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Often, flow of material needs to be split to several destinations. This may be to distribute flow evenly to several units or proportionally between several units. For example, consider sludge flow to four dewatering devices. You may want each of the devices to receive one-quarter of the total flow; this would be an even distribution of flow. Alternately, perhaps one of the dewatering devices has some mechanical difficulty that limits its capacity or you have multiple units with different capacities. In these instances, you may want to disproportionately provide a lower flowrate to that unit. In that case, you may want only 20% of the flow to go to the problem unit and the rest to evenly distribute what is left (e.g., 27% each).

Flow splitting can occur by using individual pumps (or compressors in the case of gases) for each flow stream. Alternatively, valves or gates can be used to split each stream. Variable-output pumps or compressors can better achieve a good flow split than valves or gates because they can act independently of the other pumps or compressors. However, using individual pumps or compressors is typically more expensive, particularly for capital costs.