A Handy Guide to Pump Head Calculation

Many industries depend on pumps for a number of applications. These applications revolve around the extraction and transference of fluid. This could be anything from wastewater to oil and chemicals! Yet, for a pump to be able to handle these varied industrial applications, understanding pump head calculation is essential. 

This, as the name suggests, is highly mathematical, and you may be encountering pump head calculation for the first time, which is why we at Pump Works explain everything you need to know below. 

What is pump head calculation?

A ‘pump head’ refers to a physical amount that expresses just how much fluid your pump can lift or transfer above its current position. 

By calculating this amount, you can understand how powerful your pump is and what it can be best used for! This also helps industries determine which pump they should choose for their operations, depending on the fluid that needs to be transferred. We at PumpWorks are well-able to advise on choosing the right pump for your business; our range of products is extensive, and all have different lifting heights.

How do I calculate the head of a pump?

Pump head calculation is best approached as a series of equations that, once solved separately, combine to amount to the total measurement of your pump head. Each equation represents an important component of the pump head itself.

First, let us consider the static head (abbreviated as Hs) and the velocity head (Hv). 

The static head represents the vertical distance between a pump’s suction and discharge points. Measuring this accounts for the potential energy change in your fluid due to elevation, and thus is integral to understanding how your pump operates! 

As a measurement, the velocity head also accounts for the kinetic energy exerted upon a fluid as it moves through the pump. 

To calculate the velocity head, use the following equation:

Hv=V^2/2g

We can break the equation down as:

• Hv = Velocity head (meters)
• V = Fluid velocity (m/s)
• g = Acceleration due to gravity (9.81 m/s²)

Next, it’s necessary to calculate the pressure head (Hp). The pressure head represents the energy added to a fluid by the pump in an attempt to overcome pressure losses in the system. Bernoulli’s equation is extremely important here. The equation is:

Hp=Pd−Ps/ρg

Here, the abbreviations refer to:

• Hp = Pressure head (meters)
• Pd = Pressure at the discharge point (Pa)
• Ps = Pressure at the suction point (Pa)
• ρ = Fluid density (kg/m³)
• g = Acceleration due to gravity (9.81 m/s²)

Finally, we must calculate the friction head (Hf), a measurement that accounts for energy losses generated by friction in your pump system. This must be done using the Darcy-Weisbach equation, which is as follows:

Hf=fLQ^2/D^2g

The abbreviations refer to:

• Hf = Friction head (meters)
• f = Darcy friction factor (dimensionless)
• L = Length of pipe (meters)
• Q = Flow rate (m³/s)
• D = Diameter of pipe (meters)
• g = Acceleration due to gravity (9.81 m/s²)

This leads us to the total pump head calculation, which is abbreviated as H. This is all of the components combined together, and should give you the exact quantity that your pump head represents! 

H=Hs+Hv+Hp+Hf

A key part of pump head calculation is understanding the flow of energy in a pump system, and the factors that affect this. You know your pump is up to the task if your calculations meet the energy requirements of your fluid transport system!

For the cost-effective purchase of a new and innovative hydraulic pump, contact PumpWorks. New Zealand has long depended on us to handle all your industry-specific, pump-related needs! Assuredly, our customers know that the quality of our work never falters, and nor does the excellent condition of our products.