Did you know that over 75% of hydraulic system failures are caused by... dirty oil? Metal shavings from worn cylinders, sealing debris, or even simple sand can destroy a brand-new gear pump or jam a precision distributor valve in a matter of hours.
Every system needs filtering, but throwing just any filter in a random location is asking for trouble. Where should you install the filter box to ensure your machine runs for years? BRhydraulic experts took a closer look at the three most popular types of hydraulic filters. Find out which one you need for your project!
1. Suction Filter (The Beginning) – Protection of the Pump Itself
The suction filter (often in the form of a metal dragon) is mounted inside the oil tank or on the hose between the tank and the pump.
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Task: It is to catch the largest debris (e.g. screws, large filings, pieces of tow) before they fall into the pump and tear its gears.
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Advantages: Directly protects the heart of the system (the pump). It is usually very inexpensive.
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Disadvantages and risks: It must have a relatively large mesh (often 90-125 microns). If you install a suction filter that's too fine or forget to clean it, the pump won't be able to draw oil. This will create a vacuum and cavitation (exploding air bubbles), which will destroy the pump faster than the dirt itself!
2. Return Filter (Drain Line) – Most popular choice
This is an absolute standard on most agricultural machinery (Tura, balers) and log splitters. It is installed at the very end of the system , just before the oil enters the tank (e.g., after the distributor).
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Task: Captures all contaminants that arise during machine operation (e.g. wear-and-tear seals in cylinders) before they reach the general pool of oil in the tank.
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Advantages: Oil returns at very low pressure, so these filters have thin housings (spin-on "cans," similar to car oil filters). They are inexpensive, extremely easy to replace, and can be very dense (10-25 microns) because there's no risk of choking the pump.
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The golden rule: Choose a return filter with a flow capacity at least 30-50% greater than your pump's capacity! (If you have a 40 l/min pump, buy a filter with a minimum flow rate of 60 l/min to avoid resistance.)
3. Pressure Filter (Right after the pump) – Armored Protection
The most expensive, but most professional option. This filter is installed on the high-pressure line , directly after the pump and before the manifolds.
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Purpose: Captures the smallest particles (even 3-10 microns). If the pump suddenly seizes and grinds up inside, the pressure filter will absorb all the filings, protecting the exorbitantly expensive manifolds and valves installed further down the line.
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Advantages: Absolute protection for highly sensitive systems (e.g. in advanced forestry machines with proportional valves).
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Disadvantages: Because it must withstand pressures of 200-300 bar, its housing is a large cast iron or steel block. It is many times more expensive than a return filter.
Summary: What to choose for your project?
For simple workshop systems, splitters, or front loaders, the optimal and most economical solution is to combine a simple suction strainer (strainer) in the tank with a good return filter (spindle) on the downstream side. Don't risk the life of your pump! At BRhydraulic, you'll find a full range of strainers, housings, and complete assemblies. hydraulic filters tailored to each flow. Complete a safe operating system and enjoy years of trouble-free operation.
