Before a system is put into operation, it generally needs to be flushed. The purpose of flushing is to remove contaminants, metal shavings, fibrous compounds, iron core, etc., remaining in the system. Even if the system isn't completely damaged during the first two hours of operation, this flushing can cause a series of malfunctions. Therefore, the following steps should be taken to clean the system's oil circuitry:
1. Clean the oil tank with an easy-drying cleaning solvent, then remove any solvent residue with filtered air.
2. Clean all system piping. In some cases, it may be necessary to immerse the piping and connectors.
3. Install oil filters in the piping to protect the valve's supply and pressure lines.
4. Install a flushing plate on the manifold to replace precision valves, such as electro-hydraulic servo valves.
5. Check that all piping dimensions are appropriate and connections are correct.
If the system uses an electro-hydraulic servo valve, I'd like to elaborate a bit more. The flushing plate of the servo valve should allow the oil to flow from the oil supply line to the manifold and directly back to the oil tank. This allows the oil to circulate repeatedly to flush the system and let the oil filter remove solid particles. During the flushing process, the oil filter should be checked every 1 to 2 hours to prevent it from being clogged by contaminants. Do not open the bypass during this time. If the oil filter is found to be clogged, replace it immediately.
