Hydraulic Systems – Parts, Applications and Advantages

What are the Hydraulic Systems?

Hydraulic systems are very common in different kinds of applications. We can see different examples of this in our daily life. So, did you ever wonder about how the buckets of bulldozers are working? You will find a very good summary of hydraulics systems here. Here you can find the information;

  • What is hydraulics?
  • What are the general parts of a hydraulic system?
  • Applications of them.
  • Advantages and disadvantages.
  • Most encountered problems.
  • FAQs

What are the Hydraulic Systems?

The movement of parts and other elements is very important in industrial places. For example, they need to move heavy packages from the production line to the logistics section in a manufacturing area. So, there must be systems to move these loads between the lines.

There are different kinds of systems to move the loads between points. Also, one of the most important ones is the hydraulic system.

In these systems, we transmit the movement by the act of the fluids. Fluids can transmit pressure without any loss. Pascal’s rule is the dominant factor in hydraulic systems.

For example, think about a ram that is placed in a hollow cylinder. And this ram can move axially inside this cylinder. Also, we can pump fluid inside this cylinder. So, with this fluid that we are pumping inside the cylinder, we can axially move the ram. These are the general working principles of hydraulic systems.

Working Principles of Hydraulic Systems

If we take a look at the general working principles of hydraulic systems, there is a container that contains the hydraulic liquid. The system uses this liquid to move the components.

The most important feature of these systems is, that the fluids are always incompressible. Also, the most common hydraulic fluids are special oils. If there is a use of compressible fluids, this system is a pneumatic system which is beyond the topic of this post.

Also, the most important component of a hydraulic system is the pump. The power of the pump comes from an electric motor. The pump regulates the fluid flow to the hydraulic system. So, the pressure and the velocity of the fluid increase with the pump.

In general applications, fluid passes through a filter. This filter is very important to purify the possible contaminants in the hydraulic system. They can be very harmful to the other parts of the hydraulic system.

And also, there is a pressure regulator that adjusts the total pressure of the fluid according to the needs. Furthermore, their regulators can automate with software. Also, the operator can adjust them. Pressure regulators have a pipe that sends the excess fluid to the container back.

At the inlet side of the hydraulic system, there is a valve that opens and closes to regulate the fluid inlet and outlet. So, there is an inlet pipe that comes from the pressure regulator. And also there is an outlet pipe that returns the outlet fluid into the container.

So, this is the most basic principle that how this system works.

Parts of a Hydraulic System

Parts of a hydraulic system.
Image Source: Image Source: Parr, Andrew – Hydraulics and Pneumatics – A Technician’s and Engineer’s Guide-Elsevier, Pg.5

So, you may understand the general working principle of a hydraulic system. To clarify it, we need to delve into the general parts of these systems.

Energy Source

The energy source or type of energy is a very important parameter of hydraulic systems. So, there are different kinds of energy sources and systems. Among these energy sources; electrical energy and fuel energy are the most common ones.

Electrical systems are very common in industrial applications. And in these systems, there is an electric motor that gives the triggering motion for the pumps.

Fuel systems are also very common in construction equipment. Because these machines are mobile systems. The most important examples of these systems are the bulldozers. The arm and bucket systems are works with hydraulic systems operated by an internal combustion engine.

Linear and Rotary Actuators

Also, actuator systems are very important in hydraulic systems. Actuators are the end-effectors of the hydraulic systems which consist of different kinds of mechanisms. Among the rotary actuators, electric and internal combustion engines are the most common ones.

There are linear actuators in these systems also. Cylinders are used as linear actuators which can transmit very high loads.

Fluid Containers

Some containers contain the fluid that we use in the hydraulic systems. There is a sufficient amount of fluid for all the systems in the container. Also, there are inlet and outlet hydraulic pipes in this container. These pipes are linked with the other elements of the system.

So, this container must have excess fluid which can be spare in the event of fluid loss from the system.

Pumps in Hydraulic Systems

Above all, the pump is one of the most important parts of hydraulic systems. In general, we use pumps to transfer the fluid. So, they do it by giving mechanical energy to the fluid. Also, we are using pumps to pressurize the fluid to use in the hydraulic actuators.

The pump is directly connected to an electrical motor. There is a shaft that transfers the electrical power to the pump. So, fluid is pressurized to use in the hydraulic systems.

Pressure Regulators

The pressure of the hydraulic fluid is very high due to the pump. According to the need for hydraulic force or pressure, the pressure regulator regulates the very high pressure to the intended levels. So, there is an excess fluid outlet at the pressure regulators. The excess fluid pipe is directly connected to the containers.

Furthermore, the pressure regulators can be controlled by software or manually. The operator of a hydraulic system can control the regulators. Also, there are automated systems that control the regulators.

Control Valves

At the inlet section of the hydraulic cylinder, there is an on and off valve. This valve controls the inlet and outlet fluid to the system. Operators control the control valves to control which amount of motion is desired.

So, there are inlet and outlet pipes on these valves. The fluid inside the hydraulic cylinder is returned to the container. Also, fluid comes to the cylinder from the inlet pipe.

Filters in Hydraulic Systems

Also, filtering is very important in hydraulic systems. There can be contaminants in the hydraulic fluid. In each phase and cycle, this fluid is filtered before the pump. So, we prevent the possible contaminants in the fluid. So, these contaminants can be very harmful to the other parts of hydraulic systems.

They use different kinds of filtering systems in hydraulic systems. According to the type of the fluid, the type of the filtering system changes.

Pipes and Tubes

These are also very important parts of a hydraulic system. They are the connection between the parts of the hydraulic systems where they transfer the hydraulic fluid. So, these pipes and tubes must withstand very high fluid pressures. Because this pressure make the mechanical work.

Also, these pipes and tubes must be flexible enough to not prevent the movements of the parts. If you look at the general pipes and tubes of these systems, they are very durable and flexible.

Hydraulic Cylinders

These cylinders are the actuators that produce the motion of the tool. If there is a fluid increment in the cylinder, we obtain a positive motion. Also, if the system takes fluid from the cylinder, we obtain a negative motion from a hydraulic system.

Hydraulic Fluids

In hydraulic fluids, we are using Pascal’s law of incompressible fluids. So, hydraulic fluids are the incompressible fluids that we use in hydraulic systems. But in general, we are not using a hydraulic fluid directly in these systems.

These fluids are generally oils. The machinery part can work with oils because of the lubrication characteristics. This is a very important thing for the system parts for smooth working.

Applications of Hydraulic Systems

Hydraulic systems are very common in the industry and in daily use. So, there are various kinds of applications that we use these systems. Here we listed some applications that people use these systems commonly.

Automotive Brakes

Automotive brake.
Imgae Source: Wikimedia.

Maybe this is the most common application of hydraulic systems that people are using in their daily life. Automobile brakes are these systems. So, by pressing the brake pedal, the hydraulic fluid directly transfers this motion to the brake discs. And then, these discs make the same pressure on the wheels which makes the automobile stop.

Sometimes, there can be incidents where the brake fluid instantly discharges from the system. In this case, we dangerous state takes place. So, the brakes will not work. You need to make regular maintenance of your brake systems to prevent these kinds of incidents.

Bulldozer Buckets

Bulldozer bucket.

We are not using bulldozer buckets every time. But we can witness their use of them in the constructions in daily life. They are very strong machinery that can levitate the boulders without any difficulty. So, this power comes from a hydraulic system of the bucket system.

Unlike the other systems in machinery, the main power source of these systems is the internal combustion engines. The hydraulic pump is worked with the internal combustion engine. So, they are very powerful hydraulic machines.

There are lots of fluid regulators and valves in these systems. And the operator uses these valves and regulators to control the bucket systems.

Industrial Movers

Also in industry, there are lots of examples of hydraulic systems. In industries and manufacturing sites, there are different kinds of moving and transferring applications between the different sections. For example, we need to place the parts from a line to other lines. So, we use a basic hydraulic arm to do it.

Hydraulic systems are very powerful and very common such these applications.

Hydraulic Forklift Systems

If you ever witnessed that, forklifts are also very powerful machines that carry lots of loads. Also, these forklift systems are hydraulic. There is an internal combustion engine that rotates the hydraulic pump of the forklift system.

Also, the forklift system has only one motion. This motion is the up and down motion of the fork. So, there is no requirement for complex systems like bulldozers.

Truck Dumpers

A hydraulic truck dumper system.
Truck dumper.

Trucks are carrying tons of loads at their dumpers. And also the load and unload of these loads is very easy with these machines. For example, the truck dumper lifts and unloads the sand in the dumper. So, this lifting system is hydraulic.

This is also a very basic hydraulic system. There is a cylinder that fills with hydraulic fluid and dumper lifts. Also, you can hear the working engine sound while the dumper lifts. This means the internal combustion engine works the hydraulic pump.

Industrial Manufacturing Machines

There are also lots of manufacturing machines that use these systems. Because these systems are very powerful. Around these machines, one example is the pressing systems in plastic molding processes.

In these systems, there are two or three halves of plastic molds that are filled with molten plastic. So, the hydraulic pressing system presses the halves to fill the mold space with molten plastic. And holds the halves under pressure to make the plastic take the shape and solidify.

Hydraulic Presses

On Instagram or Youtube, maybe you see lots of kinds of viral videos about hydraulic presses that squeeze different parts. Also, people use them in different kinds of industrial applications.

And also in hydraulic presses, there are very basic systems that move the jaws of presses. You can hear the electric motor and pump sound while these presses are working in the videos.

Advantages and Disadvantages of Hydraulic Systems

Like all systems, there are advantages and disadvantages to hydraulic systems. Before the application of these systems, we need to consider these advantages and disadvantages. So, you need to be aware of the general advantages and disadvantages of these systems.


  • One of the most important advantages of these systems is we can use different kinds of energy sources such as electrical motors and diesel motors.
  • The total energy costs of these systems are not high as other alternatives. Because they are working with conventional motors and actuators.
  • Also, one of the most important advantages of hydraulic systems is; that we can control very high pressures and forces with very good accuracy. Because of these features, the use of hydraulic systems is very common in lots of areas.


  • Also, the most important disadvantage of these systems is, that the accumulation of the fluid is somewhat hard. The accumulated fluid in the accumulator can lose its energy and pressure over time.
  • In general, hydraulic systems are working at low speeds. Because the injection of fluid inside the cylinder can take time.
  • Also, another important disadvantage is the leakage problem. We are using hydraulic fluids and lots of parts and pipes. There can be fluid leakages around the hydraulic machinery parts. This lead to the loss of efficiency of the system. Also, this is an additional cost for the maintenance of the system.

Most Common Problems with Hydraulic Systems

While we are working with the hydraulic systems, we encounter these general problems. These problems can result in additional costs to the operation of these systems.

Fluid Leakage in Hydraulic Systems

Maybe fluid leakage is the most common one among others. Because there are lots of parts that fluid transfers between them. So, fluid leakages can take place.

This problem may lead to the loss of efficiency in hydraulic systems. So, we need to add additional fluid to the system. This is a cost.

Also, we need to repair the sealing problems on the pipes and tube connections. This is also a very important operational cost.

Pump Breakdowns

Maybe the hydraulic pumps are designed to withstand very high fluid pressures. But, once the pump breakdowns, the hydraulic system becomes inoperative. This is because the pump is the main source of the pressure and force of the fluid.

The maintenance of the power systems of these systems is an additional cost. So, you need to consider the regular maintenance of the pumps.

Filter Clogging

Regularly, we need to clear the filter of the hydraulic systems. Because they get clogged over time. If the filter clogs, the fluid supply will be clogged to the hydraulic system. Also, there will be lots of contaminants that can damage the system.

For lots of the systems, cleaning filters is very simple. Also, you need to change the filters regularly. Because they lot their efficiency over time.

High Fluid Temperature in Hydraulic Systems

This can be a also problematic issue in these systems. So, there can be additional fluid cooling systems on hydraulic systems. If the temperature of the fluid rises, it may damage the parts of the system in a bad way. So, we need to monitor the fluid temperature in these systems.

Water Contamination in Hydraulic Systems

Water contamination can take place in hydraulic systems. You can understand the water contamination problem in these systems by looking at the color of these systems. So, the hydraulic fluid will take a milky color.

Water can cause very big damage to the efficiency of the system. The lubricative property of the oil will decrease because of the water. Also, high-pressure water can cause corrosion and pit on the machinery parts.

To prevent water contamination, you need to make sealing maintenance of the hydraulic system. Because water can infiltrate the system from loss of sealing.

Incorrect Hydraulic Fluids

You need to use the correct fluids in the these systems. The fluids change according to the system. The properties of fluid affect the efficiency and the lifetime of the hydraulic system parts. So, be aware of the use of the recommended hydraulic fluids in that machinery.

Conclusion about Hydraulic Systems

As you understand above, hydraulic systems are very important for today’s technology. We are utilizing them in different kinds of industrial and daily applications.

They can move very high loads. And they can operate with very high forces. So, these systems are very common in heavy-duty operations.

Also, around the applications of these systems, brakes, movers, forklifts, and others. The working principles of some of them may be complex and some of them are not.

Like the other systems, hydraulic systems have advantages and disadvantages. We need to consider them correctly to apply them in different applications.

Also, you need to be aware of the general problems of these systems. So, you will apply the maintenance of the parts to prevent these problems.

Do not forget to leave your comments and questions below about these topics.

Your precious feedbacks are very important to us.

FAQs About Hydraulic Systems

How to maintain a hydraulic system?

Firstly, you need to know the general problems of a hydraulic system. According to these problems, you can work with a maintenance team.

What are the disadvantages of hydraulic systems?

The most important disadvantages, the moving speeds are low. But, these systems can carry lots of kinds of loads and forces at low speeds.

Where the hydraulic systems are used? 

There are lots of applications that we use these systems. Among these applications; are automotive brakes, hydraulic presses, industrial machinery, forklifts, bulldozers, truck dumpers, and so on. You can find much more application examples of these systems.

Why hydraulic systems are used?

Because they provide very strong and heavy-duty works with very basic systems. You can move tonnes of loads with that system. Also, it provides various moving applications thanks to these systems. You can convert a rotational movement into the movements of a bulldozer bucket with these systems.

What are the advantages of the hydraulic system?

Among the advantages of these systems, they are very powerful. We can control very high loads, forces, and pressures with these systems. Also, we can use various energy sources to operate the hydraulic systems. For example, some systems use electric motors and internal combustion engines.

How to improve a hydraulic system?

If you want to use your system in the most efficient state, you need to make regular maintenance to prevent general problems. These general problems; hydraulic fluid leakages, water contaminations, filter vlogging, pump and power source breakdowns, and so on.

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