How can the outlet pressure of a pump be higher than the head specified on the nameplate?
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How can the outlet pressure of a pump be higher than the head specified on the nameplate? The head indicated on the nameplate of our circulating water pump is 44 m, while the pressure gauge at the pump’s outlet shows 0.56 MPa
1. First, rule out any issues with the pressure gauge readings. 2. If the pressure gauge is working fine, then the flow rate at the pump’s outlet must be low; however, this phenomenon should not occur. 3. This phenomenon can also occur if the pressure at the pump inlet increases.
Exit pressure minus inlet pressure, then divide by density and 9.8, and check to see if it’s correct~
It is related to the medium density, inlet pressure, and outlet flow rate
This is a performance curve; if you open the outlet valve wider, the head pressure decreases
Centrifugal pumps all have a performance curve, which shows the variations in power, efficiency, and head at different flow rates.
Is it because the pressure at the pump inlet is too high?
It is very likely that the opening degree of the outlet valve is low
For pumps with a constant speed, does fully opening the inlet and outlet valves correspond to the optimal operating point, that is, the operating point indicated on the nameplate?
At the pump outlet, check whether there is any reduction in diameter; if so, determine whether the reduction is excessive. Also, verify whether the pressure gauge is accurate – calibrate it or replace it if necessary.
Take a look at the performance curve. What is the flow rate at an outlet pressure of 0.56 MPa? Is it the same as what is measured in reality? Pumps all have a specific range of operating curves. It can be adjusted according to the size of the outlet valve.