August 5, 2021

Hydraulic Fluid Filtration

Hydraulic Fluid Filtration

As hydraulic technology has advanced over the years, keeping your hydraulic fluid free from impurities and contaminants is more important than ever before. With tighter tolerances and ever-increasing pressure loads, contaminated hydraulic fluid can have tremendously detrimental effects on your equipment.

That’s why having the right filtration equipment for your hydraulic systems is so critical. These filters remove many of the contaminants that could otherwise compromise the performance of your system or cause significant damage to your equipment.

However, not all hydraulic fluid filtration systems are the same. By familiarizing yourself with the various types of filtration available, you can be sure that your hydraulic machinery will keep working at its best.

Hydraulic Fluid and Contamination

hydraulic fluid contamination during production

As you know, hydraulic fluid is the lifeblood of hydraulic systems. Hydraulic fluid plays a critical role in the operation of these machines, performing four main functions:

  • – Providing the primary medium for power transfer
  • – Creating a pressure barrier by forming seals between metal surfaces
  • – Regulating temperature by cooling mechanical components
  • – Lubricating the metal surfaces of the hydraulic machinery

Hydraulic Fluid as a Lubricant

Of all these roles, lubrication is the most often overlooked — but it’s also one of the most important functions of hydraulic fluid. As component parts move in close proximity to each other within hydraulic equipment, the fluid provides a thin cushion between them, preventing components from rubbing against each other. Friction can quickly result in decreased performance and early equipment failure.

This is especially true for newer machinery, which can contain clearances of only 1 to 2 microns. These components are typically very sensitive. Maintaining that slim clearance is necessary to keep them working accurately.

Fluid Contaminants

There are a number of different kinds of contaminants, each of which can negatively affect your hydraulic systems. However, when it comes to filtration systems, the primary target is particulates.

As you use your hydraulic equipment, you’ll encounter several different kinds of particulate contamination in your hydraulic fluid. These particles are often too small to see, measuring less than 40 microns in size. However, that’s more than enough to cause problems with your equipment, where tight tolerances are increasingly common.

Dirt, sand, grit, and other particles often make their way into your equipment over the course of operation. No matter how well your components are sealed, there’s almost always some way for these particles to make their way into your system — including through the hydraulic fluid itself.

Other particles are created by the natural function of your equipment. Over time, seals begin to degrade, and components will occasionally come into contact with each other, generating small particulates that enter your hydraulic fluid. This effect tends to accumulate by a magnitude:  These particles lead to the creation of more wear and more particulates.

Finally, it’s not uncommon to encounter particulates remaining from the process of manufacturing the equipment. Luckily, this contamination can be easily removed by flushing the equipment before using it — and by ensuring that you add the correct hydraulic fluid filtration system to your equipment.

The Importance of Hydraulic Fluid Filtration

hydraulic contamination

When it comes to particle contamination, the first step is exclusion. The more particulates you can keep out of your system, the less chance there is that your system is going to suffer degraded performance or damage. 

However, as stated before, even the best-sealed system can’t keep all external particulates out, and the day-to-day wear and tear of operation will inevitably lead to the generation of particles. That’s what makes hydraulic fluid filtration systems so vitally important.

As particulates enter your hydraulic fluid, they can start to cause problems almost immediately. Large particles can end up in the tight spaces between components, compromising the ability of the hydraulic fluid to provide proper lubrication. This can lead to the generation of more particles. In more severe cases, it can cause parts to seize or jam, which usually leads to expensive and time-consuming repairs.

Particles can also clump together in the fluid, creating sludge or precipitates. These substances can cause even more problems, gumming up the operation of moving components and potentially clogging nozzles, jets, and other parts that rely on suction.

When these particles become trapped in tight clearances, they can wear away at the components, acting like sandpaper and grinding away at the surface of bores, pistons, valves, and other vital parts. This damage can quickly lead to severe mechanical problems, along with the need to replace parts prematurely.

Hydraulic fluid filtration systems are designed to strain out the vast majority of these particles, keeping them from entering vulnerable areas of your hydraulic systems. While filters can’t remove every single particle from your hydraulic fluid, the amount they do trap can help to ensure that your equipment lasts as long as possible, while reducing the need to replace the hydraulic fluid in your system.

How Hydraulic Fluid Filtration Works

changing hydraulic filter

On the most basic level, hydraulic fluid filtration involves passing the fluid in your equipment through a strainer, typically made of fiberglass or cellulose. As the fluid passes through the filter, larger particles become trapped, while the fluid continues to pass through. The filters continue to accumulate particulates until they become saturated, at which point they’re either cleaned or replaced.

Of course, there’s more to it than that. With the increased demands of modern hydraulic systems, keeping your hydraulic fluid clean is more important than ever before. 

There are several different types of filters, and most systems will incorporate several different strainers throughout their system to increase the effectiveness of their hydraulic fluid filtration.

Suction Filters

These filters help to protect your hydraulic pump from particulate damage. Located either externally or internally, suction filters are positioned at the inlet to the pump, preventing particles from not only moving into the pump but also from being further distributed throughout your system.

Return Filters

As your fluid returns to the reservoir, it passes through at least one return filter, which catches any particles generated by the working components. This prevents particle contaminants from making their way into the reservoir and re-entering the fluid circulation.

Pressure Filters

Located downstream of the hydraulic pump, pressure filters trap particulates that make it into the pump. These are especially valuable for protecting sensitive components.

Duplex Filters

These filters perform as pressure and return filters, with at least two separate filter chambers. This allows an operator to change one filter without interrupting the flow of hydraulic fluid, meaning that they won’t have to stop production to change a filter.

Off-Line Filters

Off-line filters are quickly gaining in popularity as a hydraulic fluid filtration option. These filters work independently of the primary hydraulic unit. They include a separate pump and plumbing hardware, where they can pump fluid from the reservoir through the filter and return it directly to the reservoir.

Maintaining Your Hydraulic Fluid Filtration System

While ensuring that you have the right hydraulic fluid filtration equipment installed in your hydraulic system is the first step, the most important thing is to maintain those filters over the course of normal operation.

Here are the maintenance steps that you’ll need to take to make sure your filtration system keeps working.

Start with Clean Fluid

Hydraulic fluid filtration systems aren’t designed to restore fluid that already has a high concentration of particles. The filters would quickly clog, and you’d be left with a new problem.

Instead, filters are intended to preserve fluid, which means you’ll get the most out of your filters by starting with fresh hydraulic fluid.

Change or Clean Your Filters

As particles become trapped in your filters, the volume of fluid that can pass through will continue to decrease. This leads to increased pressures in your system, and that can lead to a number of problems, including lowered performance and pump damage.

Most newer filters have an indicator, although some are monitored electronically by the equipment. In any case, you should follow the instructions from the manufacturer to make sure that your filters don’t become too clogged. Your manual will also tell you whether your filters should be cleaned or replaced.

Keep Records

No matter what maintenance you’re performing on your hydraulic machinery, you should keep accurate notes. This is especially true for your hydraulic fluid filtration system. 

Typically, you’ll only notice there’s a problem with a filter when something else goes wrong, so staying on top of filter maintenance is vital. With clear records, you’ll ensure that your filters are working at peak efficiency.

Benefits of Hydraulic Fluid Filtration

Effective hydraulic fluid filtration can protect your system against the damage that results from particulate contamination. Not only will this help you to extend the life of your equipment, but it can also ensure that you don’t lose time and productivity as a result of repairs. Lastly, it can save you from the cost of constantly having to replace your hydraulic fluid. With the right filtration system, you can keep your hydraulic equipment running smoothly for years to come.

The MAC Hydraulics Difference

At MAC Hydraulics, we’re ready to help you find the right hydraulic fluid filtration equipment for your system. Contact us today to speak with one of our experts, and we’ll make sure your hydraulic system is working its best.

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