13 March 2023

In any fluid transportation system, whether it is used for water distribution, oil and gas transportation or industrial applications, the performance of the pumps plays a crucial role in achieving the desired results. The performance of a pump is affected by various factors such as the design of the impeller, the size of the pump, and the operating conditions. To assess the performance of a pump, a pump performance curve and system curve are used. In this article, we will discuss pump performance curves and system curves in detail.

Pump Performance Curve

A pump performance curve is a graphical representation of the performance of a pump under different operating conditions. It is a plot of the pump's flow rate against its head (pressure) at different speeds, impeller sizes, and other parameters. The performance curve provides valuable information about the pump's efficiency, power consumption, and the range of operation.

The performance curve of a pump is obtained by conducting tests on the pump under different conditions. The tests are carried out in a test rig or in the actual system, and the results are plotted on a graph. The pump performance curve is usually provided by the pump manufacturer and is used to select the most suitable pump for a specific application.

The pump performance curve is a crucial tool for the pump operator as it helps in understanding the pump's behavior under different operating conditions. The curve can be used to determine the pump's efficiency, the head required to achieve a certain flow rate, and the power consumption at different operating points.

The pump performance curve has three important parameters:

1. Flow rate: The flow rate is the volume of fluid that the pump can deliver in a given time. The flow rate is usually expressed in cubic meters per hour (m3/h), gallons per minute (GPM), or liters per second (l/s).

2. Head: The head is the pressure required to move the fluid from the inlet to the outlet of the pump. The head is usually expressed in meters (m) or feet (ft).

3. Efficiency: The efficiency is the ratio of the output power to the input power. It is expressed as a percentage.

The pump performance curve is a useful tool in selecting the right pump for a specific application. The curve provides information about the pump's performance under different operating conditions, which helps in selecting the most suitable pump for the system.

System Curve

A system curve is a graphical representation of the system's performance under different operating conditions. It is a plot of the system's head (pressure) against the flow rate. The system curve is obtained by measuring the head loss in the system due to friction, bends, valves, and other components.

The system curve is used to determine the total head required by the system to transport a given flow rate. The total head is the sum of the static head (pressure at the inlet and outlet) and the head loss due to friction and other components.

The system curve is a useful tool in designing a fluid transportation system. It helps in determining the size of the pump required to meet the system's flow and head requirements.

The system curve has two important parameters:

1. Flow rate: The flow rate is the volume of fluid that the system can transport in a given time. The flow rate is usually expressed in cubic meters per hour (m3/h), gallons per minute (GPM), or liters per second (l/s).

2. Head: The head is the pressure required to move the fluid through the system. The head is usually expressed in meters (m) or feet (ft).

The system curve is a crucial tool in designing a fluid transportation system. It helps in determining the size of the pump required to meet the system's flow and head requirements.

Pump Operating Point The pump operating point is the intersection of the pump performance curve and the system curve.