I endorse that this approach may be beneficial in high pressure drop systems where the low flow rate may be,for whatever reason, a concern.It is an extra weapon in the armoury
As part of a broader "look-see" I have even used dissimilar flow-rate(1200l/h and 600l/h) pumps in an attempt to address lamellar flow worries . A definite,but unquantifiable,increase in flow rate over the stand-alone 1200l/h pump was obtained.
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