Hydraulic Systems: Everything You Need to Know

Hydraulic systems represent some of humanity’s oldest and most reliable forms of technology. They are used for a massive variety of applications, come in many shapes and sizes and can be found operating in almost all facets of modern life.

These systems have an invaluable role to play in every setting from vehicles and shopping malls to factories, warehouses, construction sites, mines and chemical plants. They seem to be everywhere and are so intimately integrated into various aspects of modern life that, often enough, we don’t even notice them going to work everywhere around us.

Of course, if you work with hydraulic systems every day, which many of us do, you have an understanding of where they are used and what they are used for.

To expand on that information, this article aims to discuss the topic of hydraulics in detail. We will explore exactly what they are and where they are used, what type of systems exist and how they work, the many benefits and few drawbacks associated with using them, as well as providing tips on how to pick the best possible hydraulic suppliers for your needs.

So, let’s get started by taking a closer look at what these systems are exactly, and how they work:

What are Hydraulic Systems?

What exactly are hydraulic systems? You likely have at least a vague understanding of what they are, since they can be found operating through almost all aspects of our lives. But for the sake of clarity, let’s stick to a detailed definition:

In a nutshell, hydraulic systems represent a type of hydrostatic drive system. It makes use of highly pressurised hydraulic fluid to create pressure in the system at levels that are concentrated enough to generate immense amounts of power by transferring energy from built-up differences in pressure.

This differs in greatly from other systems such as electrical motors, which do the same thing by harvesting kinetic energy.

This energy can thusly be used in a range of applications, from powering brake systems in cars to providing useable energy to heavy-duty machines.

How do Hydraulic Systems Work?

The beauty behind the power of hydraulic systems is their sheer design simplicity. They are able to produce so much energy for a vast collection of applications, all through a very simple yet elegant design.

They simply use a pump to push their internal hydraulic fluid through the existing system. As they do this and pass through valves and hydraulic cylinders that make up part of the pressurised system, it converts hydraulic energy in the fluid into mechanical energy.

In addition to this, these systems need control over the flow of the fluid in the system to ensure that pressure is only applied when needed, and so the various valves in the system also work to redirect the flow to subsequently relieve pressure levels when required.

While being remarkably simple in their functionality and operation, the implications and applications of such systems form an essential part of nearly all industrial applications, as well as those that we can find in our daily lives.

Let’s take a moment now, to explore the different types of hydraulic systems available to those who use them.

Types of Hydraulic Systems

Here we will explore the two major types of hydraulic systems available. These are open-loop and closed-loop hydraulics:

Open Loop Hydraulic Systems:

Open-loop systems are better suited to applications that require lower levels of pressure since they typically operate at pressures below 3000psi. In these systems, valves are required to change the direction of the fluid and operate without the need for continuous pressurisation of the system.

Examples of these types of systems may include compressors, pumps, boilers, heat transfer systems and turbines.

In each of these settings, the operation takes place under lowered pressures when compared to those used to power industrial machines, for example, and for the most part, only require a unidirectional flow of the hydraulic fluid.

Closed-Loop Hydraulic Systems:

By comparison, closed-loop hydraulic systems are designed to operate under staggeringly high levels of pressure, making it well suited to applications where pressure rises above 3000psi.

They provide enhanced control thanks to the ability to change the flow of hydraulic fluid in the system without the need for additional valves.

Additionally, closed-loop systems require continual pressurisation to operate effectively, making them well suited to use in mobile applications of a hydrostatic transmission.

Because of this, these systems are commonly used for combustion engines and reciprocating air compressors, where extreme levels of pressure are required for optimal operation.

Benefits of Hydraulic Systems

Next, let’s take a closer look at some of the top advantages to using a hydraulic system compared to others.

These benefits include, but are not by any means limited to, providing exceptional mechanical power, working with extreme accuracy, and enhancing the efficiency of whatever it is applied to:

Incredible Power from Pressure

Hydraulic systems are able to support immense amounts of weight thanks to their pressurised design.

Of course, there are other solutions that can work with extreme weight just as well, but none of them is able to do it with the simplistic, compact design offered through the use of hydraulics.

Also, unlike many other systems, hydraulics can provide consistent force even when speeds are lowered substantially; making it a remarkably energy-efficient approach.

Precision & Accuracy

These systems are also able to provide exceptional operational control and accuracy thanks to their ease of operation.

They transmit power, start and stop with a simple touch of a button with immediate effect, which isn’t always the case with related systems.

This, in turn, gives operators incredible amounts of control with regards to their operation.

This is particularly the case in closed-loop hydraulic systems since they allow the flow of hydraulic fluid to be changed from negative to positive or vice versa at a moment’s notice.

Enhanced Efficiency

The biggest advantage of these systems comes in the form of sheer operational efficiency.

This is because of their ability to handle extreme levels of mass as mentioned above, coupled with their impressively simple design.

When compared to mechanical systems that are used to perform the same or similar functions, their weight ratio, compact design, and complete lack of moving, mechanical parts, accounts for their unrivalled efficiency and effectiveness.

Low Maintenance Needs

The fact that these systems are made up with fewer moving parts than mechanical systems, leads to a reduced need for maintenance by comparison.

This is because moving parts, like those found in mechanical systems, produce friction on each other when in operation. As this happens, the parts will gradually wear down and become ineffective over time.

This isn’t a concern for hydraulic systems despite the immense levels of pressure they operate under since they are elegantly designed to not need assistance from any moving parts.

This means, that even though maintenance will eventually be a concern for operators, the need for it will be greatly reduced when compared to mechanical ones.

Safer Operation

Let’s talk about another advantage brought about by this simplistic design; that of the safety of the operators who are using these systems.

Even though they operate under immense pressures (the dangers of which we will get to in a moment), they have no moving parts which may otherwise result in some fairly severe injuries being sustained when operated without paying attention.

This makes hydraulic systems a safer bet by comparison.

Drawbacks of Hydraulic Systems

As it is with any type of technology, there are, of course, a few drawbacks to using them. However, when operated with care, these can often be easily negated with the correct operating procedures and careful attention to correct maintenance in place.

Leaks can be Difficult to Fix

Hydraulic systems rely on carefully controlled levels of pressure in order to function correctly and safely.

Unfortunately, the constant presence of extreme pressures can put a lot of stress on them in terms of structural integrity, which can lead to leaks from damaged hydraulic cylinders.

These can be difficult to pinpoint in some cases, which can make repairs a fairly complicated and lengthy affair.

Of course, with the careful operation, constant monitoring and the correct maintenance procedures in place, this can be completely avoided in most cases.

Exposed Hydraulic Fluid can be Dangerous

The contents that make up hydraulic fluid may differ somewhat, but in most cases, it is made up of a mixture of mineral oil or water.

Often, the fluid itself can actually be harmful to humans upon contact, since they may contain irritants or corrosive materials in some settings.

Since these systems are pressurised, the chance of incurring leaks is always there, which can make them dangerous to those who work around such systems when fluid leaks out of them.

Hydraulic Systems Operate Under Dangerous Pressure Levels

Hydraulic systems are dependant on extreme pressure levels for their normal operations, but this also presents a potential danger to those operating them, especially when such systems are poorly produced or maintained.

When the structural integrity of these systems are compromised, elevated levels of pressure can actually present a danger of explosion, which can cause untold damage to surrounding people, equipment, components and structures.

Once again, if these systems are used as directed, are manufactured to industry standards and are properly maintained, the chance of this happening is actually fairly slim.

Common Uses for Hydraulic Systems

With those nitty-gritty advantages and drawbacks out of the way, let’s take a closer look at how these systems are employed in everyday life.

This should serve as an example of why these systems are so widely used, and why they are considered important:

Powering Tools & Machines

One of the most commonly considered functions for hydraulic systems falls in the realm of heavy-duty industrial processes.

They are used to for everything from operating man-up machines to powering heavy-duty machinery and tools.

While mechanical and electrical pumps can be used to the same effect, they don’t offer the same in terms of compactness, safe use, ease of use, or even operational efficiency.

Cars, Planes, Trains & Ships

Almost all transport systems use hydraulics in one way or another.

From rudders on boats, braking systems on trains, buses and cars to operating the flaps on an aircraft, we wouldn’t be able to get around nearly as effectively or as safely as we do, if it wasn’t for the miracle of hydraulic systems.

Lifting People & Objects

Hydraulics are also invaluable wherever safe but the heavy lifting is a concern. From wheelchair lifts in homes, shopping malls and cars; right through to forklifts, cranes and commercial lifts, hydraulics are widely used everywhere from the industrial and commercial spheres, right through to residential ones.

Contact Sealtec Hydraulics for Details

With so much to account for when working with hydraulic systems, it is easy to see why the best results come from working alongside a professional supplier who can take your exact needs, budget and considerations into account.

Are you in the market to partner up with a hydraulic supplier with the experience and skill set needed to ensure that you get the most out of your system, no matter where it is used?

Be sure to get into contact with a representative from Sealtec Hydraulicstoday, or visit our website for more details on our range of specialised services and offers.

Leave a reply



+27 16 428 5190/1/2/3/4/5/6/7


(+27) 16 428 4197 (GENERAL FAX)
(+27) 16 428 5040 (SALES FAX)




3C Houtkop Road, Duncanville Vereeniging, Gauteng, South Africa GPS: 26 38'56"S 27 56'21"E


Monday to Thursday - 8:00AM till 16:30PM
Fridays - 8:00AM till 14:00PM
Public Holidays Closed

Please note for an urgent breakdown we are available 24/7

Barry Jacobs Senior (Managing Director)

082 478 6959

Barry Jacobs Junior (Sales Director)

083 654 5195

Jacque Jacobs (Technical Director)

082 825 6174

Fanie Campher (Sales Representative)

082 354 1703

Meiring Van Heerden (Sales Representative)

083 375 7338

Sealtec Logo