Types and sources of contaminants

Pollutants are substances that harm the system in the oil of the hydraulic system. They exist in different forms in the oil, and can be divided into solid pollutants, liquid pollutants and gaseous pollutants according to their physical forms.

Solid pollutants can be divided into hard pollutants, including diamond, cutting, silica sand, dust, wear metal and metal oxide. Soft contaminants include additives, water aggregates, oil breakdown and polymers, and cotton and fiber brought in during maintenance.

Liquid pollutant is usually cut groove oil, water, paint, chlorine that do not meet the requirements of the system. It is usually difficult to remove them. Therefore, when selecting hydraulic oil, the hydraulic oil that meets the system standards should be selected to avoid some unnecessary failures.

Gaseous pollutants are mainly air mixed into the system. These particles are often so small that they can't settle down and float in the oil and are eventually squeezed into the gaps between the various valves that are essential to a reliable hydraulic system for limited control, importance, and accuracy.

The sources of pollutants in system oil mainly include the following aspects.

1) External invading pollutants: the external invading pollutants mainly consist of sand and gravel or dust in the atmosphere, and usually invade the system through the oil tank pores, seal shaft of oil cylinder, pump and motor, etc. It's mostly the impact of the use environment.

2) Internal pollutants: the residual pollutants have residual pollutants in the parts during processing, assembly, debugging, packaging, storage, transportation and installation. Of course, these processes cannot be avoided, but they can be minimized. Some special components need to be carried out in the environment of clean room or clean platform during assembly and debugging.

3) Hydraulic system: the particles are produced in the operation process of the result of the components, the sand castings, pump, valve and joint off metal particles, the pipe corrosion exfoliation with its oil oxidation and decomposition of particles and colloidal material. More serious is that the piping system has some impurities before putting into operation without flushing.