How to Use Your Air Compressor
Using an air compressor correctly is straightforward once you understand the basic setup, pressure controls and shutdown routine. This guide explains the process step by step so you can operate your compressor more confidently and safely.
Quick Answer
To use an air compressor, place it on a stable surface, check the oil level if required, connect the air hose, switch the compressor on, allow the receiver to fill, set the outlet pressure to suit your air tool and then connect the tool. When finished, switch the compressor off, release stored pressure as appropriate and drain moisture from the air receiver.
Before You Start
Before switching on any compressor, check the manufacturer's instructions supplied with your particular machine. Different compressors may have different operating requirements, especially when comparing direct-drive, belt-driven, oil-free, lubricated and rotary screw compressors.
- The compressor is positioned securely on a stable, level surface.
- The power supply is suitable for the compressor.
- The air hose and fittings are in good condition.
- The air receiver drain valve is closed.
- The oil level is correct if you are using an oil-lubricated compressor.
- Any guards, covers and safety devices are correctly fitted.
How to Use an Air Compressor Step by Step
1. Position the Compressor Correctly
Place the compressor on a firm, level surface with enough space around it for ventilation. Avoid blocking cooling vents or positioning the machine where it could easily be knocked over, exposed to excessive dust or come into contact with water.
2. Check the Oil Level if Required
If your compressor is oil-lubricated, check the sight glass or dipstick before use. The compressor should contain the correct type and quantity of oil recommended by the manufacturer. Oil-free compressors do not require this step.
3. Connect the Air Hose
Connect your air hose securely to the compressor outlet. Make sure the coupling is fully engaged and that the hose is suitable for the pressure produced by the compressor.
4. Connect the Compressor to the Power Supply
Connect the compressor to the correct electrical supply. Many smaller compressors operate from a standard single-phase supply, while larger workshop and industrial compressors may require a dedicated electrical connection.
5. Switch the Compressor On
Turn the compressor on and allow it to build pressure. On receiver-mounted compressors, the motor will normally stop automatically when the receiver reaches its preset maximum pressure.
6. Set the Outlet Pressure
Use the pressure regulator to adjust the outlet pressure to suit the air tool or equipment you are using. Do not simply run every tool at the compressor's maximum pressure.
7. Connect Your Air Tool
Once the outlet pressure has been set correctly, connect the air tool using the appropriate quick-release coupling. Check the connection is secure before operating the tool.
8. Use the Tool Normally
Operate the air tool according to its own instructions. The compressor will cycle on and off as required to maintain pressure in the receiver.
Understanding the Two Pressure Gauges
Many receiver-mounted air compressors have two pressure gauges, and these can be confusing if you have not used a compressor before.
Receiver Pressure
This shows the pressure currently stored inside the air receiver.
Outlet Pressure
This shows the regulated pressure being supplied to your hose and air tool.
What Pressure Should I Set My Compressor To?
The correct pressure depends on the air tool or equipment you are using. Always check the tool manufacturer's recommended operating pressure.
Many workshop air tools operate somewhere around the commonly used workshop pressure range, but you should never assume that every tool requires the same setting.
Make Sure Your Compressor Has Enough Airflow
Pressure is only part of the equation. Your compressor must also supply enough airflow for the tool you are using.
Airflow is commonly measured in CFM or litres per minute. Tools such as spray guns, sanders and grinders can consume significantly more air than smaller tools such as blow guns or tyre inflators.
If your air tool uses air faster than the compressor can produce it, receiver pressure will gradually fall and the tool may lose performance.
How to Shut Down Your Air Compressor
When you have finished using the compressor, follow a sensible shutdown routine.
- Stop using the connected air tool.
- Switch the compressor off using its normal on/off control.
- Disconnect the power supply if appropriate.
- Release pressure from the airline before disconnecting tools or hoses.
- Drain accumulated moisture from the air receiver.
Why You Should Drain the Air Receiver
Compressing atmospheric air naturally produces condensation. Over time, water can collect inside the receiver.
Regularly draining this moisture helps protect the receiver and reduces the amount of water entering downstream air lines and equipment.
Do I Need an Air Dryer or Filter?
That depends on what you are using the compressed air for.
Basic workshop applications may only require simple moisture separation and filtration, while applications such as painting, CNC machinery, instrumentation or manufacturing processes may require significantly cleaner and drier air.
For higher-quality applications, a compressed air system may include:
- Water separators
- Compressed air filters
- Refrigerated air dryers
- Oil-removal filtration
- Condensate management equipment
Common Mistakes to Avoid
Always set the regulator according to the tool's specified operating pressure.
A compressor can provide the right pressure but still be too small for a high-air-demand tool.
Condensation can accumulate inside receiver-mounted compressors during normal use.
Inspect airline components regularly and replace damaged parts before use.
Air Compressor Safety Tips
- Never exceed the rated pressure of the compressor, hose, fittings or connected equipment.
- Never direct compressed air at yourself or another person.
- Wear appropriate eye, hearing and task-specific protective equipment.
- Keep compressor ventilation openings clear.
- Do not modify pressure switches or safety valves.
- Use suitable hoses and fittings rated for compressed air.
- Follow the manufacturer's maintenance schedule.
- Have faults investigated rather than repeatedly resetting or overriding safety devices.
Frequently Asked Questions
Do I need to let an air compressor warm up?
For most normal workshop compressors, you should follow the startup instructions provided by the manufacturer. Larger industrial compressors may have different startup procedures.
Can I leave my compressor pressurised overnight?
Follow the manufacturer's recommendations and your site's procedures. For many portable and workshop compressors, users commonly isolate the machine when it is not required and drain accumulated condensate regularly.
Why does my compressor keep switching on and off?
Receiver-mounted compressors normally cycle automatically. The motor stops when the receiver reaches its upper pressure setting and restarts when pressure falls to the lower setting.
Why is water coming out of my airline?
Compressed air naturally creates condensate. If water is reaching your tools or process, you may need improved drainage, water separation, filtration or an air dryer.
How do I know what size compressor I need?
Start by checking the required airflow and pressure of the tools or equipment you plan to run. Allow suitable spare capacity rather than selecting a compressor that only just meets the theoretical requirement.
Need Help Choosing or Using an Air Compressor?
If you are unsure about compressor size, airflow, pressure, filtration, air treatment or the right equipment for your application, the Tanair team can help.
Ask Our Team