Density is a fundamental physical concept - but it's also a key to understanding, choosing and managing the right flow solutions. In short, density describes how much mass a substance has in a given volume. In other words, it's a measure of how densely the substance is packed. This is crucial when working with pumps, valves and flow measurement in demanding industries such as pharma and food.

What exactly is density?

Density - or bulk density - is the ratio of mass to volume. It is typically measured in kilograms per cubic metre (kg/m³). Think of it as the density of a material. For example, water has a density of 1,000 kg/m³, while heavier liquids such as acids or oils can have significantly higher values. Density also depends on both temperature and pressure - which is why it's important to have accurate measurements and the right equipment in process environments where even small deviations can have a big impact.

Why density is important

From component selection to process optimisation, density is not just a technical quantity - it's a crucial parameter in everything from component selection to process optimisation. When choosing a pump, the density of the fluid determines how much force is needed to move it. The same goes for sizing pipes and calculating flow. In pharmaceutical and food production, density is also used for quality control: changes in density can reveal contamination, incorrect dosing or errors in production. Therefore, precise knowledge of the density of the medium helps to ensure both product quality and reliability.

How is density calculated?

The formula is simple:
Density = mass / volume

A concrete example: If you have 1 litre of liquid with a mass of 1.2 kg, the density is 1,200 kg/m³. But even though the formula is simple, an accurate calculation requires the right equipment and stable process conditions. In practice, density is often measured with sensors, flow meters or weight and volume measurements - depending on the application and accuracy requirements.

Understanding density in practice

Density helps determine which components you need to use in your process - and how to set them up. A high-density fluid requires a more powerful pump and more robust valves. At the same time, density is used to identify liquids, detect changes in composition and control separation, dosing and flow with great precision.

In regulated industries like pharma and food, it's crucial to keep track of every detail - including density. It's about traceability, quality and safety. That's why it's important to choose solutions and partners that understand the requirements and help put them into practice.

Get our advice on density

At Alflow, we help you find the solutions that match both the density of the medium and the requirements of your process. Whether you work with liquids, gases or mixtures, we have the components and experience to ensure stable operation and proper documentation.

We offer pumps, valves and measuring equipment sized for your specific application - and we're ready with advice to help you optimise both quality and efficiency.

➡ See our range of pumps
➡ See our range of valves
➡ Read more about our work in pharma
➡ Read more about our solutions for the food industry
➡ Contact us - we are happy to advise

FAQ about density

What does density mean?
Density is a measure of how much mass exists in a given volume of a substance. It shows how densely the substance is packed - and is typically expressed in kg/m³.

How do you find density?
You measure the mass and volume of the substance - and divide the two. The formula is: mass / volume.

Are mass and density the same thing?
No - mass is a property of the substance (kg), while density is the ratio of mass to volume.

What does density mean?
Massefylde is the Danish word for density - and is used synonymously, especially in technical contexts.

Do you have questions - or need help choosing the right solutions?
So... get in touch with us here - We're easy to talk to.