What Is Pump Head?How to Calculation,Performance & Classification

When selecting a slurry pump, the pump’s head is an essential consideration. So how do we calculate the head of a slurry pump? How is head classified? How can we achieve optimal pump efficiency? Pansto will provide answers to each of these questions.

What Is Pump Head

Simply put, pump head is the height of the liquid that the pump draws out of the pool, pressurizes it, and then lifts it to a certain position.

The unit of measurement for pump head is meters or feet, and it is an important parameter to measure the delivery capacity of the pump. Combined with the pump curve, it can determine the flow rate that the pump can pump when the pump head is at a specific height.

If you want to understand the pump head clearly, you must first understand the components of the pump head. The pump head consists of suction head, discharge head and total head.

Suction Head

The suction head refers to the vertical height distance between the liquid level in the water pool and the pump suction inlet.When calculating, we need to pay attention that the suction head also needs to consider cavitation and pipe friction.

Suction conditions are also relevant to the pump head.If the suction level is lower,the head measured will be less,and vice versa.The pump’s motor converts electrical energy into mechanical energy,which the pump then imparts into the fluid as pressure.

Raising or lowering the suction level therefore adjusts the potential pressure of the liquid.The more pressure the pump delivers,the higher the head will be.

Discharge Head

The discharge head refers to the vertical distance from the pump outlet to the maximum height the pump can lift the liquid.

Like the suction head, this does not refer to the simple vertical height. In practical applications, we also need to consider the horizontal distance of the pipeline and the friction loss of the pipeline.

Total Head

The total head refers to the sum of the suction head and the discharge head. But it does not mean that this is the total head. There is another important parameter, namely the pipeline loss, which will be explained in detail in the following content.

Read the following so you can understand total head formula calculations more clearly.

Because pump manufacturers cannot know the suction level parameters, they calculate the pump’s total head. To do this, they subtract the total suction head, which is measured as height above sea-level, from the total discharge head.

The next important consideration is how much friction needs to be taken into account. Friction loss depends on the length and size of the pipework, bends, and gate valves, through which the fluid flows. The sum of the head and friction loss will give total head.

Total head is a more reliable indicator of pump performance than pressure because it indicates what the pump can do regardless of the suction conditions. The total head combined with your flow requirement will allow you to choose the right pump.

How To Calculate Pump Head?

Total Pump Head Formula

H=Hd + Hs

H=Total Head

Hs=Suction Head

Hd=Discharge Head

(The total head formula only applies to simple cases.)

When the liquid level is above the pump inlet, the pump is in positive pressure suction, so the suction head is positive. Conversely, the pump is in negative pressure suction, and the suction head is negative. (refer to the figure below)

Notes On Pump Head Calculation: Static Pressure

When we calculate the total head of the pump, we need to pay attention to one issue, the vertical distance between the liquid level and the pump inlet.

When the liquid level is above the pump inlet, the liquid provides static pressure to the pump. Therefore, we can understand that the greater the vertical distance of the liquid level above the pump inlet, the greater the static pressure it provides, and the higher the pump can lift the liquid (note: Also consider pipeline losses).

Factors Affecting Pump Head

1. Pipeline loss:  When fluid passes through a pipe or elbow, it will produce losses such as friction, impact, and vortex.

2. Fluid density and viscosity:  When the fluid we transport is not just clean water, for example, when using a  slurry pump  to transport slurry, silt, etc., the pump needs a higher head to overcome these difficulties.

3. Flow rate:  Generally speaking, the flow rate of a pump is inversely proportional to the head, that is, when the flow rate increases, the pump head will decrease, and conversely, when the flow rate decreases, the head will increase.

Of course, sometimes the relationship is not inversely proportional. Read the following content to learn more about the pump performance curve

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Taxonomy

• Pump Supplier
• Centrifugal Pumps & Pumping Systems
• Pumping System Design
• Pumps
• Slurry Pumping
• Pump
• Pumps and Pumping Systems