Why you MUST drain your dental compressor and how to do it.

Another very useful dental equipment maintenance tip from Presid | Saturday, 01 April 2017


Dental compressors are one of the most important pieces of equipment in your dental practice. Without any compressed air you will be extremely limited as to the operations you can perform. Without compressed air your handpieces will not work or your micromotors will overheat, your spittoon valve probably will not work meaning that you have no drainage from your spittoon and it is quite likely that your chair will not work as most of them use air switches to enable the movement, no aspirating syringe and due to aforementioned air sitches, no suction either.

Most compressors are stuffed away out of sight (and probably out of mind) in a shed, store room or basement cupboard and tend to be neglected unless your dental equipment professional reminds you of a service due or it breaks down. Considering the fact that this unit will spray air almost directly into a patients' mouth it should be a priority for your practice to maintain and service your compressor to avoid breakdown, significant loss of revenue or even worse.. infection of your patients.

This blog is not about regulations such as HTM 2022/1, the European pharmacopeia directive, EN737-3, NHS or COSHH guidelines it is about what happens when you do not DRAIN your compressor.

A dew point is a temperature below which water in compressed air will condense and form onto a solid surface. The temperature inside your compressed air chamber will dictate how much water will condense and collect inside the chamber, to this end compressor chambers have a drain mechanism to expel this condensation.. failure to drain the compressor will literally mean that the chamber will FILL up with water which will create the following problems:

Water is by and large incompressible unless you have a massive amount of pressure available and even the the next compressed state is ice, water will take up space in the chamber which effectively reduces the size of the chamber, as you use the compressed air available it will force the motor to run more often as it has a smaller chamber to 'charge up' with air and will significantly reduce the life of your compressor motor.

 More water means more medium for bacteria to grow and worse case scenario is your compressor will pump dirty water directly into a patient.

Ok.. do we have your attention?

There are generally two ways to drain a compressor chamber, manually or automatically. Automatic drainage devices are relatively easy to retrofit to your existing compressor but we personally would opt for the manual version as we then know without a doubt that it is being done. On the compressor CHAMBER invariably there will be some kind of tap such as these:

Turn the compressor off, only because if it starts up while your face is near it it will scare the life out of you!

Starting from the BOTTOM of the chamber (the big round bit) work upwards until you find a tap or valve. These are placed on or very near the bottom because the air pressure inside the chamber will try and escape outside but it has to push the water out first and water collects at the bottom!

Turn the tap SLOWLY.. no.. S L O W L Y  or you could get very wet! Open the valve just enough to let water out not decorate the wall behind you. If your compressor is not oil free then this water could be very dirty and oily, collect it in a suitable container with a lid and dispose of responsibly for example a dedicated section of your local refuse amenity or 'tip'.

We have seen 20 litre compressor chambers almost completely full so you need to make this draining procedure a part of your daily or weekly maintenance program or you may struggle to find a container big enough to take all of the water, even if you have an automated drain fitted you still need to remember to empty the collection bottle regularly.

Our next blog will refer to in more detail the current regulations and demystify the general understanding of oil / oil free compressors. Until then.