A practical investigation of wear in piston pumps operated with HFA fluids with different additives

This paper examines the use of water-based hydraulic fluids in hydraulic pumps, Four different types of HFA fluid are reviewed in terms of properties and usage. In a research programme, two principal fluids, a HFA micro emulsion and a HFA solution, were evaluated in relation to their wear protection capability in a short-term test procedure, and their operational behaviour and confirmation of the short-term test procedure in a long-term test. The differences between the fluids are mainly in terms of wear of the test pumps. It is concluded that a performance standard similar to oil-based fluids has not yet been reached.