Compressors are essential in multiple industries; from manufacturing to construction and energy, used in applications such as pneumatic tools and motors, oil exploration and production, and inflating tyres.
These types of machines compress air or gases for various applications. To keep compressors functioning well, it is essential to use the right type of lubricant.
Air compressor oil and gas compressor oil differ in their formulation and purpose, with air compressor oil specifically for compressing air, and gas compressor oil being designed for various gases like natural gas or propane – but this is very much a ‘top line’ explanation.
In this article, we will expand on the main differences between, and similarities of, gas compressor and air compressor oil, breaking down their individual roles, formulations, types and considerations.
Air compressor oil
Purpose
The primary purpose of air compressor oil is to lubricate and cool the internal components of air compressors. This prevents them from experiencing wear and tear during operation.
Air compressors operate under continuous load and at varying temperatures. For this reason, oil plays an important role in reducing friction and the risk of damage, which is conducive to the smooth operation of air compressors.
Formulation
Air compressor oils are formulated with additives that protect the internal parts of the compressor from a range of potential issues.
These additives include substances that prevent oxidation (which can cause rust), reduce foaming (which can interfere with lubrication) and protect against corrosion.
Air compressor oils are designed to maintain optimal viscosity (resistance to flow) across a wide range of temperatures. This is the key to consistent performance even under extreme conditions, and is essential to extending the working life of the compressor.
Types
There are two main types of air compressor oil:
Standard (mineral) oil
This is a common, inexpensive form of air compressor oil, which is suitable for less demanding applications. Offering basic lubrication, mineral oils are usually used in smaller air compressors.
Synthetic oil
Synthetic air compressor oil offers superior lubrication and protection and is designed for more demanding environments. Typically used in industrial applications, it can withstand higher temperatures and loads and offers superior protection.
Usage
Air compressor oils are used in machines that compress air for various applications. Common uses include providing power for pneumatic tools, paint spraying, industrial processes and systems that rely on compressed air.
It is important to note that motor oil or hydraulic oil should not be used in air compressors, as these oils lack the necessary additives and properties required for proper compressor lubrication.
Gas compressor oil
Purpose
Gas compressor oil offers similar benefits to air compressor oil, but it is specifically formulated for gas compressors.
This type of compressor is used to compress gases such as natural gas, propane, nitrogen and other industrial gases. Like air compressor oil, gas compressor oil lubricates and cools the internal components of the compressor. Additionally, it must withstand the high pressures and temperatures generated during gas compression.
Formulation
Specifically designed to handle the unique demands of gas compression, gas compressor oils are designed to withstand high pressures and temperatures, as well as prevent reactions with the compressed gas. The oil must be formulated to resist reactions from specific gases.
Maintaining high viscosity under challenging operating conditions – as it is with air compressor oil – is often a design requirement.
Types
There are several types of gas compressor oils, each suited to different applications:
PAG (Polyalkylene Glycol) oils
PAG oils are non-volatile – not easily absorbing gases – and are used in applications where process gases are compressed. They help to reduce the risk of chemical reactions between the oil and the compressed gas.
Synthetic oils
Synthetic gas compressor oils are also widely used in more demanding gas compression applications. These oils offer superior performance and protection, especially in high-pressure or high-temperature environments. Synthetic oils are often required in large-scale gas compressors, such as those used in pipelines and gas storage.
Usage
Gas compressor oils are used in compressors that are designed to compress gases for a wide range of applications. These can include pipeline transportation, industrial gas processing and gas storage operations.
In industries such as natural gas production, petrochemicals and energy generation – where gas must be compressed for transportation or used in other processes – gas compressor oils have a critical role.
The type of gas being compressed can significantly influence the choice of compressor oil, as different gases have different properties and can interact with the lubricant in unique ways.
As we’ve discussed, there are several ‘crossovers’ between the purpose of air compressor oil and gas compressor oil, and the benefits which they provide. However, the two products are distinctly different when it comes to their formulations and the applications that they are used in.
