The key difference between Pag oil and ester oil is that Pag oil comes in different viscosities, whereas ester oil comes in a single viscosity.
Both Pag oil and ester oil are synthetic lubricants. These two oils are compatible with each other. However, they have different viscosity values and viscosity grades.
CONTENTS
1. Overview and Key Difference
2. What is Pag Oil
3. What is Ester Oil
4. Pag Oil vs Ester Oil in Tabular Form
5. Summary – Pag Oil vs Ester Oil
What is Pag Oil (Polyalkylene Glycol Oil)?
Pag oil or polyalkylene glycol oil is a man-made lubricant that is useful in both R134a systems and the latest R1234yf systems. This oil is commonly used in compressors, gearboxes, air conditioning systems, metalworking, quenching, and hydraulic systems in which fire resistance or environmental acceptability is required. Sometimes, we can use Pao oil (Polyalphaolefin oil) instead of Pag oil. Pao oil is preferred because it does not absorb moisture from the air as other oils do.
Pag oil is moderately polar, and it gives them moderate film strength properties. There is a very high viscosity index (180 to 280) and also a good low and high-temperature ability. Pag oil is available in the market in different viscosities. For example, PAG 46, (the most popular viscosity oil), PAG 100, and PAG 150 are commonly used for R-134a systems. Moreover, this oil can burn off cleanly, leaving no residue. It has been used as a carrier oil for solid lubricants for high-temperature chain lubrication. There are some versions of food grade and biodegradable grades as well. Pag oil is useful as a compressor oil in rotary screw and reciprocating units, worm gear oils, fire-resistant lubricants, metalworking fluids, and brake fluids.
What is Ester Oil?
Ester oil is a synthetic base oil that is chemically synthesized. Usually, it is useful in passenger car air-conditioning compressors, refrigerators, and other industrial applications. Moreover, ester oil is one of the classes of synthetic oils that are used in Mobil 1TM oils as well.
Typically, ester oil has a higher degree of solvency compared to group II, III, or Pao base oils. In other words, this oil can dissolve additives and deposits more readily. Also, this can cause some seals to swell slightly and can remove some paint.
Ester oil is made from alcohol and carboxylic acids. Water is a byproduct of this esterification reaction. Since all the esterification reactions are reversible, water can break ester back into the acid and alcohol components.
What is the Difference Between Pag Oil and Ester Oil?
Pag oil and ester oil are two important types of lubricant oils. The key difference between Pag oil and ester oil is that Pag oil comes in different viscosities, whereas ester oil comes in a single viscosity. Therefore, there is a range of viscosity grades for Pag oil, while there is only one viscosity grade for ester oil. Moreover, Pag oil is recommended to be used as a refrigerant oil for most R134a vehicles, while ester oils are recommended and currently used only with the R12 or retrofitted AC systems.
The below infographic presents the differences between Pag oil and ester oil in tabular form for side-by-side comparison.
Summary – Pag Oil vs Ester Oil
Pag oil or polyalkylene glycol oil is a man-made lubricant that is useful in both R134a systems and the latest R1234yf systems, while ester oil is a synthetic base oil that is chemically synthesized. The key difference between Pag oil and ester oil is that Pag oil comes in different viscosities, whereas ester oil comes in a single viscosity.
Reference:
1. Beatty, Daryl. “Polyalkylene Glycol Synthetic Pag Oil Explained.” Machinery Lubrication, Noria Corporation, 12 Jan. 2019.
Image Courtesy:
1. “Close-up of red and blue hoses for A/C recharge. Refrigerant gas refill and compressor oil change” By Ivan Radic (CC BY 2.0) via Flickr
2. “FANFARO Podukte” By Albert Badojan – Die hat der Grafiker von SCT Lubricants indessen Auftrag erstellt! (CC BY-SA 4.0) via Commons Wikimedia