Do I Need An Oil / Water Separator?

Do I Really Need Oil / Water Separators?

Oil & water separator range

Clearly an oil/water separator does a job. But isn’t that what inline filtration is for? So do you really need one?

If you want to be picky about such things, no, technically speaking, you don’t need a separator.

By that we mean your air compressor will continue, for a while at least, to deliver pressurized air without a separator.

But in every practical sense, a separator is a vital part of the compressed air system in most setups, with one major exception:

Do oil-free compressors need a separator?

Oil-free compressors, as the name suggests, don’t use oil so there’s nothing to separate. You don’t need an oil/water separator with an oil-free compressor.

OIl & water separator illustration

You will, however, need a separator to do all of the following:

Trap oil (as opposed to just catching it)

Think of it like this. During a busy night, the police make lots of arrests and put everyone in the back of their van. Pretty soon the van is full. There’s no more room to keep any more criminals so the police can no longer do their job unless they empty the van by getting everyone back to the police cells.

It’s a similar story with the filter and separator in your compressed air system. The filter grabs the rogue oil in your system, but without anywhere to go that filter would quickly clog up and be unable to perform its task efficiently.

The separator is the police cell of the operation. It traps the oil within the system so the filter can keep doing its job.

Protect product quality

If it isn’t filtered and then separated from your air compressor, some oil can combine with water vapour to coat and contaminate not just the area around the compressor but the products you’re using the air power to create.

It may not matter greatly that a little oil vapour finds its way into an air drill or tyre inflator. But for anything the requires precision or a pristine finish, it certainly will.

To meet regulations

Without a separator, the bulk of the oil will condense and collect with the moisture within the system. But Condensate Drainage Regulations state that it’s against the law to pour polluted wastewater into drains. If you do, you could face a fine of up to £20,000. And that’s nothing compared to the potential reputational damage.

Algar Air supplies the oil/water separators that ensure your compressed air system produces only clean waste.

Our separators are available to buy independently as one-off purchases, or as part of a comprehensive compressed air installation package.

Talk to our expert engineers about the right separator for your business on 0114 243 2347 or

Algar Air

Your pressure is our priority