Hydraulic valves as used in industrial applications are built in several pressure ranges. The majority of present applications are in the range of 0 to 1500 lb per sq in., but the trend is toward higher pressures. Various types of valves are used in hydraulic systems to control or regulate the flow medium. Basically valves are expected to control:
- Blocking or stopping of flow
- Direction of flow
- Pressure of flow media
- Flow quantity
- In a hydraulic machine the actuators make to and fro motion.
Hence the direction of oil feeding the cylinder or motor needs to be
reversed. This means that the direction of oil flow is an essential
aspect of hydraulic operation. This is achieved by direction control
- Oil energy does the work due to pressure in the oil system. In a
mechanical or hydraulic system there may be a need to increase or
decrease the oil pressure depending on the specific requirement.
Hence a group of valves called pressure control valves have been
- The speed of the actuators needs to be altered as per operational requirement. For this purpose hydraulic systems use flow control valves.