Is there something wrong with this process design?
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The parameters of the pump are: flow rate of 100 m3/h, head of 70 m. Pipes 1 and 2 do not carry flow simultaneously; the flow rate required for Pipe 1 is 50 m3/h, with a pump outlet head of 55 m ； Pipeline 2 requires a flow rate of 100 m3/h and a head of 70 m. When flow passes through pipeline 1, a portion of the fluid returns to the storage tank. Is there any problem with this design?
Personally, I think the LV level control valve should be replaced with an FV flow control valve. This control valve is used to prevent the pump from being damaged due to high pressure buildup, which can occur when the flow rate at the pump outlet is low. Setting it as an LV level control valve does not achieve the effect of preventing pressure buildup in the pump.
The diagram isn’t very complete; in terms of pumps, a higher flow rate should correspond to a lower head
It is feasible based on the pump’s performance curve: lol
Isolation valves should be added to Line 2 in order to separate Line 1 from Line 2
There is a shut-off valve, it’s not visible in the photo
This design is acceptable. There’s definitely no problem with material flow through pipeline 2 ； When material is flowing through pipeline 1, the flow rate is only 55 m3/h, and the head is also lower than the pump’s rated head. Setting up some backflow of the material serves to prevent the pump from operating under high pressure for extended periods, which is beneficial for the pump’s seals. Personally, I think it would be better to convert this pump to variable frequency control.
For pipelines with such high flow rates, butterfly valves or gate valves are more economical and practical; I agree with using variable-frequency motors on the 9th floor, which would allow us to eliminate Pipeline 2 as well
It is not clear where the backflow occurs in pipeline 1; is it necessary to strictly control the pressure? If so, a pressure control valve needs to be installed. Additionally, the orifice plate on pipeline 2 should not be placed in this location – it should be placed behind the ball valve on pipeline 1, so that the operation of pipeline 2 does not interfere with the removal of this orifice plate.