Thank a lot, BigInch. Please allow my ignorance again. I wanna add once again what I think about the test procedure to make it sure.
1) A pump is running at flow(A) and speed(B) with TDH(C).
2) When the suction valve is piched down a little bit to reduce NPSH, the pump TDH will be rising a...
Thanks again, BigInch. You mean they need two suction valves at least for the test; one is near the pump impeller suction for reducing NPSH, and the other is to control the source flow rate far upstream. They do not modulate the discharge valve. I still wonder if this means the same as Artisi's...
BigInch, please allow my ignorance. What I want to know is how to keep a constant flow in the NPSHR test to get the 3% drop-off curves while piching down suction valve. For example, at an initial test point, there is one set of flow-head-NPSH at constant speed. To get a second point of reduced...
Thanks, Artisi.
If they have to open the discharge valve in order to return to original flow, I do not think they can get many data points of NPSH for a constant flow rate. Do they experience some limitations on the number of points available? How about changing the static lift instead of...
In NPSHR tests, when a suction valve is piched down to reduce NPSH, the pump flow is of course reduced accordingly. How can they keep the flow unchanged ? The 3% drop-off curves are for constant flow and speed.
