in this area. Near the new tank area in Phase II of the project, rainwater pipes will be installed to connect to the plant’s main rainwater network; these rainwater pipes will be made of reinforced concrete. “According to the design specifications, there are no dedicated pumps shown on the drawings; it is recommended to add temporary pumps if rainwater cannot be drained in a timely manner. ”
It’s more reliable to ask the design institute for standardized solutions, right?
Come and learn*, thanks to the OP for the gold coins
There are no specific regulatory requirements; it is necessary to drain the liquid from the collection tank in a timely manner to ensure that in case of an accidental leak, the volume requirements for LNG are met. How to configure it should take into account practical operation convenience; fixed pumps are more convenient.
This post was last edited by A few people on 2021-11-17 at 20:13. I understand that the original poster is asking how to collect and drain the water in the puddles inside the cofferdam, rather than how to divert that water after it enters the collection pipes. Incidentally, were there any standardized guidelines in China back in those days? Were there practices similar to what you mentioned later, namely using elevation differences to allow the water in the tank area to flow naturally into pools at lower elevations, from where it could then be pumped out? The various domestic regulations that are applied arbitrarily set requirements regarding the height and volume of LNG cofferdams, which forces designers to lower the floor level inside the cofferdam further and further (I have seen in several cases the floor level inside the cofferdam be more than 1 meter lower than that outside the cofferdam; not to mention the water collection pits). It’s basically impossible to rely on gravity flow due to the height difference.