A piston compressor is a positive-displacement machine that compresses gas using one or more pistons in a cylinder. They can be classified as one-stage, multi-stage, low-speed, or high-speed. They are widely used in various industries, including chemical, gas processing, cement, and refrigeration.
Compressors are mechanical devices that boost the pressure of a gas by significantly reducing its volume. Many small, medium-sized, and big businesses use compressors daily. Knowing more about compressors is crucial to opening or enhancing your business processes.
This article covers piston compressors, the most common and oldest industrial compressors. You will know more about piston compressors, their work, the common types available, and their uses.
What is a Piston Compressor?
A piston compressor – or reciprocating compressor – is a machine that relies heavily on the reciprocating action of one or more pistons to efficiently compress gas within a cylinder or cylinders and then discharge the compressed gas by valving into high-pressure-receiving tanks.
Piston compressors come in several models, though the most popular ones come in petrol, diesel, and electric-powered models.
How a Piston Compressor Works
Piston compressors use two stainless steel valve discs and a valve system. The piston travels downward to draw air into the cylinder. The largest of the two discs flexes to fold downward, allowing air to pass.
As the piston travels upward, the large disc flexes again to seal against the valve seat. The compressed air is forced through a hole in the valve seat and swiftly delivered to the end process.
Generally, a piston or reciprocating compressor is positive-displacement equipment utilizing a cylinder and piston-powered crankshaft. The compressed air has increased density but decreased volume without turning it into liquid.
Piston compressors often require cooling by air or water. They are available in oil-free and oil types and are developed to perform capacity and pressure selection optimally. The pressure within the cylinder determines when the valves are closed or opened.
Types of Piston Compressors
Piston compressors are classified into more than a few types. One of the common types is the automotive or trunk piston type. This compressor’s piston is connected to a connecting rod, which is also directly connected to the crankshaft. Compressors in this category are of the single-acting cylinder type, often limited to smaller air compressors and refrigeration services.
Piston compressors can also be single-stage or multi-stage, so you can choose based on the specific compressor type you want for your business in order to keep it moving.
Here are the sub-types of piston compressors:
One-Stage Piston Compressors
A one-stage piston compressor is equipped with one or more cylinders. Each of these cylinders compresses air from atmospheric pressure to operational pressure.
Multi-Stage Piston Compressors
The multi-stage piston compressor has at least two cylinders connected serially. Air is gradually compressed until it reaches the required pressure level.
Between these air compression steps, the air is cooled with ambient air. This significantly boosts efficiency while accomplishing a much higher pressure level than one-stage piston compressors.
Low-Speed Piston Compressors
This type of piston compressor is called an integral machine since the driver is mounted onto the equipment’s frame. It is usually heavier and larger than the high-speed piston compressor and often requires add-ons such as pulse and noise suppressors.
Low-speed piston compressors require lower maintenance and often operate at speeds ranging from 200 to 600 revolutions per minute, hence the name.
High-Speed Piston Compressors (Separable)
On the other hand, high-speed piston compressors are ‘separable’ since they are usually separate from their energy source. Motors or engines power this type. They are available in various sizes, easy to transport or move, and are relatively cheap.
However, high-speed piston compressors require more maintenance than their low-speed counterparts. More maintenance equals higher maintenance costs required compared to integral piston compressors.
High-speed piston compressors earned that name because they can only function efficiently with speeds ranging from 900 to 1,800 revolutions per minute.
Uses of the Piston Compressor (Integral)
Piston compressors are highly suitable for a wide range of compressed air needs. A one-stage piston compressor generates up to 8 bar, while multi-stage piston compressors can produce up to 15 bar or more.
Therefore, this makes piston compressors incredibly popular in the following industries:
- Chemical industries
- Gas processing industries
- Cement industries
- Refrigeration technology
- Refineries and oil plants, etc.
Nevertheless, every work environment has a piston compressor for which it is suitable. This is why it is important to consider the environment in which your piston compressor will function before making a final buying decision.
You will also need to consider these four additional points when selecting the perfect piston compressor that will keep your business moving:
- The most appropriate size of piston compressors
- The technology powering piston compressors, e.g., do you prefer oil-injected or oil-free piston compressors? Etc.
- The specific piston compressor you need for your own business
- Your budget
Piston Compressor Maintenance
To prolong or increase the lifespan of your piston compressor, proper maintenance must be carried out from time to time. During maintenance, all electricity from the main switch must be shut off while all compressed air summarily discharged.
Maintenance can be carried out weekly or monthly. But this depends on the intensity of day-to-day operations. Daily checks should also be carried out, including checking the oil level and other machine parts before it is switched on.
If the oil level is low, add more until it reaches the appropriate level. Oil addition frequency, as well as the amount of oil added per time, should be noted. The piston compressor may require in-depth servicing if these metrics are in excess.
The piston compressor is one of the most popular and versatile machines used across various industries today. They are available in various types and designs and help keep small, medium-sized, and big businesses moving forward based on their daily processes. If you’re looking for custom cylinders, rods, and pistons for your piston compressor, contact Samco today.