ERIKS filtration supplier MP Filtri UK respond to some commonly asked questions surrounding solid contaminants and how to keep your hydraulic fluid as clean and efficient as possible.
According to MP Filtri's technical team, 6 simple routines must be followed in order to minimise the chances of your hydraulic equipment suffering costly, premature component failures and unscheduled downtime:
- Maintain fluid cleanliness; ISO 4406 /NAS 1638/AS4095 Revision E
- Maintain fluid temperature and viscosity within optimum limits
- Maintain hydraulic system settings to manufacturers' specifications; eg ISO/NAS/AS4905 cleanliness for components, pressures and operational criteria
- Schedule component change-outs before they fail, Life of Component
- Follow correct commissioning procedures – with flushing and start up procedures
- Conduct proactive analysis. Regular monitoring, replacement of filter elements, daily and/or weekly inspection.
How can I limit solid contamination from entering my system?
Good housekeeping practices are essential. Below are a few steps you can take to make an immediate difference.
- Pre-filter your new or used oil before placing into or returning back to the tank.
- Have a dedicated fill point for the reservoir.
- Fit good quality breathers which are suitable for the application. At least 3 micron or better.
- Regularly replace the air-breathers, especially in harsh environments
How clean is clean?
The answer to this question varies from customer to customer, depending on their requirements and system conditions. What can be said is that the decision to control contamination is normally based on the sensitivity of the components within the process (e.g. servo valves and actuators). This information can also be found on MP Filtri's website.
One of the main things which is overlooked in the industry, is scale of cleanliness we are trying to control and measure. This is important to consider as it may change the way you choose to use your data to get a more realistic picture of system conditions over time.
To eliminate all contaminants below a certain size is extremely difficult when you consider all the possible sources of contamination surrounding the system. Care should always be taken to select the right equipment and use suitable statistical methods when evaluating data, making decisions and taking action.
What are the predominant types of contamination in my hydraulic system?
This can vary considerably depending on the type of system and installation, but below are some typical types of contamination. By looking at the certain types, conclusions can often be drawn as to where the contaminant may be entering the system. Steps can then be taken to reduce the effects of such a contaminant.
- Metallic — both ferrous and non-ferrous
- Silica (dirt, dust)
- Filter fibres
- Bacteria colonies
What effect does particulate contamination have on my system?
Contamination can induce excessive stress on system components such as pumps and valves as well as potentially clogging orifices, nozzles, and jets.
Below is a list common complaints’ associated with un-suitable fluid condition:
- Mechanical wear
- Clogging of nozzles, orifices and valves
- Loss of protective coatings on components
- Increased operating temperatures
- Change in fluid compressibility
What factors can effect particle distribution & concentration within my system?
Unlike laboratory conditions, real world applications are constantly changing. As a system operates, contamination is generated and needs to be controlled. It is physically impossible to achieve 100 per cent efficiency in any given system. Some particles will always get through filtration. This is one source of variation.
For more information or technical support please contact your local ERIKS Fluid Power Application Engineer on 0845 006 6000.