Oil pollution damages the lubrication performance of the oil film. If lubrication management is improper and pollution control is not strict, it will not only cause the working oil temperature of the hydraulic system to rise, but also accelerate the deterioration rate of the oil.

A high-quality product's hydraulic oil may result in severe pollution, and a large amount of used hydraulic oil should be scrapped as "waste oil" in advance, "replaced once, scrapped one batch". Some need to be replaced after only a month, a few months, six months, or a year. The hydraulic system malfunctioned, and in the end, these good oils had to be replaced and scrapped.

The pollution of hydraulic oil can be divided into three types:

Potential pollution

During the processing, assembly, testing, storage, and transportation of self-made parts, harmful substances such as casting sand, chips, abrasives, welding slag, rust, fine coating particles, rubber fragments, and dust are already latent in the hydraulic system before it starts working. Similarly, these pollutants can also be present in purchased parts.

Invasion of Pollution

During the operation of the hydraulic system, foreign pollutants (such as dust, moisture, and different types of oil) can enter the system through the oil tank vent and filling port. For example, pollutants can enter the system through the reciprocating piston rod, oil injected into the system, air flowing in the oil tank, splashed or condensed water droplets, and oil leakage flowing back into the oil tank, causing pollution.

It is generally believed that newly purchased hydraulic oil is clean. In fact, materials and coatings of containers, rubber of oil hoses, and dust in the atmosphere can all enter the oil. After experimental testing, the newly purchased hydraulic oil was filtered through a 100 mesh copper wire mesh and sampled for measurement. There were 30000 to 50000 particles of 5um or more per 100ml of oil. This type of oil can only be used for general hydraulic systems and cannot be used for hydraulic servo control systems.

If manual refueling is used, it will increase system pollution by 4-7 times. At the same time, during assembly and repair, it is easy for dust, lint, and other debris to enter the hydraulic system.

Regenerative pollution

Regenerative pollution refers to the pollutants that exist in hydraulic oil during the operation of hydraulic systems. Such as residual rust on parts, peeling paint chips, wear particles on moving parts and sealing materials, particles or fibers detached from filter materials, etc.

The products of physical, chemical, and biological changes in hydraulic oil can cause metal corrosion and particle rust, which can lead to regenerative pollution. Under high temperature and pressure, hydraulic oil generates pollutants such as oxides and resin oil deposits due to the action of media such as moisture, air, copper, and iron.

Pollution affects environmental benefits.

Now, on the one hand, hydraulic equipment is working with problems for a long time, which affects the reliability of equipment operation and shortens the life of hydraulic equipment, hydraulic components, and hydraulic oil by several times to tens of times, causing serious waste and loss of resources, greatly shortening the working life of oil products, and bringing worries to enterprises; On the other hand, if the equipment needs to be replaced with oil, it will be scrapped once.

In this way, it not only causes waste and loss of oil resources, but also increases environmental pollution, bringing a lot of trouble to the company in dealing with oil pollution.