Hazards of hydraulic system impurities

Hazards refer to the failure caused by hydraulic equipment. Faults can be divided into two sides: one is predictable, mainly because the particle wear reduces the performance of the hydraulic part, such as the decrease of the flow of the pump, the decrease of the speed of the hydraulic motor, the pressure relief of the valve, the failure of the oil cylinder to maintain its position, etc. The other is a sudden accident, such as blockage of oil circuit, jamming of the valve core, etc. pollution hazard can be learned through tests such as pollution sensitivity, lifespan, wear amount and so on.

According to the statistics of actual maintenance work, the types of contaminated particles in the hydraulic system are:

abrasive grain

Polytetrafluoroethylene fragments

Cast molding sand

Machined coating chips

Argon arc welding and brazing slag

Burr detritus from the machined surface

Corrosion product

Muddy wear particles

Oil oxidation product

rag fiber 

However, in addition to the solid particles, contaminants are water, air, and chloride，etc. and their harm is different from that of the solid particles, while the hazard is still cannot be ignored. The presence of water and air provides an oxygen source for the high-pressure area inside the hydraulic element, which can lead to the oxidation of the element surface and the oil itself, and the mixing of water will invalidate the performance of the system alarm. The mixing of chlorine causes corrosion of the components. After the air is mixed, it exists in oil in the form of free, mixed and dissolved. Free air will reduce the elastic die of oil volume. Mixed air suspended in oil as a bubble will cause cavitation destruction and increase noise.