how to regulate air pressure on an air compressor
Tips & Tricks

How to Adjust an Air Compressor Pressure Regulator

One of the essential parts of an air compressor is the air regulator. It is pretty much the only part of your compressor you need to master to get the most out of it. Granted, you still need to learn how to use the pump and the receiver, but without knowing how to adjust, cut in, and cut out pressure, owning an air compressor is pointless.

What does a regulator do on a compressor?

An air regulator is a pneumatic device that takes in air at any pressure within its range and releases it at a lower rate than a predetermined pressure. In layman’s terms, an air regulator takes in air at a higher pressure and releases it at a lower pressure. The air intake is commonly known as upstream, while air is released in known as downstream.

The pressure regulator pushes incoming air using a system of springs and an internal diaphragm to ensure only a set volume of air is released. Air pressure is calculated by volume in a given surface area. The regulator offers the necessary resistance to ensure the set air pressure is not exceeded.

For the air pressure to remain constant, the upstream air has enough pressure to open the diaphragm. But not too strong that it tears the air regulator off the air compressor. Without an air pressure regulator, too much air pressure may damage the air compressor, anything you plug into it with the wrong pressure & CFM or affect the quality of the job is done.

The pressure regulator also plays an instrumental role in creating a cutting-off point if the air compressor needs to turn off automatically. The air regulator will cause the upstream system to back up and buildup until it reaches the cutoff point causing the air compressor to shut down and stop taking in more air.

What PSI should my pressure tank be?

This depends on the type of tools you are going to be powering with your air compressor. Most air tools require 0-5 cubic feet per minute of air at 70-90 pounds per square inch (psi). And large devices require ten cubic feet per minute at 100-120 psi.

If you use your tank daily, you can leave it pressurized at the PSI suited to your next day’s job. You have to drain the water, and you should not leave it plugged. However, you must empty your pressure tank if you do not wish to use it in the near future. Drain the tank while at it to mitigate moisture and water damage. 

Why isn’t my air regulator working?

Damaged diaphragm

Due to the pressure in the air pressure tank, the diaphragm will end up cracking over time. It may also get damaged by oils leaking from the compressor. Debris in the upstream air can also damage the diaphragm and drying out of the diaphragm due to inactivity.

Corroded parts

Air condensation, oils, and other volatile compounds may corrode some of the air regulator parts, causing it not to work correctly. Additionally, pressure from the air pressure tank may cause the air regulator to crack.

How to Adjust an Air Compressor Pressure Regulator

While the method for adjusting the air pressure in your compressor may differ slightly from model to model, the air regulators pretty much work all the same. However, this may be a bit of a challenge if you are new to using air compressors. Here are the necessary steps for adjusting an air regulator;

How to increase the air pressure

Ensure your air compressor is unplugged from the power outlet before you begin this undertaking. Then proceed to set the cut-in pressure and the cut-out pressure. Refer to your manual to locate the screw for setting the cut-in pressure. In most compressors, it is found near the motor. Then plug in your air compressor into the electric outlet.

To ensure your new pressure is set as desired, drain the pressure tank. When the pressure tank is filled, connect the hose to the air tool you intend to use. Turn the air regulator screw clockwise to increase the air pressure.

How to reduce air pressure

Follow the steps above to set cut in and cut out pressure, and when the pressure tank is filled, turn the screw anti-clockwise. The pressure range between the cut-in and the cut-out pressure should always be between 20-40 psi. And the cut-out pressure should always be higher than the cut-in pressure.

The regulator know is usually found on the right-hand side of the air compressor in most models. Most air regulator knobs have a locking feature. Remember to pull it out to unlock and push it in to lock it once you set your desired pressure.

Air compressor regulator troubleshooting

Without an air compressor regulator, you will not control the air pressure, meaning you cannot use it with multiple air tools. As such, you must know how to troubleshoot your regulator should it stop working. Here are the main ways to troubleshoot your air regulator;

Check for pressure

Look at the air regulator gauge to see if the readings are accurate. If you notice a lower reading or no change in the air pressure, yet the pressure tank has air, something is wrong with your air regulator.

To ensure your findings are correct, drain the pressure tank and refill it, then check to see if you will still get a zero reading. Ensure that the coupler-joint at the air regulator and the air regulator’s screw-in flange are functioning correctly – to eliminate them as the cause of the incorrect air pressure readings.

Inspect the air regulator

Ensure your air regulator has been set to the correct pressure as per the manual. Refer to the operating manual to confirm if the knob has been set to the right pressure. If the setting mark is okay, then this means that the air regulator is faulty.

Inspect other air compressor components

Next, you need to ensure no air leaks in the pressure hose supplying air to the air regulator. This can cause the air regulator to give a faulty lead. If this is the issue, then replace the hose. Once you have replaced the defective hose and inspect the air regulator again to ensure it is working correctly. You should also check the quick release coupler near the air regulator to ensure it is not faulty.

Once you have ensured all other components that work with the air regulator are okay and are still not working, you need to replace the air regulator. Ensure that you get one that is compatible with your air compressor brand and model.