Hydraulic fluids cleanliness

Cleanliness in hydraulic systems has received considerable attention recently. Some hydraulic systems, such as aerospace hydraulic systems, are extremely sensitive to contamination. Fluid cleanliness is of primary importance because contaminants can cause component malfunction, prevent proper valve seating, cause wear in components, and may increase the response time of servo valves. Fluid contaminants are discussed later in this chapter. 

The inside of a hydraulic system can only be kept as clean as the fluid added to it. Initial fluid cleanliness can be achieved by observing stringent cleanliness requirements (discussed later in this chapter) or by filtering all fluid added to the system. 

These misconceptions relate to the definitions applied to clean oil and dirty oil. It is this definition that influences the setting of appropriate target cleanliness levels for lubricating oils and hydraulic fluids. While there are numerous methods used to arrive at target cleanliness... 

Fine particulate contamination is the number one cause of failure for close tolerance hydraulic and lubrication systems. Electronic particle counting is the preferred method to determine and monitor fluid cleanliness. 

This type of technology has given rise to some considerable amount of debate within the pharmaceutical industry and the regulatory bodies. Concerns about the cleanliness of the machineiy and contamination of the polymer granules have been largely resolved so also have issues surrounding the quality of the services (cooling water, hydraulic fluids, etc.). The main area of contention... 

Cleanliness of the hydraulic fluid is critical to the satisfactory operation of the hydraulic press. Therefore, it is recommended that the pumping unit include a filtration system. Usually, there will be one or more filters of 3-10 pm, a magnetic trap, and perhaps suction strainers. 

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