This port will allow oil poured into the compressor to flow down and into the oil pan located below the piston head assembly. You want to comply with the compressor manufacturer's warranty guidelines. Unspecified oil replacements, such as engine oil, could void the warranty and eliminate any additional benefits. Manufacturer can rely on compressor oil to be formulated specifically for air compressors.
The same cannot be said for other types of oil, even though they are technically a viable substitute. Whether standard, synthetic or substitute, the oil you use should not be detergent. If your warranty guidelines do not specify an oil type, we recommend that you use a standard compressor oil weighing 20 or 30. A 30 weight oil is more viscous and will provide better protection in the warmer months.
While 30 weight oil is more effective at coating parts, it may become too thick to use if the temperature drops too low. A 20 weight oil will perform much better in cold environments to ensure the compressor starts and runs when needed. However, not all compressors are the same, but all oil-lubricated units will have some type of oil fill port. Air compressor oil is a standard or synthetic oil manufactured specifically for air compressors.
Unlike engine oil, air compressor oil is detergent-free and generally has lower amounts of carbon, sulfur, and other contaminants that can cause buildup. Oil-free compressors also typically use a universal motor, which won't last as long as an induction motor. Instead, it would be best to stock a compressor oil that is made specifically for your air compressor. Having an oil lubricated air compressor has several advantages: they are powerful, relatively quiet, and can last for decades if taken good care of.
When you're ready to choose an air compressor, it's important that you understand the three main types of compressors. The average compressor element will operate at around 2.5 bar, and air compression can only cause the unit to operate at a temperature of up to 180 degrees. Oil-free air compressors are a smarter option and require careful consideration for your operations. However, in most cases, it is possible to remove enough oil from the air supply through in-line filtration to meet even the most demanding specifications.
Understanding the general pressurization of air compressors is quite simple, as it often works the same way in oil-injected and oil-free units. Rotary screw air compressors are sometimes referred to as “oil flooding” or “oil injection”, which describes how oil is injected into the rotor housing. Oil is pumped from an oil sump into the gearbox and cooled through an oil cooler and oil filter before being used to cool the compressor or gearbox parts. Typically, an oil-free compressor will not last as long as an oil-lubricated model because its pre-lubrication will gradually wear out and degrade over time.
If the air compressor does not have a sight glass, remove the oil filler cap and look inside for a dipstick. If you have added the wrong oil to your air compressor, it is best to remove it from the system and replace it with the right lubricant as soon as possible. Mixing oils is never good, but mixing any of these substitutes would be even worse for your compressor. Leave the compressor in the sun for a while before starting work, or let it run and fill the air tank before starting.
In fact, many of the small DIY type air compressors now available in large stores are oil-free with added lubrication. .
