Around three-quarters of all hydraulic system failures can be attributed to contamination issues. Contamination of hydraulic fluid can occur when, for example, fluid is topped up, from the friction between parts and elements during general use, from older parts as they wear out, or are replaced, even from the manufacturing process itself.
There are many other circumstances in which contamination leads to fluid power system problems. To prevent these time-consuming and costly problems a filter is an essential part of any hydraulic system.
What Are Hydraulic Filters?
Hydraulic filters remove contaminants from the fluid power system. By reducing the amount of contaminants in the system a suitable and effective filter can keep maintenance costs lower, prevent system failures and keep your hydraulic system in tip-top working condition for longer.
A suitable filter will need to be the correct size and type for the system pressure, flow rate, and environment and will need to be well maintained.
Types Of Hydraulic Filters
Situated inside the hydraulic reservoir (but under the minimum fluid level) suction filters are attached directly to the suction lines.
- Pros: easy maintenance.
- Cons: suction filters are not always suitable for systems with variable volume and their position means they don’t protect from contamination from general use/wear and tear.
Usually, these are spin-on disposable canisters and are situated in the system return lines. Low-pressure filters are suitable for hydraulic systems with pressure up to 150psi.
- Pros: economical with up to 500 hours of use. Also function as reservoir breathers. Pressure indicators show when replacement is required.
- Cons: lifetime halved (250 hours) for high contaminant environments (foundries etc).
Tank Top Return-Line Filters
Position on top of the hydraulic tank enables easy access for maintenance. Tank top return line filters are also longer, allowing for better control of aeration and flow.
- Pros: efficient, with increased contaminant capture. Suitable for most types of hydraulic systems.
These are in-line filters that protect the most sensitive parts of the system. They are suitable for hydraulic systems with between 500 and 1200psi and with flow rates of between 50 and 425 gallons per minute.
- Pros: good for a wide range of applications. Environmentally friendly options are available.
- Cons: easy to overspend on a higher spec filter than you need.
Like medium pressure filters, high-pressure filters are situated in line to protect the components downstream from the pump. They can withstand anywhere from 1200 to 7000psi and can contain components of the strongest, most durable materials such as steel bowls and iron filter heads. These filters can be used for the toughest jobs.
- Pros: customisable options, high strength housing, port sizes, and performance.
- Cons: high spec can equal high cost – seek advice for the best value for your needs.
We hope this information will help you to keep your fluid power system running efficiently to save you time and money. If you need any further advice in choosing the best hydraulic filter for your system then MCH Hydraulics will be happy to assist you, so don’t hesitate to get in touch.