Air compressor water separators are a crucial component in any compressor – the better your water separator, the longer your compressor will remain in optimal condition, and the lower the risk of any contaminants!

  • Compressed air and water – simply put – don’t mix.

Water ingress can cause no end of problems, including air contamination, rust and oxidation. 

In some applications, this can be massively detrimental to the accuracy of your work or the integrity of products being manufactured!

Let’s explain what an air compressor water separator is, what it does, and how it works.


What is an Air Compressor Water Separator?

The task of a water separator is to ensure that any contaminants don’t impact the compressed air.

When you use compressed air in any production or technological application, you want the air to be free of water vapour. Water is naturally present in all ambient air, so it’s vital to filter out the molecules to ensure they don’t erode the compressor equipment.

As compressed air is put under pressure, the trace elements of water are forced out – and that water needs to go somewhere!

In most compressors, that destination is the air tank, so you’ll see a drain valve on the bottom of the tank. Draining the tank is an essential maintenance task.

Water separators don’t just remove vapour – they also remove:

  • Solid particles or trace elements.
  • Oil and oil vapour.
  • Liquid water.

So, an air compressor water separator works to remove that water vapour, and other potential contaminants, from the compressed air and make sure it doesn’t make its way onto your tools.

How Does an Air Compressor Water Separator Work?

If you’re interested in how your air compressor water separator works, there are two primary methods.

Both are effective, so a lot depends on what sort of compressor you have, which water separator is most compatible with your equipment, and the processes you carry out.

The two types of water separator are:

  1. Centrifugal separators
  2. Coalescing separators

One option uses a rotary action, and the other a filter, both with the same objective to ensure that no water or other molecules can mix with the compressed air.

  • Centrifugal separators produce a spinning action applied to the compressed air as it travels through the water separator. The rotary motion makes the contaminants move faster and move towards the housing where water and particles drain.

You can have an air compressor with an automated draining system or can manually drain the water separator.

  • Coalescing separators perform the same job but with a filter that catches water and other particles. The filter medium traps contaminants, as compressed air is pushed from one side of the filter to the other, allowing the compressed air to exit.

Filter elements in a coalescing air compressor water separator need to be cleaned and replaced to ensure they remain in excellent condition.

What Should I Look for in an Air Compressor Water Separator?

Choosing the correct water separator very much depends on what sort of air compressor you use and for what application.

For example:

  • Painting applications require accurate regulators and clear readouts through the gauge to ensure there is no water impacting the paint’s finish and colour.
  • Drainage systems can be automatic or manual, or you can opt for push-button drains to control this process.
  • Water separators can be tool-mounted for ease of use.
  • A water separator with a robust casing is essential for high-volume air compression, so the separator itself is resistant to contaminants and solvents.

The best water separator will be suited to your air compression procedures and fit in with maintenance schedules to ensure it remains in excellent condition.

Is an Air Compressor Water Separator Important?

Contaminants in compressed air can be hugely destructive, and few as much as water. Vapour can cause tools, machinery and equipment to start to rust and break down quickly.

For example, if you use compressed air in a manufacturing process, each time the hydraulics operate, water vapour is released if the water separator isn’t working correctly.

Over a short space of time, continued exposure to dampness will start to make tools deteriorate, creating downtimes and extra costs in repairing, maintaining, servicing or even replacing essential tools and equipment.

Every air compressor will have some water exposure.

The air pump compresses air, which consequently becomes warmer. When that compressed air reaches the air tank, it cools and releases water vapour as condensation.

Without a water separator to remove that vapour, the air compressor itself can corrode, with any water making its way down the air hose impacting tools and machinery.


Contact AMS Compressors for your air compressor maintenance and air compressor repairs.