If you're interested in learning more, I recommend searching for Peter Rohner's publications or books on industrial hydraulic control systems.
Most failures are contamination-related. Rohner provides ISO cleanliness codes, filter beta ratios, and a practical schedule for oil sampling. He famously writes, "A hydraulic system is a pump, a valve, a cylinder, and a filter. The rest are accessories." industrial hydraulic control peter rohner pdf
: Coverage of pressure, flow, and direction control valves, as well as cartridge valves and logic elements. If you're interested in learning more, I recommend
The curriculum of the book is logically structured to move from basic physics to complex automated control. If you're interested in learning more