Through years of on-site experience, the company has concluded that the causes of air compressor oil separator pressure faults mainly fall into the following four categories:

1.Oil pollution leads to large oil separator  pressure difference

2.The oil separator pressure difference sensor system falsely reports the oil separator pressure difference

3.The failure of the minimum pressure valve causes the oil separator pressure difference to be large

4.The panel shows that the oil pressure difference is unstable, and the safety valve of the oil barrel jumps when it is serious.

1. Oil pollution leads to large oil separator pressure difference

Problem performance: The oil pressure difference rises rapidly in a short period of time during machine maintenance, and exceeds 1 bar (kg) in severe cases. If the oil pressure difference exceeds 1 bar, the controller panel will display a large oil pressure difference alarm.

Analysis of the reasons: When the oil separates the oil and the compressed air, the oil pollutants also stay on its filter material, which increases the resistance and the pressure difference. Main sources of pollutants: 1. Air intake system (the air and dust environment at the user site is poor, and the air intake system is not tightly sealed and has gaps); 2. Oil system (irrational oil selection, incomplete maintenance and oil change); 3. If the operating temperature of the machine is too high, it will cause coking and carbon deposition or long-term low-temperature operation, and there is a lot of water in the oil separator.

Handling suggestion: use a clean mineral water bottle to connect an appropriate amount of lubricating oil to the oil discharge port after the machine is shut down to relieve pressure. After precipitation, observe whether the lubricating oil is abnormal. For example, there are more particulate impurities at the bottom of the lubricating oil, oil viscous matter (high viscosity of oil), black lumpy carbon deposits, moisture, and odor. There are many small particles of impurities in the lubricating oil. It should be checked whether the air filter to the air inlet valve is in good condition.

It is recommended to replace the air filter frequently or use the nano heavy-duty air filter; the lubricating oil contains more oil viscous substances (high viscosity of oil), carbon deposits, and odors are mostly caused by oil deterioration. It is recommended to clean the oil circuit system and completely drain it. Replace the appropriate oil; it is best to control the temperature at 80-90 degrees after starting the operation. If the temperature is too high, it is recommended to find the fault point in time for cooling treatment; if there is more water in the lubricating oil or emulsification, it is recommended to appropriately increase the operating temperature of the machine. It is generally kept at 80-90 degrees, and if necessary, part of the condensed water is discharged from the oil discharge port of the oil separation barrel after the machine is shut down for 1-2 hours.

2. False report of  oil separator  pressure sensor system

Problem performance: The panel shows that the oil separator pressure difference is negative or the initial pressure difference exceeds 0.2bar, and the pressure difference rises rapidly when the oil is kept well.

Reason analysis: The initial pressure difference of oil is generally 0.1-0.2bar. When the oil is clean and pollution-free, the oil separator pressure difference is often different, and most of the pressure difference detection systems are false reports.

Handling suggestion: replace the  oil separator  pressure detection system. The false report of oil separator pressure difference is a hidden deep air compressor maintenance failure. A small number of after-sales technicians are easily misled by the panel alarm oil separator pressure difference when dealing with such faults. There are also some domestic air compressors whose oil separator pressure difference is displayed by the reading of the pressure gauge. After a long time of use, this kind of pressure gauge is likely to cause the data to be too large and false. It is best to check this kind of pressure gauge once every six months or replace it regularly.

3. The failure of the minimum pressure valve causes the oil separator pressure difference to be large

Problem performance: The panel of the air compressor shows that the oil separator pressure difference is large, and the gauge pressure of the pneumatic pressure reducing valve of the minimum pressure valve above the low pressure machine is relatively high, which is obviously higher than the normal value. For example, the normal opening pressure of the minimum pressure valve of a 3bar low-pressure machine is about 1bar. When the minimum pressure valve is used subsequently, the opening pressure becomes 2bar, and the opening pressure of the machine's minimum pressure valve increases significantly. This situation will cause a large pressure difference and mislead the belief that oil The pressure difference is large.

Analysis of the reasons: When compressed air acts on the minimum pressure valve, there will be a pressure drop when the minimum pressure valve is opened. The recommended standard for the pressure difference of the minimum pressure valve is generally controlled within 0.1bar. If the pressure drop of the minimum pressure valve exceeds 0.1bar, it is generally Minimum pressure valve failure.

Handling suggestion: The pressure drop of the minimum pressure valve exceeds the normal value. It is better to adjust the opening pressure of the minimum pressure valve or replace the minimum pressure valve maintenance kit. The general maintenance period is 8000 hours or 2 years. How to know the exact pressure drop difference caused by the minimum pressure valve of the air compressor? A more accurate old method is provided here, that is, after the machine has a large oil pressure difference, install two pressure gauges on the machine to measure the actual pressure before and after the oil separation, so that you can determine where the fault occurs and accurately find the cause and solve the problem.

4. The panel shows that the oil pressure difference is unstable, and the safety valve of the oil barrel jumps when it is serious.

Problem performance: 1. The T-pipe connection causes the panel to display a large fluctuation of the oil pressure difference; 2. The variable frequency operation panel of the variable frequency air compressor shows that the oil pressure difference fluctuates greatly; 3. The panel alarms the oil pressure difference fault and shows that the oil pressure difference is ** **bar, the oil separator safety valve jumps intermittently.

Reason analysis: 1. The connection of the T-shaped pipe will cause a large amount of condensed water to enter the air outlet pipe, resulting in abnormal airflow at the air outlet of the machine, which will cause fluctuations in the pressure before and after the oil separation, causing the panel oil pressure difference to be unstable; 2. Frequency conversion air compressor The normal operation is that the oil pressure difference fluctuates less, and the larger fluctuation is mostly the false pressure difference reported by the pressure difference sensor system. 0.10bar differential pressure fluctuation is normal; 3. Most of this phenomenon is due to the failure of the safety valve, the unloading of the machine, the insensitive movement of the minimum pressure valve, and the accidental blockage of the outlet pipe of the machine.

Handling suggestions: 1. In order to avoid unstable fluctuation of oil pressure difference, the exhaust pipe of the air compressor should be connected to the main pipe from above. If there are multiple air compressors, this connection method is even more necessary; 2. It is recommended to use a pressure gauge to detect The actual pressure before and after oil separation is compared with the pressure detected by the differential pressure sensor; 3. Carefully check the safety valve of the oil separation barrel, the loading and unloading of the intake valve, the minimum pressure valve, and whether there is any rupture inside the air outlet steam trap to determine one by one.