As a key component of the steam turbine control system, the electro-hydraulic servo valve has extremely strict requirements on the cleanliness of the oil. Today we will discuss the cleanliness requirements of the SM4-20(15)57-80/40-H607H electro-hydraulic servo valve for fire-resistant oil and how its filtration system should be configured to ensure the long-term reliable operation of the servo valve.

The electro-hydraulic servo valve SM4-20(15)57-80/40-H607H is a precision electro-hydraulic conversion device used to convert electrical signals into hydraulic signals to achieve precise adjustment of the steam turbine control system. Fire-resistant oil, due to its non-flammable, good stability and excellent lubrication properties, has become an ideal working medium for the servo valve.

The cleanliness of fire-resistant oil directly affects the performance and life of the servo valve. Tiny particles, moisture or chemical contaminants can cause blockage of the internal gap of the servo valve, accelerate wear, and reduce response speed and control accuracy. Therefore, the SM4-20(15)57-80/40-H607H servo valve has very high cleanliness requirements for fire-resistant fuel, usually following the ISO 4406 standard, and the recommended cleanliness level is NAS 1638 level 6 or better.

In order to meet the stringent cleanliness requirements of the servo valve, a reasonable filtration system configuration is essential. Filter elements must be installed at the inlet or outlet of the oil pump and oil tank in the hydraulic system to intercept particles and impurities and prevent them from entering the system. In the system return oil pipeline, a return oil filter must be installed to further remove pollutants in the system and ensure that the oil returned to the tank is clean. In addition, the moisture in the fire-resistant fuel will accelerate the aging of the oil and corrode metal parts, so a special oil regeneration device should be configured to remove moisture from the oil to keep the oil dry.

In summary, the steam turbine electro-hydraulic servo valve SM4-20(15)57-80/40-H607H has extremely strict requirements on the cleanliness of the fuel oil. It is necessary to reasonably configure the filtration system and implement an effective maintenance management strategy to ensure the long-term stable operation of the servo valve and thus ensure the safe and efficient operation of the steam turbine.