someone explain me is this is a mistake on the video, at 9:50 it says to use the pump discharge valve to restrict the flow , but since the pump works in RPM, the flow would be the same , by close/opening the valve only the speed of the liquid would change and the pressure , but not the volume, for example the water hose in our gardens, if you put your finger on the exit
Centrifugal pumps are not positive displacement pumps. Their liquid delivery can be controlled by throttling discharge (side) valve. Throttling the discharge valve on a centrifugal pump is a common method to restrict flow, but it's important to understand how it works and its potential consequences. How it works: Valve Restriction: When you partially close the discharge valve, you create a restriction in the pipeline. This restriction increases the resistance to flow. System Curve Shift: The increased resistance alters the pump curve, which represents the relationship between flow rate and head (pressure) required by the system. The pump curve shifts upwards and to the left. Intersection with Pump Curve: The new system curve intersects the pump curve (which represents the pump's performance characteristics) at a lower flow rate. This means that the pump delivers less fluid when the discharge valve is throttled. More info at www.pumpsandsystems.com/how-do-throttling-valves-affect-system-curve
Line up the ballast pump for Ballast/DE ballast. The Discharge valve must be shut. Start the Electric pump . Open the Discharge valve . Normally Cargo oil pumps are run on steam, so i assume you talking about electric pumps for ballasting.
