Water glycol Fire Resistant Hydraulic Fluids

Water glycol - fire-resistant hydraulic fluid

Water glycol fluids have proven to be an excellent fire-resistant hydraulic fluid option. The fire-resistance of these fluids depends upon the vaporization of the water and the smothering effect of the steam. The other performance characteristics important to these fluids are viscosity, lubrication quality, operating temperature range, corrosion resistance, system compatibility and fluid maintenance. Excellent fire-resistance coupled with good cost and performance makes water glycol fluids the right choice for many industrial applications.

Water glycol fluids consist of a solution of water, ethylene or diethylene glycol, a high molecular weight polyglycol and an additive package. The water-to-glycol mixture typically contains 38 to 45 percent water. These fluids usually contain red or pink dye to aid in their identification. With water in the fluids’ formulation, evaporation is ongoing and upper operating temperature limits must be considered. Checks must be made periodically of the water content. The fluids’ typical operating temperatures should be kept below 150°F.

The polyglycol is a water-soluble polymer thickener, which can be formulated to cover a wide range of viscosities. The resulting viscosity-temperature properties are Newtonian and give water glycols good low-temperature cold-start pump wear protection as well as minimizing cavitation. The additive package imparts corrosion resistance, metal passivation, seal and hose compatibility, oxidation resistance, antimicrobial properties and antiwear properties. With a density of about 1.0, mineral oil contaminants may float on the fluid surface and be skimmed off. Finally, water glycol fluids have better thermal transfer properties over other fire-resistant fluids.