What is the general oil content of compressed air in the air compressor room?

Many people are concerned about how much oil the compressed air from the air compressor room contains. This value actually depends on the type of air compressor and the standards implemented. Different equipment, different industries, the gap can be very large.

Ordinary oil injection screw machine: 3~5 mg/m & sup3;

this is the most common model in the industrial field. According to national standards, the liquid oil content in compressed air shall not exceed 5 mg/m & sup3;, and the oil vapor content shall not exceed 0.5 mg/m & sup3;. In actual operation, under normal conditions, the exhaust oil content of the oil injection screw machine is generally controlled at about 3ppm, that is, about 3 mg of oil per cubic meter of air. If it exceeds this value, the industry is usually called "running oil" or "flying oil", indicating that there may be a problem with the oil and gas separation system.

Oil-free air compressor: less than 0.01 mg/m & sup3;

according to ISO 8573-1, the highest cleanliness level of oil-free compressed air is Class 0, and the residual oil content is required to be less than 0.01 mg/m & sup3;. The oil-free machine mentioned here includes an oil-free water-lubricated air compressor. This kind of equipment uses water instead of lubricating oil to complete sealing and cooling. The output gas itself does not contain oil, which can meet the scenes with strict requirements on gas source cleanliness such as food, medicine and electronics.

The requirements of different industries vary significantly

• instrument gas (GB/T 4830-2015): oil content not exceeding 10 mg/m & sup3;
• electronic industry: general requirement is less than 0.1 mg/m & sup3;
• food, pharmaceutical industry: must be controlled at 0.01 mg/m & sup3; below
• general gas for chemical industry: no more than 5 mg/m & sup3;

A simple on-site judgment method

if you don't have a professional testing instrument at hand, you can take a dry paper towel and blow it against the air compressor exhaust port for three to five minutes. The paper towel does not change color obviously, indicating that the oil content is basically normal. If the paper towel is yellow or even oil drops appear, the oil content has exceeded the standard, and the oil and gas separator and oil return system need to be checked.

Generally speaking, the oil content of compressed air in ordinary air compressor room is usually 3~5 mg/m & sup3; In this range, the production line that requires the quality of the air source will press this value to 0.01 mg/m & sup3 through the oil-free water lubrication air compressor or the precision degreasing equipment at the back end. Even lower. When selecting the type, the actual demand of the gas end should be clearly defined, and then the equipment should be matched, so that the oil content will not be wasted.