The Use of Fire-resistant Synthetic Lubricants (HFDU) For High Pressure Die Cast Machines’ Hydraulic System

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In the preceding dissertations, the pros and cons of using of Mineral Oils and Water-Glycol Solutions for High Pressure Die Cast Machines were tackled, and both were given consideration as viable options.

high pressure die cast machine

image source: aluminum insider

HFDU oils, synthetic and fire-resistant, presents itself as possibly the technology that provides the best balance between performance (lubrication), and fire-resistance, albeit at a higher unit cost.  Essentially formulated from both organic and inorganic esters, plus additives, HFDU oils are anhydrous, or non-water containing.   In general, HFDU fluids, especially as compared to mineral oils and water-glycol fluids, exhibit the following properties,

  1. Higher Viscosity Index – thus, providing a wear-reducing lubricating film despite elevated operating temperatures,


  1. Excellent Rust and Corrosion Protection for both ferrous and non-ferrous metals – performing at par with mineral oils, and significantly better as with HFC fluids,


  1. Improved Pump Protection – as signified in pump wear tests, such as with the Vickers Vane V104C test

  1. Stronger Resistance to Oxidation – field experience has proven oil lifetimes that is 4 to 5 times longer than with competing technologies. This is due to HFDU’s higher resistance to the formation of acids which accelerate oxidation.


  1. Can operate at pressures up to 400 bar, and at designed pump speeds, unlike with the lower pressure and speed ratings of HFCs


  1. Fire-resistance – while not as fire-retardant compared to the water-based HFCs, the fire-resistant properties of most commercially available HFDUs are sufficient to pass Factory Mutual’s (FM) ratings on fire-resistance, a testament to HFDUs safety features.


In handling HFDUs however, ensuring that there is minimal water contamination is imperative, as the excessive moisture reacts with the HFDU components to form harmful acids.  As a rule of thumb, moisture of 2,000 ppm is established as a maximum limit.   Solid particulates need to be controlled also to ensure optimum performance, wherein NAS Class 9 is considered as the upper limits.

maximum particles

For more information on HFDUs, one is encouraged to view the white paper of Quaker Chemical’s Ronald Knecht —

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