About Air Compressor Parts

This section provides general information regarding common air compressor parts. Below you will find the basic operation and importance of items such as check valves, filters, etc...

If you are looking for more detailed information regarding a specific part, or need help in deciding what part will best fit your compressor, browse our FAQ and air compressor troubleshooting section.

Check Valve

An air compressor check valve is a device that allows fluid or air to flow in only one direction. When your compressor reaches the unload pressure, the check valves closes to prevent backflow of the air from the tank to the compressor head.

air compressor check-valve

A quick note on check valves: Many times people will find air leaking from the pressure switch. When this occurs, they immediately purchase and install a new pressure switch. Because air still leaks, they call and state that the switch is defective.

If air is leaking consistently, the problem is not the pressure switch - it is the check valve. More than likely it is filled with debris and is not sealing. When this occurs the check valve either needs to be cleaned or replaced.

Pressure Relief Valve / Safety Valve

Any place that you would have high pressure, you will also need a pressure relief valve (also known as a safety valve). A pressure relief valve releases air smoothly and consistently into the atmosphere from the compressor tank if the air pressure becomes too much.

Generally a relief valve will have male threads on one end, with a ring on the other end (as displayed in the photo). By pulling the ring, you are releasing compressed air into the atmosphere in a safe manner. It is pretty rare that you will ever have to use a PRV, but it is necessary to ensure safety.

Safety valve / pressure relief valve

Pressure Switches

An air compressor pressure switch is an instrument which senses a change in pressure and automatically adds or decreases air in the tank. Most homeowners simply know the pressure switch as the device that contains the on/off lever.

Air compressor pressure switch

Certain air compressors have specific pressure switches that are designed specifically for the machine. Campbell Hausfeld is one company that makes uses a specific switch for each of their compressors. The CW301300AJ kit is by far the most popular.

There are also more generic pressure switches that vary depending on what your cut-in and cut-out pressure is. The photo to the right displays a typical pressure switch that is common on many homeowner style compressors. The small red piece at the top is the on/off switch for the machine.


Depending on the type of compressor you have, an air compressor belt is an essential component of your machine. Most homeowner and smaller hand carry compressors do not use a belt. When you get involved with wheelbarrow or stationary compressors, belts become necessary (especially with virtually all Ingersoll Rand air compressors). A belt works with the pump to help spin the motor to the correct horse power.

Sizes and styles vary across the board. Everything from grooves, length, and width will change depending on the type of compressor that you have. To help find the correct belt for your compressor, we recommend finding you model number and giving us a call.

Air Gauges

Generally, most air compressors come complete with two pressure gauges. Most will have one gauge near the pressure switch to display the pressure setting, and another gauge to indicate the air pressure in the tank.

Although an air gauge may not seem like an extremely important part - it is. Having a broken or non functioning gauge means that you will not know the pressure setting at your application, which can result in the incorrect use of your tools.

When you replace an air gauge, make sure you know whether you have back mount or bottom mount threads, and your desired pressure range.

Back mount compressor gauge
Example of a back mount gauge
Bottom mount compressor gauge
Example of a bottom mount gauge

Unloader Valve

Simply put, the unloader valve unloads air when the receiver reaches its set point. Most of the time an unloader valve is located at or near the pressure switch, and when the switch is turned either on or off, the unloader valve is either opened or closed.

There are many different varieties of unloaders available. They will vary by the type of compressor as well as the manufacturer. By giving us a call at 1-866-208-2797, we can generally let you know what type of valve is necessary.

Air Filters

There are numerous varieties of air filters that may be used on a compressor. In-line filters and inlet filters however are the most common.

Intake filters are pretty much self explanatory. They filter the air for the first time as it is brought into the system. These are very important to your compressor system, and the operator needs to ensure that they are clean and free from debris.

In-line filters are placed throughout the piping system to ensure that clean air is reaching the end product. It is pretty rare for homeowners and people with small consumer grade compressors to use an in-line filter. In industrial applications they become much more common. Using an in-line filter will make sure that the end line is free from particles and debris, which will ensure that your compressor tools and attachments will last for many years to come.

Inlet air filter
SS1/SS3 Inlet Filter
Inline air piping filter
Inline air filter

Auto Drains

Generally this will only apply if you have an industrial or stationary compressor. Homeowner and small contractor compressors do not have auto-drains available, as they are all manual drains. There is a drain on the bottom of the compressor, which should be opened every two days at a minimum (generally once a day is a good idea). this drain helps to remove any water from the compressor tank. If water is left for long periods of time, rust will start to accumulate in the tank.

An auto drain eliminates the need to manually drain the tank every day. It is equipped with a timer that automatically opens the drain at a set time each day. Lets face it, people can forget and mistakes can be made. Therefore, an auto drain is almost always recommended for applications that require consistent air. It makes life easier and helps to prevent mishaps from occurring.

EDV 2000 auto drain valve
The EDV-2000 is one of our most popular auto drain valves.

Gaskets/Gasket Kits

There are various types of gaskets that are used on compressors depending on what type of compressor that you have. Industrial compressors may have head gaskets, cylinder gaskets, etc, while homeowner compressors may use none at all. These gaskets help create a seal when two items are placed together, such as sealing the cylinder head to the valve plate assembly. Many times these are all combined together in one gasket kit.

Each type of gasket will vary depending on the model and manufacturer of the compressor that you have. One of the best resources that you can find with the correct gasket that you need would be the owners manual of your compressor. Of course, you can always call 1-866-208-2797 with your serial and model number, and we can find the correct part for your compressor.

Vibration Pads

Vibration pads are pretty self explanatory and simple. These pads are small pieces that are made out of various materials (often cork), which are placed under each foot on the air compressor. They are then screwed into the ground with the air compressor, and helps to reduce the amount of vibration and rattling that occurs. It reduces the amount of contact that the compressor has with the ground, and depending on the surface it will reduce noise and lengthen the compressor's life.

Vibration pads reduce damage to a compressor
Air Compressor Vibration Pads