Air Compressor Parts - Samco

A Guide to Air Compressor Parts 

Air and commercial compressors are actually pretty heavy-duty. Not only do they have to run constantly, but they must do so under extremely high pressures. The tolerances required and the interaction between each component are key to working efficiently. Today we will talk you through all of the components in our guide to air compressor parts. 

How an Air Compressor Works 

Air compressors are used in a wide variety of applications. While you may think they are limited to industrial settings, such as car workshops and factories, you’ll also see them feature elsewhere in uses such as for painting and decorating, in pressure washers, and in heating and ventilation systems. 

See how they work.

Air compressors work in a similar way to a car’s combustion engine. A piston moves up and down in a cylinder, compressing the air. This happens in a cycle: 

Stage 1 – Intake 

Like in a car, the piston starts at the top of the cylinder and is moved down by an actuator connected to an electrically driven motor (via a belt). As the piston travels down the cylinder, it pulls air in through an intake valve.  

This works in exactly the same way as drawing a plunger on a syringe. 

Stage 2 – Compression 

Once the cylinder reaches the bottom, the intake valve closes, and the cylinder is forced up by the actuator. The air within the cylinder is heavily compressed and rises in temperature. 

Stage 3 – Discharge 

At a predetermined pressure, a discharge valve opens. This allows the compressed air to flow into a tank. The tank will have an automatic safety valve limiting the maximum pressure that can be reached inside.  

You may notice that while you have an air compressor running, occasionally, you’ll hear a tick or rhythmic hiss. The tank reaches its maximum pressure and prevents further air from being introduced. 

Air Compressor Parts: A Complete List 

While simple, the above guide should give you a good understanding of how air compressors work. The process relies on the interaction of several components. All of which you will find below. 

  1. Actuators 

If the concept or term actuator seems unfamiliar, allow us to put it into simple terms. In the most basic sense, an actuator is something that instigates a movement in a piece of machinery. There are many types of actuators, and these can vary depending on the type of compressor you have. Normally, piston-driven air compressors use linear actuators (creating the up and down movement of the piston). 

  2. Belts 

Belts are what connect your air compressor to the means of propulsion. The electric motor will drive the compressor using the belt. Belts are very much perishable parts. They degrade over time and can become damaged or worn.  

Belt tension is also important. If the belt slips, this can cause a loss of power and efficiency. If it breaks completely, it can also cause damage.  

  3. Crankcase 

The crankcase is the housing for the pistons and crankshaft (the arm that drives the piston). Crankcases need to be well maintained and must be of high quality. When the piston travels up the cylinder, there is an immense pressure buildup. Any flaws or imperfections will cause the compressor to fail. 

  4. Seals and Gaskets 

Compressed air is not something that is very easily contained. When operating under pressure, and to prevent air from escaping, you will need a tight seal. You’ll tend to find seals or gaskets wherever there is a join between two components, but also where there are moving parts. 

These seals perform two purposes. First, they prevent compressed air from escaping, but they also prevent contaminants from the outside world from entering the system too. A blown seal can be dangerous. 

  5. Gauges 

How will you tell that your compressor is operating at peak efficiency or has the desired pressure in the tank? The answer is by having a working and reliable gauge.  

Aside from ensuring normal operation, gauges can be great for spotting problems before something more serious develops. A consistent loss or failure to achieve adequate pressure could signify that a component has failed elsewhere. 

  6. O-Rings 

O rings are parts that are relatively easy to replace. Normally they resemble small, circular bands that are used in components that are screwed together. As the screws, bolts, or edges meet, they compress the o-ring, causing it to spread and ensure a really tight seal. 

  7. Piston Rings 

Piston rings are a little special. These line the piston heads to ensure a completely tight seal with the crankcase walls. Considering how fast these pistons move in reality and how much pressure is placed on the cylinder with each stroke, it is easy to see how vital it is that they are well maintained.  

Along with piston rings, you also have to consider lubrication. Adding the right lubricating fluids to your system will ensure the longevity of your rings. 

  8. Valves 

Without correctly working valves, the entire system will break down. With pressurization, timing is everything. If valves don’t provide a good seal and close their side of the system when they should, a compressor simply isn’t going to function.  

Valves are one of those components which fail most regularly in compressor systems. They require constant servicing and attention. Be sure to choose valves that offer the highest degree of efficiency and lifespan. 

  9. Oil Filter 

All mechanical systems need lubrication. It is their lifeblood. If oil becomes dirty, especially with fragments or metal swarf, this can wreak havoc with your compressor and significantly shorten its useful life. Be sure to check your oil filter regularly for signs of wear within the compressor.  


Samco Enterprises offers parts and maintenance for compressors and much more. With a range of components for compressors and detailed knowledge spanning 40 years, we are in the best possible place to meet your needs. We specialize in compressor valves and kits for a range of applications. 

From industry standards like Ariel compressor parts to Dresser Rand compressor parts, we carry compressor parts you can trust and a service you can count on.