The filter elements used in steam turbines all have strict requirement to ensure the safety operation of steam turbine, such as the turbine actuator filter elements, which is a key factor of the normal operation and maintenance of the actuator. Let’s take a close look at the steam turbine actuator filter element with Yoyik.

The hydraulic actuator of a steam turbine converts the secondary oil signal input by an amplifier or electro-hydraulic converter into a stroke output with sufficient power output to operate the regulating valve and control the steam inlet of the turbine.

The actuator is the last link in the regulating system of the steam turbine unit, which directly controls the steam intake of the steam turbine. Its quality has a significant impact on the static and dynamic characteristics of the regulating system, so the hydraulic servomotor is an extremely important component in the steam turbine regulating system, directly affecting the start-up, speed increase, grid connection, and load bearing of the unit.

The safety issues of steam turbine oil engines cannot be ignored. The actuator controls the speed control valve by relying on the pressure difference of high-pressure EH oil. The power oil entering the actuator is supplied by the EH oil main oil pump. Due to the generation of various small particles and impurities in the oil circuit operation, high-pressure oil also needs to be purified through a filter before entering the actuator to avoid contamination and damage to the actuator. Therefore, each actuator of the steam turbine needs to be equipped with a separate oil filter, including actuators for high pressure main valve, high pressure regulating valve, control valve and so on.

There are several regularly used filter elements for steam turbine actuator: DP301EA10V/-W inlet filter, QTL-6021A filter, DP201EA01V/-F flushing filter, etc.

The accuracy of the actuator filter element is a very important parameter, as it determines how small particles the filter element can filter out. Generally speaking, the accuracy of steam turbine filter elements is expressed in microns. For example, a 1 μm filter element can filter out particles of 1 μm size. The accuracy of the turbine filter element generally needs to be selected based on the specific usage environment and requirements. Excessive accuracy may lead to excessive resistance and shortened service life, while low accuracy may not meet the filtration requirements and affect the normal operation of the equipment.

The filter element of the actuator needs to be replaced frequently. When replacing, first tighten the oil inlet shut-off valve on the actuator and gradually close the valve. When the valve is fully closed, the filter cover on the outside of the filter element can be unscrewed and the filter element can be pulled out. The filter element and core sleeve are equipped with smooth holes, but without threads. When replacing the filter element, it should be noted that when assembling and disassembling the filter element, do not rotate counterclockwise, otherwise the core sleeve may loosen and be pulled out, the filter element cannot be installed in place, and the filter cover cannot be properly covered, which may cause oil leakage.