Pump Sizing and Power Requirements Objectives:
• You will learn the two functions of a pump.
• You will learn the two pieces of information required to select a pump.
• You will study and appreciate the energy requirements (work to be done) for a pump to accomplish its work.
• You will be familiar with information provided by a pump chart.
• You will understand efficiency and power requirements for a pump powerplant.
A frequent question I receive
from a farmer, nurseryman, or greenhouse operator about pumps is, How many horsepower
pump do I need?
The pump must do two things:
- move the required quantity of water, and
- create sufficient pressure to
make the system work.
These, then, are the two factors involved in selcting a pump.
A pump typically must lift water from a lower level and then push it to a higher
level with enough force to make the sprinkler nozzles or trickle emitters work
properly.
In addition, the power plant -
either an electric motor or an engine - must be sized to operate the pump to
achieve the flow and pressure. There is a two-step process to sizing the correct
pump for a job.
The power plant is not 100 percent efficient due to losses in
power transmission. The power unit needs to be a have greater horsepower than required
by the pump in order to provide adequate usable power.