Industrial manufacturers such as steel mills, foundries, and die casters are well aware of the fire risk of their applications. Therefore, they make extensive use of fire-resistant fluids to drastically reduce the risk of fire from hydraulic leaks. For the last few decades, though, manufacturers have also had to address environmental issues. This has led to more widespread use of synthetic fluids. The fluids are considered synthetic because they contain neither petroleum oil nor water.
Phosphate esters were the first synthetic fluids and are the most fire-resistant of the synthetics. Their use has declined sharply because of poor environmental performance, limited compatibility, and high cost. Some phosphate esters have very high auto-ignition temperatures, so they are still used in specific applications, such as aircraft and power generation.
Most industries, though, largely have moved away from phosphate esters to polyol esters. Based on organic esters, polyol esters offer good inherent fire resistance and have become the most common synthetic hydraulic fluids used today. Polyol ester fluids offer good compatibility with system materials, easy conversion from petroleum oil, and excellent hydraulic fluid performance. In addition, the organic nature of these fluids gives them good environmental performance in biodegradability and aquatic toxicity.
Polyol ester fluids can cost more than twice as much as petroleum oil, so they are still used primarily only when fire resistance or biodegradability are high priorities. Other types of synthetic, fire-resistant fluids have been formulated to fill certain niche markets. Water-free poly alkalene glycols (PAGs) feature extended fluid life and good environmental performance. Silicone oils are also used in some critical applications, but these are extremely expensive.
Houghton International offers a solution with Cosmolubric HF-130 polyol ester type hydraulic fluid, which provides an affordable means for companies using heat or flame in their manufacturing processes to reduce the risk of fire and environmental concerns associated with mineral oil-based hydraulic fluid. Cosmolubric HF-130 meets or exceeds lubrication properties of mineral oil-based or other synthetic hydraulic fluids for lubricity, pump life, and oxidation stability hydraulic fluids.
Cosmolubric HF-130 has been tested and approved by Factory Mutual to be less hazardous than mineral oil. It is more difficult to ignite and produces significantly lower heat release rates in similar applications. The Mine Safety and Health Administration (MSHA) has approved Cosmolubric HF-130 as a permissible fire-resistant hydraulic fluid (MSHA Approval No. 30-21-3), finding that it resists ignition in the event of a hydraulic line rupture. Additionally, the U.S. Department of Agriculture (USDA) has granted Cosmolubric HF-130 BioPreferred status. The BioPreferred program is a USDA-led initiative to increase the development, purchase, and use of bio-based products.