How to Choose the Right Hydraulic Filter for Your Equipment

Contamination control through filtration is essential for all hydraulic subsystems. Dirty hydraulic fluid can cause costly damage to components. Knowing the performance requirements of your application is critical for sizing a filter correctly. These must-knows will help you select the right hydraulic system filters for your equipment. It will lower operating costs in the long run. 


Many hydraulic filter suppliers VA provide graphs showing the expected pressure drop at various flow rates, but a variable added needs to be included as the fluid temperature. If you’re a new equipment owner, the best approach is to use synthetic oil to maintain its viscosity across a wide temperature range and provide maximum protection for critical hydraulic components. It will save you money over the lifetime of the machine.

The next important piece of information is the pressure in the working system. It will help designers choose a filter that can withstand that anticipated pressure without collapsing, losing its integrity, and potentially damaging the entire hydraulic subsystem. It also helps ensure the process fluid, filter media and seal material are compatible. The wrong match will lead to leaks and major contamination problems.

Pressure Drop

Choosing the right hydraulic filter for equipment depends on several factors. Knowing what to look for will help designers and maintenance teams select the best filters to protect hydraulic subsystems from damage. Understanding the fluid’s viscosity is an essential consideration for filter sizing. Ignoring this aspect may lead to the use of incorrectly sized filters, which will increase operating costs, result in high-pressure drops, and necessitate a larger footprint. It can also result in premature tripping of the filter’s clogging indicators.

Most filters include a bypass to allow contaminated fluid to flow around the plugged or clogged filter element and prevent system failure. However, monitoring the filter’s pressure drop is important to know when to change it. Changing filters at the correct time can extend the life of piston pumps, motors and gear pumps.

Flow Rate and Pipe Size

Hydraulic filter selection begins with understanding your system’s working pressure. Pressure filters and return line filters require a pressure rating that matches the pressure of the system pump to ensure proper operation. A filter not rated for pressure can collapse and leak debris into the hydraulic system. Flow rate is also important to consider. A higher fluid viscosity will require a larger filter to maintain an acceptable pressure drop.

In addition, the pipe size must match the filter type. Using a too small tube increases fluid velocity, creating temperature problems and wasting energy. A too large tube is expensive and creates a back pressure problem that can destroy seals and cause leaks in the hydraulic system.

Fluid Viscosity

Every hydraulic fluid has a temperature range where it performs optimally. Outside that range, its properties can change significantly. It can lead to inefficiencies or even system damage. A multi-viscosity mineral oil, for instance, offers better performance across a wide operating temperature range than monograde mineral oils. It allows free equipment operation in cold temperatures and more efficient performance when the hydraulic system reaches higher temperatures.

The right hydraulic filter can help ensure the system operates within a safe temperature range. It is essential to avoid unnecessary equipment downtime and shortened machine life. It can also minimize the risk of particle buildup in critical areas, sludge formation and component seizure. It will help extend the life of the machine and reduce maintenance costs.

Cleanliness Requirements

It’s important to consider cleanliness requirements. It’s true for new systems or those that undergo significant overhauls. When the fluid isn’t clean, it can cause problems like sludge buildup or component seizing. In addition, the contaminants can wear away at precision parts, causing unplanned downtime and costly repairs. Hydraulic filters trap contamination particles and remove them from the fluid stream, protecting downstream hydraulic components from damage. It’s important to use pressure, return line, and bypass filters rated for the system’s operating pressure and ISO code. It’s also essential to flush the system before putting in any oil, and it’s always best to use clean fluid. It will minimize the risk of contamination and keep your equipment running smoothly.