Why do compressors need fluids?

To really understand compressor fluids, one should first understand the main function a fluid performs in a rotary screw air compressor. In many ways, a compressor fluid is to an air compressor what blood is to the human body. In fact you might say fluid is the lifeblood of an air compressor. While your heart pumps and circulates blood to keep your body functioning, an air compressor is circulating fluid to keep the machine functioning properly. So according to this analogy, the compressor air end would be equivalent to the body’s heart.

To optimize their value, all air compressor fluids should effectively perform three primary functions:

1. Remove the Heat of Compression. The heat is not caused by friction, but by the physics of the air compression itself.
2. Seal the Rotors. Since the rotors do not touch, the fluid creates the airtight seal between rotors.
3. Lubricate the Bearings. This ensures smooth, trouble-free performance.

The two primary enemies of rotary screw air compressors are HEAT and VARNISH. Both are directly related because high temperatures tend to create more varnish, while more varnish will, in turn, create more heat. When combined, the two create a vicious circle.

Know the base stocks

In the current market there are hundreds of compressor fluids, dozens of fluid manufacturers, and hundreds of resellers striving to earn your business. While most of these fluids have different base stocks, each is unique and has different properties—some good, and some not so good. The remainder of this article will address the factors that make certain base stocks more environmentally compatible and bottom-line friendly than others.

The following base stocks are commonly used in compressor fluids today

Hydrocarbons

Hydrocarbon-based lubricants have been around nearly as long as the rotary screw air compressor itself. Originally all rotary screw compressors used hydrocarbon-based fluids; however, today’s greatly improved technology has literally left hydrocarbons in the rear view mirror.

Most hydrocarbons lubricate well, seal the rotors, and contain anti-corrosive additives. And, although these products are usually the lowest priced, they frequently are accompanied by hidden added costs. Hydrocarbons do not transfer as much heat as synthetics, and they also varnish easily in the compressor. As we mentioned earlier, varnish is the number one problem for rotary screw compressors. Unlike other base stocks, the condensate produced by compressors using hydrocarbons is not biodegradeable.

Bottom Line: Hydrocarbons have the potential to cause varnish, which leads to a less efficient air compressor, and could potentially cause up to 10% more energy consumption. The compressor condensate produced by hydrocarbon-based products is also not biodegradeable which leads to expensive condensate disposal costs. The fact is, hydrocarbons do not offer the combination of properties to effectively reduce your environmental footprint.

Polyalphaolefin (PAO)

Essentially the best fluids the petroleum companies have to offer, PAOs comprise the top-of-the-line hydrocarbon-based products. While most offer a higher purity level than the basic hydrocarbons, they still suffer from many of the same drawbacks as basic hydrocarbon fluids. For instance, PAOs are as limited in heat transfer as the rest of the hydrocarbon-based oils and will varnish if run at high enough temperatures. In addition, the compressor condensate produced by these products is also non-biodegradeable.

Bottom Line: PAOs do offer better performance than hydrocarbons, but they do not offer the right combination of features to reduce your environmental footprint. In addition, they have the potential to cause varnish and can ultimately lead your compressor down a path of major inefficiencies. Lastly, the compressor condensate produced by PAOs must be disposed of, which can directly affect both the company’s bottom line and the environment.

Why Do Hydrocarbon-Base Stocks Varnish?

• All components are liquid at ambient temperature
• Some become solid at higher temperature
• Some tend to plate on metal parts
• The varnish they create will insulate and reduce heat removal, thus causing temperatures to rise and solid components to form

Why do compressors need fluids?

To really understand compressor fluids, one should first understand the main function a fluid performs in a rotary screw air compressor. In many ways, a compressor fluid is to an air compressor what blood is to the human body. In fact you might say fluid is the lifeblood of an air compressor. While your heart pumps and circulates blood to keep your body functioning, an air compressor is circulating fluid to keep the machine functioning properly. So according to this analogy, the compressor air end would be equivalent to the body’s heart.

To optimize their value, all air compressor fluids should effectively perform three primary functions:

1. Remove the Heat of Compression. The heat is not caused by friction, but by the physics of the air compression itself.
2. Seal the Rotors. Since the rotors do not touch, the fluid creates the airtight seal between rotors.
3. Lubricate the Bearings. This ensures smooth, trouble-free performance.

The two primary enemies of rotary screw air compressors are HEAT and VARNISH. Both are directly related because high temperatures tend to create more varnish, while more varnish will, in turn, create more heat. When combined, the two create a vicious circle.

Know the base stocks

In the current market there are hundreds of compressor fluids, dozens of fluid manufacturers, and hundreds of resellers striving to earn your business. While most of these fluids have different base stocks, each is unique and has different properties—some good, and some not so good. The remainder of this article will address the factors that make certain base stocks more environmentally compatible and bottom-line friendly than others.

The following base stocks are commonly used in compressor fluids today

Hydrocarbons

Hydrocarbon-based lubricants have been around nearly as long as the rotary screw air compressor itself. Originally all rotary screw compressors used hydrocarbon-based fluids; however, today’s greatly improved technology has literally left hydrocarbons in the rear view mirror.

Most hydrocarbons lubricate well, seal the rotors, and contain anti-corrosive additives. And, although these products are usually the lowest priced, they frequently are accompanied by hidden added costs. Hydrocarbons do not transfer as much heat as synthetics, and they also varnish easily in the compressor. As we mentioned earlier, varnish is the number one problem for rotary screw compressors. Unlike other base stocks, the condensate produced by compressors using hydrocarbons is not biodegradeable.

Bottom Line: Hydrocarbons have the potential to cause varnish, which leads to a less efficient air compressor, and could potentially cause up to 10% more energy consumption. The compressor condensate produced by hydrocarbon-based products is also not biodegradeable which leads to expensive condensate disposal costs. The fact is, hydrocarbons do not offer the combination of properties to effectively reduce your environmental footprint.

Polyalphaolefin (PAO)

Essentially the best fluids the petroleum companies have to offer, PAOs comprise the top-of-the-line hydrocarbon-based products. While most offer a higher purity level than the basic hydrocarbons, they still suffer from many of the same drawbacks as basic hydrocarbon fluids. For instance, PAOs are as limited in heat transfer as the rest of the hydrocarbon-based oils and will varnish if run at high enough temperatures. In addition, the compressor condensate produced by these products is also non-biodegradeable.

Bottom Line: PAOs do offer better performance than hydrocarbons, but they do not offer the right combination of features to reduce your environmental footprint. In addition, they have the potential to cause varnish and can ultimately lead your compressor down a path of major inefficiencies. Lastly, the compressor condensate produced by PAOs must be disposed of, which can directly affect both the company’s bottom line and the environment.

Why Do Hydrocarbon-Base Stocks Varnish?

• All components are liquid at ambient temperature
• Some become solid at higher temperature
• Some tend to plate on metal parts
• The varnish they create will insulate and reduce heat removal, thus causing temperatures to rise and solid components to form

The Importance of Fluids in Compressors To really understand compressor fluids, one should first understand the main function of how a fluid performs in a rotarty screw air compressor.

Why do compressors need fluids?

To really understand compressor fluids, one should first understand the main function how a fluid performs in a rotary screw air compressor. In many ways, a compressor fluid is to an air compressor what blood is to the human body. In fact you might say fluid is the lifeblood of an air compressor. While your heart pumps and circulates blood to keep your body functioning, an air compressor is circulating fluid to keep the machine functioning properly. So according to this analogy, the compressor air end would be equivalent to the body’s heart.

To optimize their value, all air compressor fluids should effectively perform three primary functions:

1. Remove the Heat of Compression. The heat is not caused by friction, but by the physics of the air compression itself.
2. Seal the Rotors. Since the rotors do not touch, the fluid creates the airtight seal between rotors.
3. Lubricate the Bearings. This ensures smooth, trouble-free performance.

The two primary enemies of rotary screw air compressors are HEAT and VARNISH. Both are directly related because high temperatures tend to create more varnish, while more varnish will, in turn, create more heat. When combined, the two create a vicious circle.

Know the base stocks

In the current market there are hundreds of compressor fluids, dozens of fluid manufacturers, and hundreds of resellers striving to earn your business. While most of these fluids have different base stocks, each is unique and has different properties—some good, and some not so good. The remainder of this article will address the factors that make certain base stocks more environmentally compatible and bottom-line friendly than others.

The following base stocks are commonly used in compressor fluids today

Hydrocarbons

Hydrocarbon-based lubricants have been around nearly as long as the rotary screw air compressor itself. Originally all rotary screw compressors used hydrocarbon-based fluids; however, today’s greatly improved technology has literally left hydrocarbons in the rear view mirror.

Most hydrocarbons lubricate well, seal the rotors, and contain anti-corrosive additives. And, although these products are usually the lowest priced, they frequently are accompanied by hidden added costs. Hydrocarbons do not transfer as much heat as synthetics, and they also varnish easily in the compressor. As we mentioned earlier, varnish is the number one problem for rotary screw compressors. Unlike other base stocks, the condensate produced by compressors using hydrocarbons is not biodegradeable.

Bottom Line: Hydrocarbons have the potential to cause varnish, which leads to a less efficient air compressor, and could potentially cause up to 10% more energy consumption. The compressor condensate produced by hydrocarbon-based products is also not biodegradeable which leads to expensive condensate disposal costs. The fact is, hydrocarbons do not offer the combination of properties to effectively reduce your environmental footprint.

Polyalphaolefin (PAO)

Essentially the best fluids the petroleum companies have to offer, PAOs comprise the top-of-the-line hydrocarbon-based products. While most offer a higher purity level than the basic hydrocarbons, they still suffer from many of the same drawbacks as basic hydrocarbon fluids. For instance, PAOs are as limited in heat transfer as the rest of the hydrocarbon-based oils and will varnish if run at high enough temperatures. In addition, the compressor condensate produced by these products is also non-biodegradeable.

Bottom Line: PAOs do offer better performance than hydrocarbons, but they do not offer the right combination of features to reduce your environmental footprint. In addition, they have the potential to cause varnish and can ultimately lead your compressor down a path of major inefficiencies. Lastly, the compressor condensate produced by PAOs must be disposed of, which can directly affect both the company’s bottom line and the environment.

Why Do Hydrocarbon-Base Stocks Varnish?

• All components are liquid at ambient temperature
• Some become solid at higher temperature
• Some tend to plate on metal parts
• The varnish they create will insulate and reduce heat removal, thus causing temperatures to rise and solid components to form