Understanding NPSH Part 3

By adminbee | March 26, 2019 |

Last time, we looked at how NPSH can be impacted by a poor pump selection, such as using a 3500 RPM pump selected near the end of its published curve.  Sometimes this can be remediated by reducing the pump speed, but not always.  If the NPSHr curve is relatively flat, the speed reduction may help. …

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Understanding NPSH Part 2

By adminbee | March 7, 2019 |

Last time, we saw that as we supply more pressure to the pump suction than what the pump manufacturer requires, we are OK. But that isn’t the whole story: most pumps in HVAC operate over a range of flows, meaning they will change flow rates based on loads or control strategies.  So, what happens as…

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