What are the selection criteria and precautions for hydraulic oil in Hydraulic Multifunctional Drilling Rigs?

What are the selection criteria and precautions for hydraulic oil in Hydraulic Multifunctional Drilling Rigs?

Selection of Hydraulic Oil for the Hydraulic System of Hydraulic Multifunctional Drilling Rigs

Generally speaking, hydraulic oil should meet the following requirements:

It must not contain steam, air, or other impurities that are prone to vaporization and gas formation.

It should have good lubricating properties and high oil film strength.

It must exhibit high chemical stability.

It should have appropriate viscosity and good viscosity-temperature performance.

Lanchou or Shangchou hydraulic oil (20/40 nm²/s) is recommended for Hydraulic Multifunctional Drilling Rigs. If these are unavailable, #30 mechanical oil can be used in summer, and #20 mechanical oil in winter.

Hazards and Preventive Measures for Hydraulic Oil Contamination

Hydraulic system contamination is a major cause of hydraulic failures. Pollutants entering the system can accelerate wear, scoring, burning, or even damage of hydraulic components, cause valve malfunctions, or lead to noise. Pollutants can clog the throttle holes or gaps of hydraulic components, altering the system's performance, causing operational disorders, or even complete failure, resulting in accidents due to erroneous actions.

Dust particles in hydraulic cylinders can accelerate seal damage, scratch the inner surface of the cylinder, increase leakage, reduce thrust, cause unstable operation, crawling, speed reduction, and produce abnormal noises and vibrations. They may also clog filters, making it difficult for the hydraulic pump to suction oil and causing poor return oil flow, leading to cavitation, vibrations, and noise. Severe clogging can cause excessive resistance, rupture the filter, and completely lose its filtering function, resulting in a vicious cycle in the hydraulic system. Therefore, it is essential to strengthen management, prevent oil contamination, and ensure the safe and reliable operation of the hydraulic system.

(1) Hazards of Oil Contamination to the Hydraulic System:

Clogging hydraulic components, such as the clearance between moving parts of pumps and valves, and blocking small throttle holes, damping holes, and valve ports, preventing components from functioning properly.

Pollutants entering the clearance between moving parts can scratch mating surfaces, damage precision and surface roughness, accelerate wear, increase leakage, and sometimes cause valve jamming, leading to component failure.

Excessive pollutants in the oil can clog the oil pump suction filter, increasing suction resistance, preventing the pump from operating normally, and causing noise and vibrations.

Pollutants in the oil can deteriorate the oil quality. Water mixing into the oil can cause emulsification, reduce lubricating performance, increase acidity, shorten component service life, and increase leakage.

(2) Measures to Prevent Oil Contamination:

Among the common failures in the hydraulic system of Hydraulic Multifunctional Drilling Rigs, many are caused by unclean oil. Therefore, maintaining clean oil is a critical aspect of hydraulic equipment maintenance. Measures to prevent oil contamination include:

Keeping the area around the oil tank clean and sealing the tank with a cover.

Regularly replacing the oil in the tank, generally after every 1,000 cumulative working hours.

Using a filter with 120 mesh or finer when refilling oil.

Regularly inspecting and cleaning filters.

Periodically cleaning hydraulic components with kerosene and clearing pipelines.

Regularly inspecting pipe connections and seals between pipelines and components.