Air Supply UK: Specialist Compressed Air Engineers

Published: 28/03/2024

The ultimate guide on how to use an air compressor

Air compressors can power a wide range of pneumatic tools, making them essential machines for many DIY enthusiasts. Although using a compressor is beginner-friendly, you should still ensure that you clearly understand how to set up, operate, and switch off your compressor before you start. 

The air compressor experts at Air Supply have put together this ultimate guide, which includes the eleven steps to using an air compressor safely. 

1. Safety

Before you start setting up your air compressor, it’s important to wear appropriate safety gear (PPE), such as safety boots, ear defenders and polycarbonate goggles to protect your eyes. It’s also a good idea to avoid loose clothing, which might become entangled in the compressor. 

2. Insert oil into the compressor

If your compressor uses oil, you must add oil before operating the machine. Older or larger compressors tend to be oil-filled, while many small, new models are oil-free. If you’re unsure whether your compressor needs oil or what type you have, it’s best to consult the owner’s manual. 

You’ll need to check the pump oil level by removing the oil cap and locating the dipstick near the bottom of one of the compressor’s ends. The oil level should reach approximately two-thirds of the way up the stick. If it doesn’t, you must top up the compressor oil. 

3. Plug in the compressor

Ensure the compressor’s power switch is set to ‘OFF’ before connecting the power cord to the machine. Plug the compressor into a grounded outlet. You should avoid using extension cords as these might cause the machine to overheat.

4. Connect the air tool hose assembly 

First, you’ll need to plug in the air tool hose. Attach the hose to the regulator valve (the copper-coloured metal plug with a hole in it), which is usually found next to the smaller pressure gauge on one end of the compressor. Push the pointed end of the air tool hose into the valve to attach it.

You can then plug your air tool into the hose by sliding the tool’s plug into the free end of the hose. Twist them together until the tools lock in place securely. 

5. Test the safety valve 

Ensure the compressor is off and depressurised. Then, locate the safety valve. This is usually a small valve with a ring or lever on top located on the air tank. 

Pull the lever or ring and release the valve to test the safety valve. If there’s any residual pressure left in the tank, you’ll hear airflow escape. The valve should snap back into position. If it doesn’t, this is a sign that it might be faulty. 

6. Turn on the compressor 

Turn on the compressor and wait for the tank to pressurise. You should see the pressure rising on the larger pressure gauge on the tank’s side. Wait until the needle stops moving, indicating that the tank has reached the maximum pressure. 

You might also notice a second smaller pressure gauge near the hose. This displays the hose pressure and might not move while the tank pressurises.

7. Set the pressure regulator

Check the pneumatic tool you plan to use to see how much air pressure it requires. You can usually find this printed on the tools, in the owner’s manual or online. It will state the maximum PSI at which the tool can function. Twist the pressure regulator knob clockwise to increase the pressure or twist it counterclockwise to lower the pressure.  

When using the tool, ensure the hose pressure remains slightly below the maximum. For example, if the tools function at a maximum of 100 PSI, you should keep the hose pressure between 85 and 95 PSI. 

Many tools have different maximum pressures, so you’ll need to check if you need to adjust the pressure when switching tools. 

8. Operate the power tool

Once you’ve set the correct pressure and the pressurised air is in the hose, you’re ready to operate your pneumatic tool. Every time you use the tool, the tank pressure drops and the refilling automatically begins. 

If the tool suddenly stops working, this might be because the tank is too small to accommodate the tool and is struggling to refill the tank fast enough. You’ll need to wait a few moments for the pressure to increase before you can continue using the tool. 

9. Open the air tank drain valve to let out condensation. 

After you finish using the compressor, you’ll need to open the air tank drain valve to release the condensation. This is usually found on the underside of the air tank. Twist the valve counterclockwise so the pressured air blows out the moisture. Ensure you put the valve back in black and twist it clockwise until you don’t hear any more air escaping. 

It’s recommended that condensation is drained after every use to keep your compressor working efficiently. 

10. Turn off the compressor to drain the pressure. 

Leave the hose in place when the compressor is turned off. First, twist the pressure regulator knob to shut off the air supply to the hose. Then, turn off the compressor and wait for it to depressurise. You can open the pressure relief valve to speed up this process.

11. Store the compressor 

Finally, remove the hose to store the compressor. Unplug the compressor, remove the hose and store both in a dry environment. 

How Air Supply can help

At Air Supply, we have decades of experience selling, servicing, and repairing a huge range of compressed air treatment equipment. We also offer used and new air compressors at competitive prices and used machines available for hire. So, if you’re looking to buy a compressor for the first time, our site should be the first place you check! 

Our expert team also provides comprehensive maintenance, servicing, and repair services. Whether your compressor is not working efficiently or has a more serious problem, our compressor experts can get it up and running as it should as soon as possible. 

Contact us today to learn more about our products and services, or speak to a member of our team if you have any questions. 


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