Suitability of Various Fluids with Hydraulic System

Viscosity

Chemical characteristics,

Chemical compatibility with each and every part of the system the fluid will be in contact with.

Any other parameter, depending on the proposed use.

Do not put open-ended questions, be specific, and the answers may be to the point.

I have an hydraulic pipe line with ... liquid at .. pressure, ... temperature, line material is.... can I use it with ... ?

or is it a homework?

Seal compatability, maximum pressure, seal compatability, maximum temperature, seal compatability, vapor pressure, seal compatability, flammability, seal compatability, toxicity/disposal, and seal compatability. Say, did I mention seal compatability?

If you are changing mineral oil of a certain viscosity to mineral oil of a different viscosity then, the only things you need to consider are the temperature impact on the system such as, flow through orifices, startup power consumption and filtration sizes.

If you are changing from mineral oil to a water glycol fluid of similar viscosity, if you don't clean the system first, you will end up with a gloopy mess. Also, it is more difficult to get heat out of water glycol so, cooling may be an issue!

If you are changing from mineral oil to vegetable oil, again, you would need to clean the system very well.

There are lots of combinations of possible change so it would be good to have more information on the proposal.

Then of course, there are issues of compatibility of seals (), pump and component life expectancy AND even, changing the MSDS (COSHH) data sheets for substances used (held) on site.

From:Tim Hawley Master Mech.

Hello mansilakhani,

Will the hydraulic system continue to be used for the same job? If so why create more work for your self. Only use what the OEM recommends. If you change the viscosity to a higher level you will change flow and all flow control valve will have to be opened. If the fluid is to thick you may reach the maximum flow of the flow control valves. Then you have a large can of worms. If the viscosity is to light the opposite will occur. Changing to a coolant or different type of fluid will require a lot of work. Most important there are several different types of filters and you will have to flush the whole system and spec out a new filter system. If the filter is the wrong type you will have no pressure on the output side and little flow.

Let me know the answer to my first question, Thank you in advance,

Tim

hello,

I would say, yes, the system will be cintinued to be used for same job.