Air compressors have brought a lot of comfort and ease to our lives. Over the years, they have evolved significantly and playing more integral and beneficial roles in domestic and industrial industries.
There are various types of air compressors, but the actual task of all these types of air compressors is to convert energy into compressed air. On the basis of operating principle, there are three types of air compressors, i.e. reciprocating air compressor, rotatory screw air compressor, and rotary centrifugal air compressor. To make it easier for you to understand, this resourceful blog aims to discuss the single-stage vs. two-stage air compressors!
Apart from their appearance, you can differentiate them on the basis of their work, compression stages, cooling method, drive method, and lubrication method. Among the three types of air compressors, the reciprocating air compressor is the most commonly used type that has many applications. The innovation level and efficiency of these air compressors are much higher than the rest of the two types. That’s why we will explore it in detail.
Reciprocating Air Compressors
They are also known as piston-cylinder air compressors as pistons are used inside them to compress the air. The front and back movement of something is known as the reciprocating movement. The same movement is used in reciprocating air compressors in which pistons move forth and back and compress air.
The entire process depends on two valves, i.e. intake valve and exhaust valve. Air enters the air compressor from the intake valve that is then compressed in a downward direction. It reduces the volume of the air. In the next step, the piston moves upwards and displaces the compressed air through the exhaust valve. This cycle repeats over again. This process is also known as positive displacement mechanics.
Don’t confuse between the oil-less and oil-free air compressors as both types have the same mechanism. Reciprocating air compressors are further divided into two categories, i.e. single-stage and double-stage air compressors. Before going into the details of both types, let’s discuss the major components used in the positive displacement mechanism.
The structure of the air compressor is enclosed in the frame of the air compressor. It protects the internal parts of the air compressors and prevents them from getting damaged. The rectangle-shaped frame is also known as a crankcase that supports the crankshaft.
This is one of the most important parts of an air compressor that performs the principal part. There can be one or two pistons in the air compressors which compress the air and moves energy from the crankcase to the gas contained in the cylinder. Usually, aluminum or cast iron is used in the construction of the pistons.
Cylinders store air. The pressure level of an air compressor depends on cylinders. They are connected to the frame with the help of the distance piece. The functionality of the intake valve and pistons depends on cylinders. So, if they get damaged, you should replace them quickly.
The distance piece is placed between the cylinder and the frame. The main purpose of this part is to separate both components. It is usually divided into two categories, i.e. a single design and double design while the classification of the distance piece can be done into Type A, Type B, Type C, and Type D. The purpose of the distance piece is to prevent the entrance of any external component in the air compressor.
Both single-stage and two-stage air compressors have piston rings. They are attached to the piston and once the piston moves up and down, they also move and contact the walls of the air compressor. Regular lubrication is mandatory for these piston rings or the wall of the piston is damaged due to the high friction level. Metallic or non-metallic rings are used in the air compressor. Fluorocarbon is used in the manufacturing of non-metallic rings while bronze or cast iron is used in metallic piston rings.
Two shafts are used in the working of the air compressor. The bigger shaft is known as the crankshaft while the smaller one is called the motor shaft. It’s responsible for moving the connecting rod, piston rod, and piston. This shaft moves the piston in the upward and downward direction and ensures the proper working of the piston.
The other parts of the air compressor include bearings, valves, and a cross-head. Their functions and simple and self-explanatory.
Single Stage Vs. Two-Stage Air Compressors – All You Need To Know!
The working principle of both types of air compressors is the same. The major difference is the number of times the air gets compressed between the inlet valve and the tool nozzle. However, their applications, benefits, and drawbacks are different. Let’s make a comparison between both types to understand the major differences.
Single Stage Air Compressor
The single stage air compressor is also known as a piston air compressor that can compress air up to 120 psi. They are sued for pneumatic devices which need an air pressure of up to 100psi.
When the operation of the air compressor starts off, the piston compresses the air present in the cylinder. The piston ensures to compress the air so strongly that it generates a one-way connection between the cylinder and the receiving tank. A powerful air compressor will compress air at the maximum level. The more air will be compressed by the piston the higher would be the efficiency level of the air compressor.
Once the compressed air is released from the piston, it enters the receiving tank where the maximum pressure is achieved. This tank is connected to the pressure switch that continuously monitors the pressure level. Once the preset value is achieved, the motor of the air compressor turns off automatically and it turns on automatically when the PSI level drops below the preset value of PSI. More compressed air enters into the cylinder and the cycle goes on.
Benefits of Single Stage Air Compressor
- There are various benefits of a single-stage air compressor that makes it useful for different tasks. As the power of the air compressor is limited, the benefits and applications are also lesser as compared to the two-stage air compressor.
- It’s the best machine to deliver low air pressure. You can choose a compact air compressor that is easy to move from one place to another. Travel lovers can take it with them and make their journey safe as it allows them to inflate the car’s tire when the pressure level drops down.
- Single-stage air compressors are easily available in an oil-less form which means you don’t have to replace oil over again. This feature makes them budget-friendly and saves your money in the long term usage.
- The cleaning and maintenance of the air compressor is also an effortless task. As oil-less air compressors work without oil, you don’t have to worry about the jammed internal parts due to the accumulation of the oil. Moreover, the maintenance of the single-stage air compressors is also not a biog headache. They need minimum maintenance and lasts for many years.
- Small pneumatic devices run on low air pressure and a single-stage air compressor is the best option for you. Due to the lightweight, you can easily carry them and use them for domestic and DIY projects. The storage of these air compressors is quite easy as they don’t occupy more space due to the small size.
Drawbacks of Single-Stage Air Compressor
One of the major drawbacks of the single-stage air compressor is limited usage. It can provide 125 PSI which not enough for biggers applications. The friction level is also high in a single-stage air compressor while the higher pressure ratio is the major reason for leakage loss.
There is no effective way to eliminate extra heat from the air compressor that increases the temperature level of the air compressor. Excess temperature damages the cylinder head and burns oil that is necessary for the lubrication of the air compressor.
- There are various applications of a single-stage air compressor. The small size of these air compressors makes them very useful for small tasks. Their applications range from woodworking to the garage and backyard of the home.
- Woodworking tasks require a lot of effort and physical energy. Pneumatic devices reduce the requirement of energy and help you complete tasks with more convenience. They don’t only reduce physical exertion but also lets you complete tasks faster. A single-stage compressor can be used in different woodwork tasks including sawing, nailing, drilling, and sanding.
- Metalwork is another industry that is facilitated by the benefits of the air compressor. The single-stage air compressor has many uses in this industry. It helps to cut and mold the toughest metals and eliminates the need for a hammer that consumes a lot of energy. The other tasks you can do one-stage air compressor include shearing, grinding, riveting, and ratcheting.
- Food manufacturing and preparation is another important industry where the need for air compressors is indispensable. Both single-stage and dual-stage air compressors are used in it depending on the magnitude and process of the task. Simple tasks can be done with the help of a single-stage air compressor. Mixing, cleaning, and nitrogen blower pumps need lesser energy and air pressure level and it can be done easily with the help of a single-stage air compressor.
Two Stage Air Compressor
The double-storage air compressor is the second type of reciprocating air compressor that is similar to the single-stage compressor with just one difference. Unlike the single-stage air compressor, compressed air never goes in the storage tank of the air compressor rather it goes another piston where the air is compressed further. Extensive tasks and machines which require 175 PSI pressure can use a double-stage air compressor.
In the two-stage air compressor, two pistons are used to compress the air. Air is compressed at low pressure in the first piston and then it’s sent to the second piston instead of sending it to the cylinder. The second piston compresses it further and the double compression divides the work between the two pistons and never overloads the single piston. It also helps you achieve a high-pressure level that is required in heavy industries.
Benefits of Double-Stage Air Compressor
- When we make a comparison between a single-stage vs. double-stage air compressor, there is a slight difference you find in the benefits of both air compressors. One of the biggest benefits of a double-stage air compressor is the high-pressure level you achieve which lets you do heavy-duty tasks effectively.
- The presence of two pistons lets you work for longer hours as both pistons divide work between each other and never exhaust easily. It works smoothly and never produces excess heat which keeps internal parts safe. The slow wear and tear of internal parts extend the lifespan of these parts and lets you enjoy their perks for decades.
- The design flexibility and uniform torque make it the best option for machines that require high torque and more pressure while the multi-stage compressor can be adjusted as per the compression requirements. It can also compress gases and refrigerants of high molecular density without any issue that proves it very useful in the liquid and gas industries.
- The low-cost life cycle proves it very useful for people who have budget constraints. Once you buy it, it lasts for years without disturbing the overall performance.
Drawbacks of Double-Stage Air Compressors
There are a few downsides to the dual-stage air compressor as well. They are bulky and heavy as they have to produce high power. However, the extensive weight makes them very difficult to carry and you even can’t move them from one place to another with ease. The absence of a portability feature also causes storage problems as keeping them on a car’s trunk or at home is a bit difficult.
It requires high maintenance and proper care. The heavy assembly of the dual-stage air compressor requires proper lubrication and regular oil change. If the oil isn’t replaced properly, then the chances of damage get higher. Oil attracts dust and the accumulation of dust and oil affect the performance and efficiency of the air compressor.
The comparison between the single-stage vs. two-stage air compressors is incomplete without mentioning their respective applications. They are designed to deliver high air pressure and capable of delivering 175 PSI air pressure.
- Auto assembly and maintenance is a big industry where the need for a two-stage air compressor is indispensable. The heavy-duty tasks are performed quite amazingly and they save a lot of energy and physical efforts. Lifting, screwing, greasing, and painting are some common tasks where dual-stage air compressors are used. Two-stage air compressors are also very useful for powering pneumatic air tools in the production and food packaging industry.
- The beverage industry needs to produce and package thousands of soda bottles every day. The bottles and food packages come in containers formed with air-powered equipment. Dual-stage air compressors are very useful in every stage of beverage products including molding, filling, sealing, labeling, and packaging. They are also being used in the food industry where packaged food and jars are prepared and packed.
- Military and aerospace is a big industry that needs pneumatic tools for multiple tasks. A two-stage air compressor plays a vital role in the cutting and molding of the heavy material. They help to shape the aluminum, steel, and iron into the required shape by offering extensive air pressure. The assembling, fasting, and finishing also require two-stage air compressors to be done effectively.
- Heavy metalwork and woodwork can’t be done smoothly without two-stage air compressors. It lets you cut and mold hard metals as well as provides enough power to pneumatic tools to drive multiple nails at a time in the wood. Shearing, grinding, and ratcheting are extensive tasks that consume a lot of human energy. However, the use of a two-stage air compressor reduces energy consumption and also saves your time.
Single-Stage Vs. Two-Stage Air Compressor – Which One Would You Choose?
After reading the entire comparison of single-stage vs. two-stage air compressors, you must have understood that the decision depends on your requirements and needs. If you are working on a small project, then a single-stage air compressor is the best option for you. On the other hand, the two-stage air compressor works for heavy-duty machines and bigger projects. Smaller pneumatic devices can easily run on both single-stage and two-stage air compressors, but bigger pneumatic devices need high air pressure and their performance disturbs due when you opt for the low-pressure or single-stage air compressor.
Which type is more expensive? The two-stage air compressor is expensive as more parts are used in it while the output of this air compressor is also more than the single-stage air compressor. They also require more maintenance as compared to the single-stage air compressor. You don’t have to spend a major part of your investment on single-stage air compressors as they are compact and small in the size. Carrying and moving these air compressors are also very easy tasks.
So, what’s your choice? We have tried our best to provide a comprehensive comparison of single-stage vs. two-stage air compressors.
Before you say goodbye, make sure to check out the following few hand-picked air compressors for your work.
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