Abhishek Paramasivan, MSME
: Caleb Shafer
: Lab Session #4 Report
The purpose of this lab is to understand centrifugal pumps, determine head, flowrate and efficiencies, and
their overall performances. Additionally, students will gain an understanding of system and pump performance
To achieve this purpose, a centrifugal pump will be started with all valves fully open and the pressure readings
will be recorded from both the suction and discharge nozzles. Then, record the flow rate and calculate the
pressure difference. Repeat the process after closing the discharge valve a bit. After the data has been
recorded, do the following:
1). Plot the Pressure difference vs Flowrate (Pump performance curve).
2). Plot TDH vs Q
3). Calculate the Total Dynamic Head (TDH)
The Results for the labs are enclosed in the attached lab handouts.
Centrifugal pumps power hydraulic systems by a spinning impeller, which pulls fluid in through a suction
nozzle, “throws” it to the perimeter of the casing and keeps it moving in the direction of the discharge nozzle
until the fluid exits. As a non-positive displacement pump, the pressure that this impeller generates is what
creates flow, rather than flow creating pressure as positive displacement pumps do. It is recommended that
fluid power professionals study pump performance curves when specifying a system, or create one if one is not
available, to understand how changing the valve angle will affect the system’s performance.
It is imperative to understand how changing system design affects the head, and consequently the Net Positive
Suction Head, to prevent cavitation. Influential variables include but are not limited to valve angle, vapor