I have a question regarding self-priming pumps; I only have a partial understanding of it. Please, experts, help me out
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When selecting a self-priming pump, customers sometimes ask about the suction lift. What is the difference between the suction lift of a self-priming pump and its self-priming height? I would also appreciate it if an expert could clarify this, preferably by providing a schematic diagram for an intuitive understanding.
I’m not entirely sure if it’s a problem; let’s see what the commentator says
Suction lift generally refers to the height at which liquid is drawn up, while head generally refers to the height at which liquid is discharged
The pump’s suction head = standard atmospheric pressure – cavitation margin – safety margin. That is, the maximum installation height allowed by the pump. The self-priming height of a self-priming pump should also refer to the maximum distance from the pump’s centerline to the liquid surface. Personally, I think it’s one thing
The suction lift and self-priming height of a self-priming pump can be roughly considered as the same thing, with only a slight difference (in terms of magnitude).
The self-priming height refers to the vertical distance from the liquid surface to the center line of the centrifugal pump’s shaft (or to the center line of the inlet and outlet for vertical pumps)； Suction lift refers to the length from the liquid surface to the inlet pipe of the self-priming pump. Generally, the suction lift is greater than or equal to the self-priming height. This is simple because, in addition to vertical pipes, the piping of a self-priming pump also includes horizontal pipes; in some cases, elbows are also required. Therefore, the length of the pipe from the liquid surface to the inlet of the self-priming pump is basically greater than the vertical distance from the center line of the pump to the liquid surface. The self-priming height of a self-priming pump is fixed; the longer the suction distance, the longer the priming time, and at the same time, the more work is required to overcome pipe resistance!