If your air compressor has been put to work for a long time, it is essential for you to know how to drain an air compressor. A water-filler air compressor can slow down productivity and add more other related issues.

That’s why it is extremely crucial for you to understand the situation and most importantly, know how to get rid of humidity out of your air compressor.

In this article, we will present you a step-to-step guide on how to drain your air compressor properly, along with knowledge on when to know that your air compressor needs draining, and some frequently asked questions regarding this problem.

And now, keep on reading for a better air compressor life!

When To Drain An Air Compressor?

Where Does The Water Come From?

Where Does The Water Come FromIn your air compressor, condensed water is most likely to be created due to the low temperature of the air compressor, there is also the phenomenon of water compressor.

The fact that there are some regions located in the tropical humid climate proceeds to the event where the air compressor contains a lot of water vapor. During operation, when the suction valve unit is open, the airflow will enter and the air will be fed into the compressor head assembly. In the compressor compartment part, the oil and gas components are mixed together (of course, the air also includes the moisture of steam).

After this process, the oil and gas mixture is passed through the cooling tank section or directly to the oil tank section in order to separate the oil from the compressed air. At this time, a lot of water will be deposited at the bottom of the compressor oil tank.

In this case, if the temperature of the oil is low (usually will be lower than 60 ° C) then there will be insufficient temperature to ensure complete evaporation of the water. Because of this, water will collect in the oil tank and all oil recirculation components in the air compressor.

The fact that water vapor in the air will be put into compressed air is something neglectable. What we need to consider is how to minimize the issue of water existing in the tank of the air compressor.

Implied Signs For A Drained Air Compressor

Implied Signs For A Drained Air Compressor

  • Discharge a considerable amount of oil or look through the oil level indicator glass in flesh. The affected oil will be lighter than the original.
  • An abnormal increase in the oil level reported through the oil indicator glass detected.
  • At the bottom of the tank, through the oil gauge of the air compressor, standing water might be detected.

How To Drain An Air Compressor?

How To Drain An Air Compressor?The condensation problem in your air compressor is not something that you can turn a blind eye to. How to resolve this issue, you may wonder?

Here’s how you can get rid of the humidity existing in your air compressor. Make sure you follow these guided steps below in a careful way.

  • Step 1
    First thing first, you must guarantee to have your air compressor switched off. Rather than just simply turn off the device, we need you to unplug to transform the compressor to the initial state. This action should be executed in order to maintain your labor safety.
  • Step 2
    Reposition your air compressor to where it is situated slightly inclined. This will make the drain valve the lowest point and it will prove to be beneficial in getting out all the dirt, debris, moisture or anything that comes afterward.
  • Step 3
    Next step is reducing the current air compressor’s pressure down to somewhere below 10 PSI. This is to prevent massively strong outcomes from the drain valve which could put you in hazard. Locate the ring on the tank’s safety valve and pull it out to release the pressure.

    Protecting goggles are recommended from this step later on to prevent uncontrolled flying debris crashing into your eyes.

  • Step 4
    Look for the drain valve normally located somewhere on the bottom of the tank (usually marked with words).

    Slowly open the drain valve counter-clockwise to release the internal liquid. As you rotate the valve, more and more debris will come out, that is why this action should be carried slowly and carefully until no more mukey water is detected.

    When you have sure that the tank is fully drained, feel free to close the valve by rotation clockwise and put your air compressor into use once again.

Frequently Asked Questions

Frequently Asked Questions

What Can Go Wrong With Condensation In An Air Compressor?

Unsolved moisture in the tank can jeopardize the effectiveness of operation, making the compressing process slower and less efficient.

If you don’t drain the compressor on a regular basis, rust will form inside the tank which can weaken the walls and could be hazardous for the whole compressing system.

Due to the untreated moisture, the lifespan of the air compressor can be considerably degraded due to lowered quality which requires costly maintenance.

How Often Should I Drain An Air Compressor?

In case your air compressor is put into work daily, make sure to drain the tank every 2-3 days. There is no such need to spend time draining it every single day after usage. If you decide to drain the compressor every given day, make sure to put it in great maintenance.

Nevertheless, if you only use your air compressor a couple of times per year, it is best to drain the tank after every use.

Can I Use An Automatic Air Compressor Draining Device?

Automatic tank drain is best recommended in industrial application situations where your air compressor takes a considerable time to manually water-drain. However, if your air compressor is not as described, you can still purchase an automatic tank drain.

An automatic tank drain helps excessive condensation to escape in every burst of compressed air rather than the manual method of draining down. However, it cost a budget to be lazy.


Your compressing tank will work and maintain in the best condition if you have mastered the proper way to drain an air compressor. Remember, never let yourself be lazy to not get rid of excess water in the compressor tank, unless you want it to soon break down.

We hope that this guide on how to drain an air compressor will come in handy for you. See you next time!