How to carry out this task – Replace the existing submersible pump in the oily wastewater tank with a self-priming pump.

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This post was last edited by henjuese on 2017-2-12 at 10:27. Here’s what happened: The pumps used in our company’s oily wastewater tanks are long-shaft submersible pumps (as shown in the diagram). The depth of the wells is 5300 mm. Due to the frequent need for repairs and the difficulty involved in maintaining these pumps, our maintenance department submitted a request to replace them with self-priming pumps (as shown in my own design; the self-priming pump is placed slightly farther away from the wastewater tank, out of concern for potential explosions during installation – it’s quite frightening just thinking about it. Our wastewater tanks have not been thoroughly cleaned since the company started operating, despite having undergone two maintenance sessions). However, after reviewing the installation manual provided by the self-priming pump manufacturer, things became even more dangerous. The regulations regarding the layout of the suction pipes for self-priming pumps are as follows: “2) The length of the horizontal pipe may be 10 times the diameter of the suction nozzle, but must not exceed 1 m (10D ≤ ℓ < 1.3). 3) The length of the suction pipe should be within 7.6 m (10D + 6.1 m).” In order to shorten the length of the suction pipe (so as to reduce the time it takes for air to be expelled from inside the pipe when the pump starts up, thereby improving the pump’s response time), our management proposed placing the self-priming pump on top of the existing tank cover (the cover is integrated with the tank walls and is made of reinforced concrete; its thickness is 200； The weight of the pump is 249 Kg ； Therefore, it is necessary to cut grooves in the cover plate, remove the rebar from that plate, and weld the rebar of the self-priming pump’s foundation to it, so that the foundation of the self-priming pump and the original cover plate form a single unit ； But this approach is too dangerous; the slightest carelessness can lead to an explosion. My manager is also aware of the risks associated with this method, and has suggested using manual labor to chisel slowly, instead of an electric hammer... I have already expressed my concerns to my supervisor – if it’s necessary to make cuts in the cover plate, I’m not willing to do that job, as it could result in loss of life! Please, fellow sailors, help me out – how should I go about this task?