Cleaning And Maintenance of Hydraulic Presses

The Essentials of Cleaning

Hydraulic presses may be contaminated during production, commissioning, use and storage, so cleaning hydraulic presses is an important means to eliminate contamination and keep hydraulic oil, hydraulic components and pipelines clean. 

In production, the cleaning of hydraulic press usually includes main engine cleaning and whole machine cleaning. The specific cleaning content includes the entire hydraulic circuit of the hydraulic press. Before cleaning, the hydraulic press should be returned to actual operation to ensure cleaning is in place and operator safety. Hydraulic oil can be selected as the cleaning medium. The usual cleaning time is 2-4 hours, and in special cases it will not exceed 10 hours. The cleaning effect is based on the absence of impurities on the loop filter.

1.When cleaning the general hydraulic press, please use hydraulic oil or test oil for work, pay attention to the use of kerosene, gasoline, alcohol, steam and other liquids, because such liquids have a certain corrosiveness, will lead to hydraulic components, Damage to parts such as pipes, fuel tanks and seals. 

2.In the cleaning process of the hydraulic press, the operation of the hydraulic pump and the heating of the cleaning medium are carried out simultaneously. The temperature of the cleaning oil is generally controlled at 50-80 degrees Celsius, which makes it easier to remove rubber residues in the system. 

3.In the cleaning process of the hydraulic press, the tubing can be struck with a non-metallic rod, either continuously or discontinuously, which is conducive to removing impurities attached to the pipeline. 

4.The intermittent operation of the hydraulic pump is conducive to improving the cleaning effect, and the interval time is generally 20-30 seconds. 

5.Filters or strainers should be installed on the return line of the hydraulic oil line. At the beginning of cleaning, due to the large number of impurities, you can use a filter of 80 mesh. After cleaning for a while, it can be changed to a filter of 150 mesh or more. 

6.The cleaning time of the hydraulic press is usually 48-60 hours, and the specific time depends on factors such as the complexity of the hydraulic press, the filtration accuracy requirements and the degree of contamination. 

7.To prevent rust and turbidity caused by external moisture, the hydraulic press will continue to reload at the end of cleaning until the temperature returns to normal. 

After cleaning the hydraulic press, remember to drain the cleaning oil in the circuit. 

System Maintenance 

A system is generally flushed before it is officially put into use. The purpose of flushing is to remove contaminants, metal chips, fibrous compounds, iron cores, etc. remaining in the system. During the first two hours of work, even if the system is not completely damaged, it will will cause a series of failures. Therefore, the following steps should be followed to clean the oil circuit of the system:

1.  Wash the tank with an easy-to-dry cleaning solvent and remove the solvent residue with filtered air. 

2.Cleaning all lines of the system, in some cases it is necessary to impregnate the pipes and fittings.

3.An oil filter is installed in the line to protect the valve's oil supply and pressure lines.

4.A flushing plate is installed on the collector to replace precision valves, such as electro-hydraulic servo valves.

Check that all piping sizes are appropriate and that the connections are correct. 

If an electro-hydraulic servo valve is used in the system, the flushing plate of the servo valve should allow the oil to flow from the oil supply line to the collector and return directly to the oil tank, so that the oil can circulate repeatedly to flush the system and let the oil flow. Filter out the solid particles. During the flushing process, check the oil filter every 1-2 hours to prevent the oil filter from being blocked by pollutants. Do not open the bypass at this time. If the oil filter starts to be blocked, change the oil filter immediately.

The cycle of flushing is determined by the structure of the system and the degree of contamination of the system. If the sample of the filter medium has no or little foreign contamination, install a new oil filter, remove the flushing plate, and install the valve to work!