Syllabus of Hydraulic System

Hydraulic System

  • DCV with Auxillary Valves
  • Actuators and Selection of Actuators
  • Proportional valve and Theory of Servo Valves
  • Hydraulic Symbols and Design of Basic Circuits, Design of Basic Circuits
  • Automsim Software Working Procedure with Basic Circuit Workouts
  • Practical Workouts of Basic Hydraulic Setup, Proportional Valve Hydraulic Setup
  • Maintenance of Hydraulic System
  • Introduction to Electro Hydraulics and Automation
  • Operation & Types of Relays and Gate Functions Using Relays
  • Architecture of PLC & Explanation,
  • Types of PLC and Programming Languages & Explanations
  • Sensor Wiring , MCC Panel Wiring
  • PLC Control Panel Wiring
  • Do’s & Don’ts of Ladder Diagram and Gate functions
  • Latching & Unlatching with Memory Concepts
  • Working in PLC Software withBasic Programming
  • Online Interfacing of PLC, Timers and Counters
  • Programming of Simple Hydraulic Logics
  • Programming of Hydraulic Machine Process

In the industry we use three methods for transmitting power from one point to another. Mechanical transmission is through shafts, gears, chains, belts, etc. Electrical transmission is through wires, transformers, etc. Fluid power is through liquids or gas in a confined space. Fluid power is the technology that deals with the generation, control and transmission of forces and movement of mechanical element or system with the use of pressurized fluids in a confined system. Both liquids and gases are- considered fluids. Fluid power system includes a hydraulic system (hydra meaning water in Greek) and a pneumatic system (pneuma meaning air in Greek).

Oil hydraulic employs pressurized liquid petroleum oils and synthetic oils, and pneumatic employs compressed air that is released to the atmosphere after performing the work.Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example.In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and becomes pressurised according to the resistance present.The fluid is controlled directly or automatically by control valves and distributed through hoses, tubes, and/or pipes.

Hydraulic systems are power-transmitting assemblies employing pressurized liquid as a fluid for transmitting energy from an energy-generating source to an energy-using point to accomplish useful work.

The functions of various components are as follows:


  1. The hydraulic actuator is a device used to convert the fluid power into mechanical power to do useful work. The actuator may be of the linear type (e.g., hydraulic cylinder) or rotary type (e.g., hydraulic motor) to provide linear or rotary motion, respectively.
  2. The hydraulic pump is used to force the fluid from the reservoir to rest of the hydraulic circuit by converting mechanical energy into hydraulic energy.
  3. Valves are used to control the direction, pressure and flow rate of a fluid flowing through the circuit.
  4. External power supply (motor) is required to drive the pump.
  5. Reservoir is used to hold the hydraulic liquid, usually hydraulic oil.
  6. Piping system carries the hydraulic oil from one place to another.
  7. Filters are used to remove any foreign particles so as keep the fluid system clean and efficient, as well as avoid damage to the actuator and valves.
  8. Pressure regulator regulates (i.e., maintains) the required level of pressure in the hydraulic fluid.


The piping of closed-loop type with fluid transferred from the storage tank to one side of the piston and returned back from the other side of the piston to the tank. Fluid is drawn from the tank by a pump that produces fluid flow at the required level of pressure. If the fluid pressure exceeds the required level, then the excess fluid returns back to the reservoir and remains there until the pressure acquires the required level.


Advantages of Hydraulics

Liquid does not absorb any of the supplied energy.

Capable of moving much higher loads and providing much higher forces due to the incompressibility.

The hydraulic working fluid is basically incompressible, leading to a minimum of spring action.

When hydraulic fluid flow is stopped, the slightest motion of the load releases the pressure on the load; there is no need to “bleed off” pressurized air to release the pressure on the load.

Highly responsive compared to pneumatics.

Supply more power than pneumatics.

Can also do many purposes at one time: lubrication, cooling and power transmission.